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JGrass 2.0 User Manual - Università degli Studi di Trento

1. fluidturtleascii grassascil grassbyrow esriasciigrid lt Prev Next gt Cancel Figure 5 3 The first panel of the raster map wizard In this specific case there are maps only in the GRASS directory they are saved according to the logic used in GRASS This is the standard mode in which JGrass functions if you wish to load data from one of the other directories grassascii esriasciigrid o fluidturtleascii it is sufficient to choose the corresponding name from the dropdown menu Leaving the GRASS option selected and clicking on the Next button a second panel appears from where you can choose the mapset where the required map is saved This option is typical of JGrass because the program can work in multi mapset mode within a single workspace This mode is very convenient during the defining stage of your workspace and during the choice of initial maps to be processed insomuch that it is possible to access various data sources However we advise you to use workspaces with various mapsets only at this stage and to then proceed with workspaces with only one mapset In this way you can use the native GRASS commands without problems see Paragraph 6 1 and save time during data processing Otherwise it would be necessary to select the required mapset every single time both for the loading and saving of maps To view the list of maps in a mapset in alphabetical order just click on the 52 5 First
2. Figure 5 14 Settings for vector map display properties in JGrass FILL COLOR FILL TRASPARENCY l PP STROKE COLOR STROKE WIDTH STROKE DASH STROKE TRASPARENCY non acrive jet POINT DIMENSION Figure 5 15 Display properties of a vector map in in JGrass distinguished according to the type of object being By setting the display colour for the roads map to red and setting the stroke thickness to three the map display shown in figure 5 16 is obtained If you want to view all the data linked to the loaded map you only have to select the View data option from the popup menu The data are presented in tabular format for each object of the shapefile it is possible to access its respective attributes T he roads shapefile table is shown in figure 5 17 In the example the attributes are the identification number ID and the road category CAT_ID As you can see there are no data in the road description column 61 5 First Steps with JGrass Raster Layers 5 Vector Layer Point Layers 1 100158 Easting 597917 Northing 4921298 Elevation o fs Figure 5 16 View of two shapefiles in JGrass with user customized settings 62 5 First Steps with JGrass MULTILINESTRING 805 i BOB Data Viewer i the_geom ID CAT_ID CAT_DESC MULTILINESTRING 99 1 0 MULTILINESTRING f 98 5 0 MULTILINESTRING Cf g7 4 0 MULTILINESTRING Cf 96 4 0 MULTILINESTR
3. 5 a ae_AlArabiya v Font Preview enter text 5AA maps amp legends _ utils ajsjola ala El zoom Q templates amp format I 1 A 11 a 1 I oun oon ovu oou out ooh onw oow oun oon our oor mm A0 v landscape v printer selection print to pdf v ae cancel pe the amazing lt 7 gt JGrass Jgrass print editor ES CU IN AN Lo Figure 11 1 The JGrass print editor 11 Printing Among the print options there are e draw to insert drawings in the print layout such as lines rectangles external images which can be used in the cartouches of project plans for example e text to define the font type and the text settings e maps and legends to insert the displayed maps and the respective legends this option is not yet active e utils to edit the settings of the drawn objects to manage the superimpositions and remove one or more drawn objects e zoom to zoom in to the layout sheet for the definition of the objects e templates to load and save print templates Paragraph 4 3 e format to choose the the paper format and orientation e printer selection at the moment it only allows to print to pdf file e submit to launch the print process or cancel the work done To insert an object in the print layout
4. Figure 4 9 The GIS menu options This section contains all the basic GIS tools such as tools for the importation and exportation of maps in various formats including commercial formats and tools for defining the working region and its properties see figure 4 9 As has already been mentioned the term work active region refers to the calculation area while the term default region refers to display limits of the map The work region must be smaller or equal to the default region the opposite is not permissable In JGrass region management is left to the user however if you try to view a map outside of the default region an error message will appear asking you to modify the limits of your default region so as to include the selected map see figure 4 10 ene Warning Map is completely outside of the visible region Figure 4 10 Error message when you try to view a map outside of the default region In particular the JGrass GIS tools include the following possibilities import external data to JGrass The data formats that can be imported with this algorithm are ArcView ASCII grid format and GRASS ASCII format 37 4 First Start Up of the Program A AA E AN Figure 4 11 The GJS toolbar f ma a export JGrass data to be used by other external applications The formats that this EEES algorithm supports are GRASS ArcView and Surfer ASCII grids It also gives the possibility of export
5. Figure 5 41 Use of the if structure during raster algebra 000 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help 180 BARBRQAQQAQARA B55 BAR E 8 Raster Layers M claysand M geology ES Vector Layer Point Layers ma 100654 19m eo JGRASS Test Database Ready 7 Free working memory 420MB a Figure 5 42 View of a map created with the raster map calculation tool The null value introduced in the calculation syntax of the claysand map is the value corre sponding to NODATA in other words it is the value to be given to points outside of the area of interest so that they are not considered valid raster cells 5 9 Creating a Category Table The categories list allows you to associate a description to specific raster map values The categories are created with the r cats command y Let us suppose that you want to recreate the categories for the original geology map What you will need to input in the command window is summarized in table 5 1 The initial graphic interface is the one shown in figure 5 43 where the geology map has already been selected for the creation of a category table 80 5 First Steps with JGrass VALUE DESCRIPTION Table 5 1 Summary of the creation of the categories table for the geology map 0008 r cats edit choose mapset PERMANENT s choose map ge
6. 3 Raster Layers ES Vector Layer Point Layers JGRASS Test Database v97605 19m MN EastimgsoBiiz Northingi4914122 NM A YO Y Figure 5 23 Screen view of the section for which a profile is required 808 r profile mapset Profile Chart Window distance mapvalue 0 0 1635 0 f 1700 18 574 1642 0 1600 3 37 148 1641 0 maps in PERMANEN Sai 55 722 1641 0 74 296 1647 0 mot 92 871 1647 0 1300 111 44 1657 0 1200 130 01 1657 0 1100 148 59 1667 0 1659 0 1662 0 1661 0 1661 0 1661 0 1674 0 1668 0 1662 0 1651 0 1651 0 1630 0 1630 0 1608 0 0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 408 63 1608 0 427 20 1597 0 445 78 1597 0 464 35 1570 0 482 92 1560 0 coordinate of first point tan coordinate of last point 501 50 1546 0 E 592739 1 2776 8198 E 595150 2 520 07 1546 0 N 4919220 0 N 4917842 5 538 65 1531 0 Y profile Y relative profile Y max Y min Figure 5 24 Output of the profile plotting command in JGrass PUTA bottom of the profile chart window in correspondence of the information that you do not want displayed It is possible to zoom in to the graph by selecting with the mouse the part of the graph you wish to see better The selected window will be displayed in the zoom To return to the initial 68 5 First Steps with JGrass
7. Figure 7 4 Result of the interpolation done with the JGrass v contour2dem command 111 7 Special Operations 112 3 Environmental Databases Most of the environmental monitoring information made available by designated institutions has spatial information associated to it This is why GIS are used as containers and viewers for all sorts of environmental data If the amount of available data is greater than a critical limit for the good functioning of a PC or if by all means the data have to be shared among various users then databases are used There are different categories of databases In the environmental field we usually refer to two types of database point databases and spatial databases The distinction between the point database and the spatial database is precisely in their contents Point databases contain information taken in known points and therefore they contain tables with the coordinates of the points the altitude and the measures taken inserted as attributes in the table all these data are fields in the database tables Spatial databases on the other hand have a field reserved to the geography and geometry of the inserted object which refers to a specific table that contains its geometric description In these data the projection and datum are also considered as well as the relationship between objects topology For a database connection in JGrass it is necessary to define the name and position of the
8. For a stable version of JGrass an installation package is always prepared specifically for this operating system The package is a dmg package containing the application It is sufficient to click on the downloaded package to launch the installation process just like any other MacOSX application 3 2 2 The Installation Process If the installation process has launched correctly the screen display of Figure 3 1 should appear The command line in Windows can be accessed by the keyboard shortcut windows key r this launches the run window type cmd and hit enter Once you are at the command line you have to change directory to the one containing the downloaded JGrass installation file An alternative for the less expert user is click on the start menu accessories MsDOS prompt 16 3 Installation Language selection Please select your lanquage 1503 code for install instructions ok y Figure 3 1 The first panel of the installation process You will be immediately given the possibility to choose the language used during the installation procedure It can be chosen from the dropdown menu in the lower part of the panel The language choice is followed by some informative screen panels To proceed you only have to click Next After the informative panels the user is asked to accept the license chosen for JGrass that is to say a General Public License GPL There fo
9. database the connection will be through a database client 8 1 Installation and Usage of a Database Client The database client used here is called SQuirreL SQL this too is distributed with an Open Source licence all you need to do is download the software from the web site and install it The downloaded file is a jar file and therefore the installation and the problems that may arise under different operating systems are similar to those presented in Chapter 3 Installation SQuirreL SQL Client is a Java based program with graphic interface which allows you to see the structure and consult the tables and data of a database through JDBC libraries The client can be interfaced with different types of databases by simply loading the drivers that can be downloaded directly from the web site In the following example the connection to the PostgreSQL Open Source database is shown Once the basic software has been installed all you http squirrel sql sourceforge net Some practical notes for the installation of this particular software are found at http squirrel sql sourceforge net 8 Environmental Databases have to do is copy the jar file corresponding to the desired extension to the lib directory For the PostgreSQL database the driver to install is called postgresql 8 0 314 3dbc3 jar 8 1 1 Creation of the Remote Database Connections To define the characteristics of the database connection you
10. a Yaa H E pg_catalog Info Content y Row Count Columns Primary Key Exported Keys Imported Keys Indexes Privileges Column Privileges public east north elevation sample oid Ga INDEX 1639340 0 5114000 0 0 0 T2210 114850130 H SEQUENCE 1639920 0 5113900 0 0 0 741 0 114850131 H SYSTEM INDEX 1639880 0 51139000 0 0 640 0 114850132 H SYSTEM TABLE 1639360 0 5113800 0 0 0 257 0 114850133 H SYSTEM TOAST INDEX 1638960 0 5113780 0 0 0 269 0 114850134 H SYSTEM TOAST TABLE 1640060 0 5113760 0 0 0 281 0 114850135 E SYSTEM VIEW 1639280 0 5113680 0 0 0 346 0 114850136 TABLE 1639280 0 51135800 0 0 406 0 114850137 D 1640060 0 5113500 0 0 0 347 0 114850138 EH TEMPORARY INDEX 16390400 51134800 0 0 583 0 114850139 E TEMPORARY TABLE 16392400 51134600 0 0 189 0 114850140 VIEW 1639100 0 5113420 0 0 0 251 0 114850141 H PROCEDURE 1639780 0 51133000 0 0 396 0 114850142 t UDT 1639860 0 5113300 0 0 0 504 0 114850143 1638880 0 5113220 0 0 0 326 0 114850144 1639160 0 5113180 0 0 0 332 0 114850145 1640100 0 5113100 0 0 0 606 0 114850146 1639600 0 5113080 0 0 0 711 0 114850147 1639380 0 51130200 0 0 735 0 114850148 16399600 51129600 0 0 652 0 114850149 16391400 51128600 0 0 673 0 114850150 1639220 0 51128200 0 0 402 0 114850151 1638520 0 51127800 0 0 343 0 114850152 1639320 0 51127400 0 0 218 0 114850153 1639580 0 51127200 0 0 200 0 114850154 16384200 51126600 0 0 194 0 114850155 1639920 0 5112540 0 0 0 207 0 114850156 1639780 0 511244
11. IRANIAN A 5114000 0 gt 113900 0 gt 113900 0 51138000 2113 780 0 S 11s 760 0 gt 113680 0 gt 113580 0 gt 113500 0 gt 113480 0 gt 5113460 0 51134200 2113300 0 3113300 0 51132200 5113180 0 11310 N Logs Errors 0 Warnings 0 Infos 7 E d cy 10 56 31 AM CET Figure 8 10 Example of a point database query file in SQuirreL 121 8 Environmental Databases File Drivers Allases Plugins session Windows Help m 1 flanginec flanginec as moovida nh l ao XK Objects SOL select east north elevation sample from datizinco where sample gt 500 select east north elevation sample from datizinco where samples gt 500 EA ql 4 select from d select east nor select east nor select east nor select east north elevation a from datizinco where sample gt 500 Fees eteDate inte MO a es 9920 0 163 9680 0 163 9040 0 1639850 0 16401000 1639600 0 1639380 01 165939650 0 1639140 0 1639060 0 16356500 0 1635040 0 1635540 0 1635620 0 a 0 gt 113900 0 5113480 0 3113300 0 gt 5113100 0 gt 113080 0 gt 113020 0 gt 112960 0 gt 112560 0 gt 112140 0 gt 5112060 0 112020 0 111740 0 gt 111700 0 mon sample o 640 0 583 0 504 0 606 0 711 0 Pao 0 652 0 3 0 559 0 833 0 306 0 46 0 46 0 Logs Errors 0 Warnings 0 Infos 7 El A far 10 58 21 AM CET Figure 8 11 Point database query in SQuirreL You can now view the data con
12. Prosecution Description Sets the boundary definitions for a raster map Calculates linear regression from two raster maps y a b x Reports statistics for raster map layers Reinterpolates and computes topographic analysis from input raster file to a new raster file possibly with different resolution using regularized spline with tension and smoothing GRASS raster map layer data resampling capability Rescales histogram equalized the range of categoryvalues in a raster map layer Rescales the range of category values in a raster map layer Generates three or four raster map layers showing 1 the base perpendicular rate of spread ROS 2 the maximum forward ROS 3 the direction of the maximum ROS and optionally 4 the maximum potential spotting distance Makes each output cell value a function of the values assigned to the corresponding cells in the input raster map layers Creates shaded relief map from an elevation map DEM Generates raster map layers of slope aspect curvatures and par tial derivatives from a raster map layer of true elevation values Aspect is calculated counterclockwise from east Simulates elliptically anisotropic spread on a graphics window and generates a raster map of the cumulative time of spread given raster maps containing the rates of spread ROS the ROS direc tions and the spread origins It optionally produces raster maps to contain backlink UTM coordinates for tracing spread paths Recursively
13. Use of the Console Command r mode r neighbors r null r out arc r out ascil r out bin r out gdal r out gridatb r out mat r out mpeg r out png r out pov r out ppm r out ppm3 r out tiff r param scale r patch r plane r profile r proj r quant r random cells r random r random surface r reclass area r reclass r recode Prosecution Description Finds the mode of values in a cover map within areas assigned the same category value in a user specified base map Makes each cell category value a function of the category values assigned to the cells around it and stores new cell values in an output raster map layer The function of r null is to explicitly create the NULL value bitmap file Converts a raster map layer into an ESRI ARCGRID file Converts a raster map layer into an ASCII text file Exports a GRASS raster to a binary array Exports GRASS raster data into various formats requires GDAL Exports GRASS raster map to GRIDATB FOR map file TOP MODEL Exports a GRASS raster to a binary MAT File Raster File Series to MPEG Conversion Program Export GRASS raster as non georeferenced PNG image format Converts a raster map layer into a height field file for POVRAY Converts a GRASS raster file to a PPM image file at the pixel resolution of the CURRENTLY DEFINED REGION Converts 3 GRASS raster layers R G B to a PPM image file at the pixel resolution of the CURRENTLY DEFINED REGION Exports a GRASS raster
14. not spatially constant Figure 10 11 Table of the formulae and typology of use of the main types of semivariogram usually used in geostatis tics parameters number of lags to use lo max distance 1000 Figure 10 12 Second window of the procedure for the geostatistic interpolation of point data At the end of the process a window will inform you of the number of bins that were actually created and the greatest distance found between points It is very important that all the intervals into which it was decided to divide the data set figure 10 12 be actually created otherwise there will be an error during the procedure and the R connection will crash 10 0 bins were created 315 0 couples of points created With maxdist 1000 calculated maxdist 1000 0 Figure 10 13 Message informing of the subdivision of the data set into intervals for the geostatistic interpolation To continue you only need to confirm this data subdivision and the graph shown in figure 10 14 will be displayed that is the semivariogram calculated from real data To continue the procedure just close the graph window a dialog box will appear requiring you to select the model and parameters in order to best represent the calculated semivariogram figure 151 10 Statistical Processing Charts for siti50 Estimated Variogram of siti50 55 000 4 a 50 000 45 000 40 000 4 35 000 30 000 25 000 20 000 7 o Y un a W w
15. number of rows to use columns to take into account number of steps for pnorm Figure 10 1 The graphic interface of the g statistics command The parameters that can be set are 1 parameters to be calculated in the upper part of the widow 10 Statistical Processing 2 point map to be processed 3 number of rows to view in the graphic report 4 the column to take into account in statistical calculations in the case that various attributes have been specified 5 number of intervals in which to divide the complete range of data for the display of the probability density function As has already been mentioned the command only works with point maps that have been imported to JGrass as sites To do this you only need to write a file in the format described below and save it to the szte_lists directory of the working mapset The file should not have an extension and it must be written with a header that contains the name of the file and a description of the what the file contains and an entire section dedicated to the point data x y coordinates and the various attributes T he column separator is the character as shown below name sites flanginec desc Cd at ground 1639705 5114025 8 2 stationl 1639355 5114005 2 4 station2 1639485 5113725 3 0 station3 1638745 5113585 1 6 station4 1639105 5113505 4 2 stationd To view a point map you only need to choose the Display a site map option from the View men
16. of screen 0 E E Map Values Grid Legend width of screen Printarea Data Mask heigth of screen HE E E El E Northing 4923033 JGRASS Test Database Free working memory 434MB ay Q Ready Figure 5 21 JGrass view of the map scale with user defined configurations 5 5 Plotting Map Profiles In JGrass it is possible to plot the profile of a map in a section drawn on screen by means of the r profile command found in the Raster Operations of raster maps ol The graphic interface is shown in figure 5 22 it has information about the input data and the output data of the command 66 5 First Steps with JGrass The information about the input data is found on the left part of the interface and it concerns the choice of mapset from those loaded during the workspace creation process and the map for which a profile is desired in the example a profile is plotted for the elevation dem map 80 ea r profile mapset Profile Chart Window distance map value Browse maps in PERMANEN claysand dem lelevation dem esposizione_new geology 0 0000000 1 00 0 75 0 50 0 25 0 00 0 25 0 50 0 75 1 00 E map M map coordinate of first point distance coordinate of last point Y profile Y relative profile Y max Y min ok Figure 5 22 Graphic interface for the JGrass plot profile command At this p
17. the r proz command will be explained which allows you to re project raster maps from one reference system to another This command is also part of the set of native GRASS commands implemented in JGrass The version for data in vector format also exists but as of yet the graphic interface has not been created All the native GRASS command for which a graphic interface has not yet been created are executable from the console Chapter 9 As far as raster maps are concerned to re project a map from one location to another character ized by a different cartographic projection you must do as follows Should it be necessary to pass data from the Gauss Boaga zone West projection to the UTM WGS84 projection two operations are required 105 6 Creation of a New Workspace 1 the creation of a location with the desired projection in this case UTM WGS84 2 re project the necessary data with the r proj command For the first operation you only have to repeat the steps described in Paragraph 6 1 Creation of a Location but changing the projection parameters to the ones corresponding to the UTM WGS84 projection Paragraph 6 2 The process is exactly the same as the one described earlier except for the definition of the projection parameters The projection parameters to input in the window shown in figure 6 6 for the creation of a loca tion with a UT M WGS 84 projection are given below It must be remembered that Italy is partly in zone 3
18. view you have to click and drag upwards anywhere within the graph window To exit from the profile chart window click on the ok button Leaving the command active while carrying out other operations causes the program to malfunction as a result of continually loading new sections where to plot profiles every time you click on the map You will notice that upon exiting the command the section that was plotted on the map is still displayed This has become a new element that can be viewed in the legend section of the map properties window as elevation dem profile 1 It can be removed from the display by unchecking the corresponding check box or it can be completely removed by selecting the Remove option from the popup mnnu that appears when you right click on the map name 5 6 Handling Raster Map In the raster manu you will also find the map handling commands these are the commands that allow you to copy maps from mapsets or particular directories rename maps or remove them from the filesystem All these commands follow a similar logic and their respective graphic interfaces are very similar 5 6 1 Copying a Map To copy a map from another mapset or from one of the directories in which the data is stored in the format indicated by the name of the directory the command is r copy The first panel of the copy raster map wizard asks you to select the directory of origin of the map to copy by default it is GRASS and the dropdown show
19. BeanShell is a small free embeddable Java source interpreter with object scripting language features written in Java BeanShell executes standard Java statements and expressions in addition to obvious scripting commands and syntax BeanShell supports scripted objects as simple method closures like those in Perl and JavaScript tm 9 3 Execution of GRASS Commands from the Console The native GRASS commands that have not yet been provided with a graphic interface can be executed directly from the console The execution mode is the same as that used in GRASS if you do not know the syntax you only need to type the command and hit enter the respective page from the GRASS manual will be displayed on the console Unfortunately for native GRASS commands the command completion feature does not work you must therefore at least know the command name Typing the command name will either execute it directly or call its help page All the GRASS commands that do not require user interaction can be executed in JGrass This means that all the raster and vector commands which require parameter definitions at the command definition stage can be executed If the command output is a map or a series of maps they are created in the current mapset if the output is a series of information these are displayed in the console Potentially all the GRASS commands can be executed in JGrass however not all the com mands have been tested and classified as intera
20. Help Raster Layers 5 Vector Layer Point Layers 1 101919 Free working memory 215MB By Q e Figure 5 13 View of two shapefiles in JGrass with default settings By selecting Properties the window with the current map display parameters will appear like the one shown in figure 5 14 This window allows you to edit the settings simply by varying the the number that corresponds to the property you wish to modify or by clicking on the colour in order to change the display colour Figure 5 14 also shows the window to choose the display colour The parameters that can be modified shown in figure 5 15 vary according to the type of object in the file in other words it depends on whether you are dealing with polygons areas or simply lines and points 60 5 First Steps with JGrass 00 JGRASS Java GRASS Build 200604281059 File View Gis Raster Vector Extra HortonMachine Help lr fa l 606 Pick stroke color E Raster Layers El 2 Vector Layer M roads Mistreams E Remove roads Point Layers Watch data i PAS OOO Vector properties fill 178 5 3 stroke ne EJ 255 1 6 point A Preview 50 A a O E Sample Text Sample Text ED m Sample Text Sample Text HD Cancel eset gt i gt 1 Booo Read feature 116 116 Free working memory 198MB By
21. Raster menu in the Query raster maps section see figure 5 18 606 JG File View Gis Brig Vector Extra HortonMachine Help p g Emm QAQA A AAE Operations on raster maps Query raster maps E Y Rastel Handle raster maps M elevation dem pres Vector Layer Point Layers Figure 5 18 The menu to select the query raster map command The query raster map command has a handy graphic interface that allows you to choose a map and query it simply by clicking on the point you want to know the value of With this command you can also query maps that are not displayed and you can query various maps simultaneously by selecting them from the menu of available maps With each click on the map the value of the selected point will appear if various maps are queried various values will appear The value of the previously clicked point remains visible as well as its coordinates and the distance between the two points the previously selected point and the current one The graphic interface is shown in figure 5 19 where the elevation dem and geology are queried simultaneously To close the command click on the exit button 64 5 First Steps with JGrass eee JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Hel O SHSBRQQQAAARAM rot B Gima Coord 595277 8125 4916633 0 Value maps in PERMANEN _ 2 A A A geology elevation dem as 0 1492
22. Result of the JGrass g statistics command for the probability density function Probability Density 10 4 The Cumulative Distribution Function The algorithm that calculates the cumulative probability function and its interpolation with the standard normal model Gaussian model has also been implemented in JGrass By definition the cumulative probability function is the function that expresses the portion of data that does not exceed an assigned threshold value z 10 Statistical Processing D 555555 or siti_fkang gt O Ecfd and Pnorm of siti_flanginec S 0 54 Cumulated Frequency 0 3 1 Values C Columni KM pnormColumnl lv Columni r pnormColumni L Figure 10 10 Result of the JGrass g statistics command for the cumulative probability function 10 5 Geostatistical Interpolation with the Kriging In terpolator In JGrass the kriging point data interpolation algorithm has been implemented by means of the connection with R Kriging is a geostatistical interpolator it is a least squares linear regression algorithm which on the basis of known values calculates the values of the variable in the other points of a regular grid The spatial correlation of the data is expressed on the basis of available measures and specific models which estimate the value of a continuous variable in non measurement points This estimate is obtained by means of interpolation of the available data T
23. Total space Required 34 MB Available space gt 2 CB Made with IzPack http www izforge com Figure 3 5 The screen panel listing the installable JGrass packages Once the choices have been made and the Next button has been clicked you will be asked to give the JGrass installation pathname If the program is to be installed over a previous version you will be warned that all existing files will be overwritten If the installation is to a new directory you will be warned that a new directory will be created in the filesystem A practical note for the updating of JGrass if the new version of JGrass is installed in the same directory as the previous installation the user defined configurations of the older version will be maintained In this way you can avoid recreating workspaces However this is inconvenient if in the new version new commands and menus have been implemented in this case the old configurations being those of the previous version do not allow you to see the innovations implemented It will therefore be necessary to cancel the workspace from the list of available workspaces in this way it is not necessary to cancel the data saved on the hard disk and recreate it so loading the new tool bars and commands To cancel a workspace it is sufficient to right click on the desired workspace in the initial workspace selection window At the end of the installation process Windows and Linux users have the poss
24. WORKSPACE HTML REPORT ACTIVITY INDICATOR Figure 4 4 Description of the lower part of the screen with indications of the main information shown e the map visualization scale e the current resolution e the geographical coordinates of the cursor e the name of the current workspace and the names of the other workspaces that may be open e the JGrass state bar indicating what operation is active at the moment e a progress bar that indicates the progress of the graphic and numeric processes e the available RAM check e names of HTML reports that are open they can be consulted simply by clicking on this button without having to recall the process that creates them e a clock shaped icon that indicates whether the program is in a processing phase or whether it is awaiting new instructions 4 2 4 The Monitor Toolbar The display toolbar has twelve icons that launch the following commands 33 4 First Start Up of the Program es raqaqaagqa Figure 4 5 The monitor toolbar a activates disactivates the console E ETETETT activates disactivates the legend panel 3 definition of the visible data window sets the mouse pointer to its default configuration O EZ sets the zoom to the default region zoom in zoom out p zoom by dragging with the mouse hold the left mouse button and drag the pointer up or down in order to zoom in or out of the map e 9 previous zoom 2 1
25. a GRASS location f To create a GRASS workspace you must first identify a directory where the location database mapsets geographic boundaries projection information etc is stored Enter the path to an existing GRASS location or a new one to be created then click the Next button ADA Workspace Wizard Q The selected directory is not a valid GRASS location f Path Users erica grassdata 5 Description fins Caneel Figure 6 3 Warning message that the selected pathname is either incomplete or it exists already but it is not valid for saving data from the workspace that is being created Once a valid path has been defined it is possible to give a brief description to the workspace Figure 6 4 and then continue with the operation by clicking on the Next button 4008 Workspace Wizard j Create a GRASS location To create a GRASS workspace you must first identify a directory where the location database mapsets geographic boundaries projection information etc is stored Enter the path to an existing GRASS location or a new one to be created then click the Next button Path Users erica grassdata gb_ovest 3 Description Gauss Boaga su Roma40 Fuso ovest lt Prev Next gt Finish Figure 6 4 Window to select the path where to create the new workspace When you create a new workspace you will be warned that a new directo
26. creating a new workspace lt Prev Next gt Finish Cancel Figure 6 1 Presentation window for the creation of a location The following window gives the option to create a workspace compatible with GRASS The state of the art only permits you to create GRASS location mapset type workspaces the development of a data management alternative is currently being developed You have only to select the GRASS location workspace option from the menu and click on Nezt 6 Creation of a New Workspace 800 Workspace Wizard Choose the type of workspace to create from the list then click the Next buton O GRASS Location Workspace b Figure 6 2 Window to select the type of workspace to create At this point a dialog box will appear where you must specify the path where the new workspace is to be created The destination path for the new workspace is not simply the GRASS DATABASE but must be complete and contain the name of the new location If the pathname is not complete or a directory that is not valid is selected either because its empty or has other data the warning message shown in figure 6 3 appears This does not happen if you select an existing location but in this case you are not creating a new location but rather you are loading a new workspace from an existing location Paragraph 6 1 1 88 6 Creation of a New Workspace Workspace Wizard E Create
27. db connect v db select v delaunay v digit v distance v external v extract v hull v 1n ascll Description Convert a 3D ASCII raster text file into a binary 3D raster map layer import of 3 dimensional Vis5D files i e the v5d file with 1 variable and 1 time step Outputs basic information about a user specified 3D raster map layer r3 mapcalec Establishes or removes the current working 3D raster mask Explicitly create the 3D NULL value bitmap file Converts a 3D raster map layer into an ASCII text file Export of GRASS 3D raster file to 3 dimensional Vis5D file print add remove a timestamp for a 3D raster map Description Create a buffer around features of given type areas must contain centroid v buald all Creates topology for GRASS vector data Build polylines from lines Attach delete or report vector categories to map geometry Toolset to clean vector topology Imports older versions of GRASS vectors prints sets DB connection for a vector map Print vector attributes Create a Delaunay triangulation from an input vector of points or centroids Find the nearest element in vector to for elements in vector from Various information about this relation may be uploaded to the attribute table of input vector from or printed to stdout Create a new vector as a read only link to OGR layer Available drivers Selects vector objects from an existing vector map and creates a new
28. elevation type float gt sample type float gt select east north elevation sample from datizinco where sample gt 500 Line 2 Col 132 E INS NORM zinco sql 4 Find in Fies Terminal Figure 8 8 Example of an sql file to connect to a point database in JGrass As shown in figure 8 8 the syntax with which the data is inserted is extremely important Take note that each field of the file is opened with the lt gt symbols and closed with lt gt 119 8 Environmental Databases Database Querying The questions that are sent to a database in order to extract information are called queries To write queries you must respect specific parameters and syntaxes In SQuirreL you can carry out queries directly with the graphic editor In this way you can check the query results and if necessary modify the query in order to obtain the parameters needed for the following processing operations Figures 8 9 and 8 10 show examples of two queries In the first example all the fields of the datizinco table are extracted while in the second example only the north and east field of the same table are extracted File Drivers Aliases Plugins Session Windows Help Connect to spearfish Y 6 c amp El El M e O active Session 1 flanginec fla m 1 flanginec flanginec as moovida a E XK l Objects SOL select from datizinca select from datizinco select from a select from d
29. etc Rasterization The operation by which raster images are automatically obtained from vector or printed data scanner 11 2 An Introduction to GIS Record A group of contiguous fields of information which is not necessarily homogeneous and which is accessible in various ways Reference System Every projection has its own reference system from which the distances are calculated For example the Geographic Projection refers to the Greenwich Meridian and Equator intersection The UTM system refers to predetermined six degree longitudinal strips which are then subdivided into zones Italy spreads across zones 32 33 and 34 The GAUSS BOAGA sys tem a totally Italian system starts from Monte Mario in Rome and uses kilometric coordinates which are conventionally measured starting 1500km left and 2520km right of the reference meridian Resolution It is a local quality parameter of a map In vectorial maps it corresponds to the dimensions of the smallest detail represented in rasters it corresponds to the side of the pixels used S Scale The scale of a geographic map indicates how many times a portion of the Earth s surface was reduced in order to fit onto a sheet of paper It is usually expressed as a ratio between a distance on the map and the corresponding distance on the ground The scale used for a map determines the information contained and the dimensions of the area that can be reasonably rep res
30. file to a 8 24bit TIFF image file at the pixel resolution of the currently defined region Extracts terrain parameters from a DEM Uses a multi scalar ap proach by taking fitting quadratic parameters to any size window via least squares Creates a composite raster map layer by using known category values from one or more map layer s to fill in areas of no data in another map layer Creates raster plane map given dip inclination aspect azimuth and one point Outputs the raster map layer values lying on user defined line s Re project a raster map from one location to the current location This routine produces the quantization file for a floating point map Generates random cell values with spatial dependence Creates a raster map layer and vector point map containing ran domly located sites Generates random surface s with spatial dependence Reclasses a raster map greater or less than user specified area size in hectares Creates a new map layer whose category values are based upon the user s reclassification of categories in an existing raster map layer Recode raster maps Prosecution on next side 137 9 Use of the Console Command r region r regression line r report r resamp rst r resample r rescale eq r rescale r ros r series r shaded relief r slope aspect r spread r spreadpath r statistics r stats r sum r sun r sunmask r surf area r surf contour
31. imported you can select it by clicking browse e the value in the map that represents a NOVALUE to know it you will need to open the file with any text editor and normally the data value that represents a NOVALUE is indicated e the name of the imported map you can even select the destination mapset if you wish The map created in the example is dem and it can be viewed as shown in figure 6 14 In this case the working resolution is 10m which is exactly the same as that of the imported map but the active data region is decidedly bigger than the map Working in this way with an active data region which is bigger than the map that is being processed causes waste of time and memory resources it is therefore advisable to redefine the region parameters 98 6 Creation of a New Workspace 000 JGRASS Java GRASS Build 200604281059 File View Gis Raster Vector Extra HortonMachine Help 89 GARR AQQQQQQH ESO k amp a i T Easting 1635934 ES PTE a a O re 80 A Figure 6 14 Visualization of a map imported with the r in ascii command To define the active data region parameters you can use the two methods described in Paragraph 5 2 In the first example in figure 6 15 all the information to set the active data region to the same dimensions as the imported map are given It is sufficient to select the map in the map selection text box and then click the set region from map button Y
32. it is sufficient to indicate as destination of the output map the directory corresponding to the required format or else save in standard GRASS format and then copy the data to the directory corresponding to the required format at a later time To access the data in these directories it is sufficient to choose the required format initially from the dropdown menu that as default is set to GRASS format 21 3 Installation 28 A First Start Up of the Program 4 1 Introduction To launch the JGrass application the following steps must be followed depending on the oper ating system in use Windows 1 access the Windows Start menu 2 in the Programs submenu you will find the HydroloGIS submenu 3 within the HydroloGIS submenu click on the JGrass icon 4 you can create a shortcut icon directly on your desktop if you wish Linux if you have not created an icon on your desktop 1 access the JGrass installation directory 2 launch the executable file jgrass linux exe 3 if you wish you can create a link to the executable file wherever you want MacOSX if you have not created an icon in the applications bar 1 access the JGrass installation directory 2 launch the executable file jgrass macosx exe 3 if you wish you can create a link to the executable file wherever you want When JGrass is launched a check is carried out to see what version of Java is installed As of JGrass2 0 the optimal running of the pro
33. make them up Vectorization Operation by which a set of vectors are obtained from a raster image either automatically or semi automatically that is with the assistance of an operator 13 2 An Introduction to GIS 14 3 Installation JGrass is a multi platform software the same version can be installed on any of the main operating systems as long as Java is already installed Before proceeding with the installation instructions the basic system requirements necessary for a proper installation of the software are presented The installation is varies for each operating system but follows the specific standard procedures 3 1 System Requirements The system requirements necessary for the running of JGrass version 2 0 are listed in table 3 1 Requirement E mux Windows MacOSX Processor 1400 MHz 1400 MHz Power Mac G4 500 MHz Windows XP 512 MB 512 Mb 512 Mb Free disk space 90 Mb 90 Mb 90 Mb for the software no data Video card with poufer support with poufer support with pbuffer support Java Runtime jre 1 5 05 jre 1 5 05 jre 1 5 05 Environment Table 3 1 System requirements for the running JGrass 3 2 Software Installation The software is available from the HydroloGIS web site or on autorun CD ROM If you have an autorun CD ROM and the autorun option is active skip to Section 3 2 2 of this manual otherwise you go to Section 3 2 1 3 2 1 Jar File Installation If you downloaded the JGrass in
34. map containing only the selected objects If list file and where options are not specified all features of given type and layer are extracted categories are not changed in that case Uses a GRASS vector points map to produce a convex hull vector map Convert GRASS ascii file or points file to binary vector Prosecution on next side 140 9 Use of the Console Command v in db v 1n e00 v in garmin v in ogr v in region v in sites all v in sites v info v kev v kernel v label v mkgrid v neighbors v net alloc v net v net 1so v net path v net salesman v net steiner v normal v out ascil v out dxf v out ogr v out pov v overlay v patch Prosecution Description Create new vector points from database table containing coor dinates Import of EOO file into a vector map Upload Waypoints Routes and Tracks from a Garmin GPS re ceiver into a vector map Convert OGR vectors to GRASS Create a new vector from current region Converts a GRASS site_lists file into a vector file Outputs basic information about a user specified vector map layer Randomly partition points into test train sets Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel or optionally generates a vec tor density map on vector network with a 1D kernel Create paint labels for GRASS vector file and attached attributes Creates a binary GRASS vector map of a us
35. necessary for analyses data in vector format e point includes all the commands necessary for the management of point data those data that were called sites in GRASS5 e group commands for the management of group data in development e hydro hydro geomorphological analysis tools for raster maps 4 2 3 The Workspace The workspace is a virtual environment in which the resources to be used and the scope of the work to be carried out are defined 31 4 First Start Up of the Program This environment contains the personalized configurations of the main user Furthermore there are the menus and the toolbars that the user decides to use Within the workspace the geographic limits the projection used and the loadable maps are also defined As has already been mentioned in the previous chapter the user personalized configurations are found in the JGrass installation directory at the relative path etc wokspace user name There are two files config cml which contains the application configurations and workspace wks which contains the descriptions of the geographical environments the menus and the toolbars used Opening a Workspace The JGrass installation package provides a predefined workspace It includes the free data set called Spearfish By clicking on the first icon on the left of the main JGrass window a dialog box opens which lists all the pre installed and configured workspaces At the first start up o
36. outside the region e Calculate active cells to calculate the number of valid values in the active data region of a map The option only works if you choose a map from the map selection menu The number of active cells is useful in the calculation of the map area within the active data region The area is obtained by multiplying the number of active cells by the resolution in x and y e Region limits coordinates of the region limits The option only works if you select a map in the map selection box e Resolution map pixel dimensions in x and y e Number of rows and columns number of rows and columns of the map at the displayed resolution e Map selection selection box for the map from which to set the region extend it or from which to calculate the active cells Everything that has been stated for the active data region is also valid for the default region once the edzt check box has been checked The edited values can be saved to disk The saving however is not automatic and the user must check the appropriate check box in the lower part of the window to save both the active data region configuration and the default region configuration If the changes are not saved the changes will be active during the current work session but they will be cancelled upon the next start up of JGrass 5 2 1 Interactive region tool If from the GIS Region tools menu you select Interactive Region Tool it is possible to change the r
37. point data to a G3D grid volume using regularized spline with tension RST algorithm Create a Delaunay triangulation from an input vector of points or centroids Upload raster values at positions of vector points to the table 142 10 Statistical Processing Some statistical processing commands have been implemented in JGrass through its connection to the Open Source statistical calculation software R These commands are found in e r in lidar referring to the importation of point triplets and the interpolation of the data in the z column for the creation of rasters e g statistics some commands for the statistical processing of point maps 10 1 Statistical Processing of Point Maps The g statistics command allows you to view statistical reports of the significant data of a data set such as the mean the median the variance and the maximum and minimum values and to calculate and graph the probability density functions and the cumulative probability functions The most important algorithm of this set of commands is surely however the command that allows you to carry out statistical interpolation by means of the kriging geostatistical interpolator The graphic interface of this command is shown in figure 10 1 _ info about the dataset _ statistical summary about the dataset _ plot the probability density _ plot the ecdf and the pnorm _ do geostatistic interpolation map format grass UNIS EU e workshop
38. projection to use is extremely important We will now give some essential information which is however by no means exhaustive Choosing the reference system means specifying a reference ellipsoid and its orientation which define the planimetric reference surface of the portion of land of interest The cartographic projection defines the projection rules that allow us to pass from the repre sentation on the curved reference surface ellipsoid Datum to a plane reference surface map Generally for a given country the cartography is produced using a particular reference system to which a particular cartographic projection is associated In Italy generally the cartography is based on the Rome 1940 reference system and the Gauss Boaga cartographic projection More recently along with other EU nations the UTM projection and the ETRF89 reference system are being used Often the term WGS S84 is improperly used to refer to a reference system for data whose positions derive from post processing of GPS measures In GIS applications this inaccuracy does not have significant effects on the coordinates of the data as long as the reference system used is global such as the ITRF89 the WGS84 itself and for Europe the ETRF89 94 6 Creation of a New Workspace The European Petroleum Survey Group EPSG has standardized the codes that respect these types of association and so allow for an easier identification of
39. shown in figure 5 37 The graphic results obtained by simply redrawing the map clicking the CO icon is shown in figure 5 38 5 First Steps with JGrass 000 choose mapset PERMANENT HH choose map elevation d Hy HSB RGB activate startvalue startcolor endvalue endcolor Mi 1066 SELECT 1266 0 SELECT M 2 1266 0 SELECT 1466 0 SELECT M 3 1466 0 SELECT 1666 0 SELECT A A AA lt lt A _ zJJJJ JJ k M last 1666 0 SELECT 1840 SELE load original colormap PREVIEWLABEL UNDER CONSTRUCTION Mi Figure 5 37 Graphic interface for the creation of a raster map colormap in JGrass definition of the subranges and the corresponding colours 000 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help 180 68 5 iRQQQAAQAAAA B55 Be E 8 Raster Layers M aspect M elevation dem ES Vector Layer Point Layers 1 103208 Easting 590023 Northing 4926882 Elevation o JGRASS Test Database O a sos YO A Figure 5 38 The elevation dem map with new colormap If the result is not satisfactory all you need to do is recall the colormap creation command load the colormap created before and edit everything you do not like by removing and editing the subranges and by changing the colours By only changing the colour of the second data interval and recreating the colormap the image shown in figure 5 39 is obta
40. the data from the FRIDA spatial database 128 9 Use of the Console JGrass which was originally born as a GRASS graphic interface proposes to make very advanced commands and algorithms developed in the scientific field accessible to the less expert user On the other hand JGrass is also a development tool for the academic field and therefore a research tool One of the peculiarities of JGrass is that of conciliating these two tendencies furnishing a completely graphic environment and a non graphic programming environment The console is the tool that allows you to execute a command or a sequence of commands by inserting all the parameters needed for the operation manually The JGrass console is not as of yet as well structured as the GRASS console but it does provide e completion of the command name e display of the parameters required for an operation e execution of scripts for the launching of a series of commands 9 1 Execution of a JGrass Command from the Console To display the console click on the icon the JGrass interface will be modified displaying the console in the lower part of the screen The console shown in figure 9 1 is in its standard configuration JGrass 008 Figure 9 1 The JGrass console in its standard configuration The console has e prompt that is a symbol that indicates that the console is ready to receive input command to enlarge the console e command to re
41. the geographical East therefore e NORTH 90 31 5 First Steps with JGrass E a ODO r cats edit choose mapset PERMANENT HH choose map geology 4 activate value label M10 nodata M21 metamorphic M32 transition Y 4 3 igneous M54 sandstone M65 limestone M 7 6 Shale M 87 sandyshale Y 9 8 claysand N Y last 9 sand i load original categories Figure 5 44 Creation of the categories list for the geology map in JGrass e WEST 180 e SOUTH 270 e EAST 360 or 0 By introducing the intermediate directions NE NW SW SE we can divide the map into the intervals listed in table 5 2 The steps to solve this problem are two 1 create a new aspect map aspect new that has the values assigned in table 5 2 figure 5 45 rather than the original aspect values in degrees using the raster map algebra tool r mapcalc 2 create the category table for the new map and associate the legend of the new map to the original map using the category editing tool r cats OBS r mapcalc parameters 6 if Saspect gt O amp amp aspect lt 22 5 1 if aspect map format grass gt 22 5 amp amp aspect lt 67 5 2 if aspect i gt 67 5 amp amp aspect lt 112 5 3 if aspect zlone reclass HE gt 1125 3 amp amp aspect lt 157 5 4 if aspect 2 gt 157 5 amp amp aspect lt 202 5 5 f Saspect Y WN E alee del dl e 2 e da 3 ee Jan
42. traces the least cost path backwards to cells from which the cumulative cost was determined Category or object oriented statistics Generates area statistics for raster map layers Sums up the raster cell values Computes direct beam diffuse and reflected solar irradiation raster maps for given day latitude surface and atmospheric con ditions Solar parameters e g sunrise sunset times declination extraterrestrial irradiance daylight length are saved in a local text file Alternatively a local time can be specified to compute solar incidence angle and or irradiance raster maps The shadow ing effect of the topography is optionally incorporated Calculates cast shadow areas from sun position and DEM Either A exact sun position is specified or B date time to calculate the sun position by r sunmask itself Surface area estimation for rasters Surface generation program from rasterized contours Prosecution on next side 138 9 Use of the Console Command r surf fractal r surf gauss r surt idw r surf random r terraflow r texture r thin r timestamp r to vect r topidx r topmodel r transect r univar r univar sh r water outlet r watershed r what Prosecution Description GRASS module to create a fractal surface of a given fractal dimen sion Uses spectral synthesis method Can create intermediate layers showing the build up of different spectral coefficients see Saupe pp 106 107 for an example of th
43. you only have to select the object or image from the menu and then use the mouse to select the area the object should cover in the print layout The term object refers to objects such as lines and polygons as well as to displayed text and maps An example of the print of a map with its respective legend taken from the JGrass display window is shown in figure 11 2 Warning for certain combinations of operating system and video card the visualization of the map in the layout sheet may not work giving a completely black window The printing of maps in JGrass is done at the same scale as the on screen display You need to set the display scale which will then be used in the prints 158 11 Printing JGRASS eave GRASS Build 200602201023 BEERA the amazing JGrass print editor II II II A II A E A A A EU A E O 1 50 100 150 200 250 300 350 File View Gis Raster Vector Extra HortonMachine Help ou oor our oon oow oun onw oof outs landscape printer selection print to pdf submit oou oum oon Fi oun the amazing Flanginec s jGrass 5 print editor oon Figure 11 2 The JGrass print editor 159 11 Printing 160 12 Uninstalling To uninstall the program you only need to click the uninstall icon and the uninstall wizard will launch which also gives you the possibility to remove the JGrass directory from the filesy
44. 0 elevation dem Coord 598578 9375 4920899 0 Value elevation dem geology 1348 0 4 0 IO Easting 59 8214 _ Northing 4923342 i 5394 087713935045 100 Free working memory 498MB amp Figure 5 19 Graphic interface for the query raster map command 5 4 2 Querying Vector Maps The command used to query vector maps is the only vectorial analysis command that is currently integrated in JGrass it is found in the Vector menu as shown in figure 4 14 A graphic interface has also been implemented for the d what vect similar to the one seen for the d what rast command see figure 5 20 which gives a menu of the available maps in this case only the maps that have been loaded as the command queries shapefiles the coordinates and attributes of the clicked point and the distance between two successively clicked points The only peculiarity of the vector command with respect to the raster command is the number in the upper left of the interface which is called snap This represents the maximum distance at which it is possible to click in order to select an object The snap value is specific for every map indicatively you can set the map resolution as the initial value If by clicking in a point the data relative to two objects appear it means that both objects are less then the snap distance from the clicked point In this case in order to select one object it is sufficient to
45. 0 next zoom when you work with map visualizations at different scales it may be useful to alternate the zooms rather than just returning to the previous zoom 11 A window zoom it allows you to define the extent of the visualized area on the screen 12 pan you can move the map by dragging it with the mouse We would like to point out that if your mouse is set in standard mode it is possible to zoom in or out by scrolling the scroll wheel while you can pan by holding down the scroll wheel and dragging to a new position 34 4 First Start Up of the Program 4 2 5 The Menu Bar The menu bar includes all the operations that can be carried out in JGrass If during installation you chose to load all the tool bars then the main menu will have eight distinct dropdown menus File View Gis Raster Vector Extra HortonMachine Help A description of each now follows File File Vie Gis Raster Vector Extra HortonMachine Help Oe SEBS AQQQAQae i Save As ip Exit Figure 4 6 The File menu This menu contains all the tools necessary for the creation of a new workspace for loading an existing workspace for saving the settings of the work window and for changing the settings of the program See figure 4 6 For more details on how to customize JGrass please refer to Paragraph 4 3 39 4 First Start Up of the Program View The View menu contains all the tools for the display of raster and vector maps By s
46. 0 0 0 0 180 0 114850157 fflanginec public TABLE datizinco O AA Figure 8 7 Viewing data from the flanginec database Content tab in SQuirreL At this point you have all the information necessary to process the data in JGrass 3 2 How to Interface JGrass to the Database The connection created in SQuirreL is not enough for JGrass to access the data It is a rather the starting point and surely the necessary condition in order to to use the data To access the data you need to give some information to JGrass regarding the type of database to connect to and this information varies depending on whether you are dealing with a point database or a spatial database 8 2 1 The Interface for a Point Database Point databases not having geometric information have to be integrated into a JGrass workspace The information about the point databases is in a file in the sql directory of the mapset Paragraph 3 5 If this directory was not made during the creation of the new workspace all you have to do is create it externally to JGrass with the classic commands for creating directories in a filesystem There are no graphic modes to create the file you will have write the file according to the specifications of the given example with a text editor and save it with a sql extension in the sql directory of the mapset The extension is of the utmost importance insomuch as JGrass uses this 118 8 Environmental Databases type of fil
47. 066 00 Legend WA Legend 1143 40 Printarea 1220 80 Data Mask 1298 19 1375 59 1453 00 1530 40 1607 80 1685 19 1762 59 1840 00 vezes 19m MN eo JGRASS Test Database Ready Free working memory 389MB Bs Figure 5 10 JGrass view of the elevation map and its legend created with the parameters shown in figure 5 9 0009 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help 180 BERBRQAQQAQARHA BSS BO E 8 Raster Layers C elevation dem M geology y Vector Layer Point Layers sandy shale claysand sand AF vers 19m MN Eastingio9263 Northing 4924176 E J E m O a L JGRASS Test Database x GRASS Test Database Ready Free working memory 302MB Bs Q Figure 5 11 JGrass view of the geological formations map and its legend other words to display a legend you must also display the corresponding map along with other maps if the need arises 58 5 First Steps with JGrass 53 2 Vector Data in shapefile format is launched The initial window asks you to select the path to the file to be By clicking on the icon the vector map display wizard for the visualization of vector maps displayed in fact you can load this type of data from any directory of the filesystem In the Spearfish dataset a directory called shapefiles has b
48. 1 spearfish public TABLE archsites 1 1 Figure 8 14 Viewing the Spearfish spatial database data in SQuirreL In each data table other than the specific data of the table there are fields that refer to the geometry and position of each object 124 8 Environmental Databases The FRIDA Test Database An example of connection to a spatial database with different types of objects such as points lines and polygons is the free vector dataset called FRIDA it refers to the city of Osnabrueck in Germany To view these data you need to create a new workspace that refers to a location with the same reference system and cartographic projection as the dataset The method to create a new workspace is the same as that described in Paragraph 6 1 Creation of a Location The data is given in the UTM reference system with Potsdam Datum and the Bessel Ellipsoid Looking through the options of the EPGS file you will find that the reference code is 31463 DHDN 3 degree Gauss zone 3 This operation however is not sufficient for defining all the projection parameters In the following window you will have to insert the region limits and the towgs84 parameter which are as follows e towgs84 606 0 23 0 413 0 e north 5801000 e south 5787000 e east 3445000 e west 3427000 To conclude the database connection you will now have to write the configuration file which has to be saved in the respective directory of the locatio
49. 1 1 The JGrass GIS The research centre for the development of the algorithms implemented in JGrass is the De partment of Civil and Environmental Engineering of the University of Trento Italy and CUDAM University Centre for the Defence of Mountain Environments also at the University of Trento The development centre is HydroloGIS of Bolzano Italy although there are other developers at CUDAM in Trento and at ICENS in Kingston Jamaica The JGrass starting point is GRASS GIS which currently represents the most important Open Source project in the GIS field GRASS is slowly evolving towards an attractive solution for the commercial and productive sectors The biggest obstacle to the commercial blooming of GRASS is without doubt its versatility problem Many professionals use Windows and Mac OS as the preferred operating systems and many businesses do not provide the possibility of using Linux which is the operating system upon which GRASS development is based JGrass developed to simplify the use of GRASS on the various platforms has set the following objectives e versatility the possibility to run GRASS on Windows Unix Linux and Mac OS indifferently 1 Introduction write once run everywhere e the possibility for anyone by means of the framework that has been created to develop with ease additional modules particular functions and application oriented interfaces by means of XML scripting e scripting the p
50. 106 6 Creation of a New Workspace steps that allow you to define the working mapset and the toolbars to be loaded 0080 Workspace Wizard Select GRASS geographic window cacai The GRASS workspace defines the geographic window also known as extent projection mapsets and default raster resolution Edit the window parameters listed below some of which have already been set then click the Next button Value WGS 84 UTM zone 32N 32632 lt Prev Next gt Finish Cancel Figure 6 24 Summary window of the UTM WGS 84 projection parameters in the workspace wizard for the creation of a new workspace The name chosen to be displayed in the initial window of the load workspace wizard when you have data in different projections should contain some indication of its projection in this case for example you can call it trentino utm Once the new workspace with UTM projection has been created you can access it and with the r pro7 command re project the data from the Gauss Boaga zone West location This command requires as input e the name of the mapset with the input map which is selected by means of the browse button e the name of the input map which must be inserted manually e the name of the output map e the resolution of the output map which is already set to the resolution value of the current workspace e the interpolation method to be used e the choice to list t
51. 2 and partly in zone 33 of the northern hemisphere in the UTM projection representation You will have to select from the EPSG file by means of the graphic interface the parameters corresponding to 32632 WGS 84 UTM zone 32N By writing UTM WGS84 in the provided text box and scrolling through the results in the dropdown menu you will be able to identify the desired projection as shown in figure 6 23 006 Workspace Wizard Select GRASS location projection The projection is a mathematical means of displaying the 3 dimensional geographic information on a two dimensional computer screen Different projections are used for different types of maps for example a projection that accurately represents the shapes of the continents will distort their relative sizes A Select the projection to use or Custom to define your own then vi GS 84 UTM zone 285 GS 84 UTM zone 29N GS 84 UTM zone 295 S 84 UTM zone 335 B WGS 84 UTM zone 34N proj utm 4 UTM zone 345 one L Pr E IN EM zon Filter EPSG Codes wgs 84 lt Prev Next gt Finish Cancel Figure 6 23 Choosing the UTM WGS 84 projection parameters in the workspace wizard for the creation of a new workspace For better data management values are given to the region limits even in this case the values are typical for Trentino The result is shown in figure 6 24 Clicking Nextto continue to the successive
52. 4281059 File View Gis Raster Vector Extra HortonMachine Help Bik QQQQ Dew E E a q j ANS t IA PAY Q T Le ers A SE AV rae a a VR IR NS rr AN X NOS x d j A gt E z A o a AMAT A CLS SEN NAAA M LA fi j A Y A re p E NA PO A A dd 5 E s 4 en E pe ON ry 319 0 2 po 7 YS o SF ee a os if A y Y t 1 a A a bers 1 om x ae x nS L q yp A TEN VA J k wee nh Ls JOIO x y f wy hy if Y LF e al d DLEET gt a z R nf A 2 4 e i j Br 1 5i y i o Easting 1625888 _ Northing 5120178 Trentino Ready Free working memory 228MB ay Q Figure 6 22 Enlargement of a portion of the technical map of the Province of Trento imported with the r in gdal command 6 3 2 Importing Vector Maps To import vector maps it is sufficient to view them with the d shapefile command Paragraph and select the directory of origin In JGrass the shapefile format is kept as a swap format and all processing starts off from this format If you use the native GRASS commands that have their own specific format for vector maps the command itself will carry out all further processing to pass from one format to another you only have to specify the names of initial and final maps which will be in shapefile format 6 4 Data Re Projection In this section
53. 54 File View Gis Raster Vector Extra HortonMachine Help 180 BAB QQQAQQACAA 255 BR Raster Layers ys Vector Layer Point Layers Easting 609300 Northing 4925422 Elevation o est Database ocr YO A Figure 5 49 Raster map created with the r correct polygon tool 3 5 First Steps with JGrass 36 6 Creation of a New Workspace 6 1 Creation of a Location To create a new workspace you have to select the New Workspace command from the File menu as shown in figure 4 6 Actually what in JGrass is referred to as a workspace is the GRASS location concept Paragraph 3 5 A location is the reference directory for all the data and work settings of a project in a specific JGrass workspace its structure is that defined in Paragraph 3 5 Once you have selected the option to create a new workspace a presentation window appears Figure 6 1 just click Next to continue 808 _ Workspace Wizard Create workspace JGrass provides a workspace as the basic application environment Workspaces can be geographic locations with boundaries mapsets menus etc or programs such as database managers graphics editors and the like Workspace definitions are stored either in the system workspace area where they are available to all users or a users profile area where they will be available to only the selected user Click on the Next button to start the process of
54. BLE simpleName datizinco G SYSTEM VIEW type TABLE gt TABLE 8 TEMPORARY INDEX a TEMPORARY TABLE VIEW PROCEDURE a UDT flanginec public TABLE datizinco Figure 8 5 The flanginec database structure in SQuirreL J E AS gt UU YN gt e Objects SQL ES a schema ban IDs Versions Hf pg_catalog Info acon Content LAL Row Count Columns ne einai Primary NA Exported Keys Imported Keys Indexes Privileges oe es Column Privileges public COLUMN TYPE_N COLUMN DECIMAL_DIG IS_NULLAB COLUMN REM DATA BUFFER_LEN NUM_PREC_R NUL GB INDEX eat float4 4 OO YES lt null gt lt n gt 7 lt null gt 10 1 a SEQUENCE north float4 4 0 YES lt null gt lt null gt 7 lt null gt 10 1 SYSTEM INDEX elevation float4 4 0 YES lt null gt lt null gt 7 lt null gt 10 1 SYSTEM TABLE sample float4 4 0 YES lt null gt lt null gt 7 lt null gt 10 1 SYSTEM TOAST INDEX SYSTEM TOAST TABLE SYSTEM VIEW TABLE DEE EEE VPRPPRP TEMPORARY INDEX TEMPORARY TABLE VIEW PROCEDURE UDT Fe PEPER flanginec public TABLE datizinco Figure 8 6 Type of data in the flanginec database Columns tab viewed with SQuirreL 117 8 Environmental Databases 3 1 flanginec flanginec as moovida 2 oy E A y gt uu Y gt rc Objects SQL gt flanginec Row IDs Versions H E information schema gt y
55. E E fas i a o E a nw 15 000 10 000 4 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 lags M estimated estimated Figure 10 14 Variogram of the data contained in the point map 10 15 In this way a mathematical formula is assigned to the semivariogram which will be used in the actual interpolation parameters fitta con modello esponenziale F g metodo di fitting i fitta modello gaussiano 7000 43000 iterazioni passo Figure 10 15 Dialog box for the selection of the semivariogram model that best describe the real semivariogram and for the definition of the Gaussian model parameters 152 10 Statistical Processing Variogram of siti_flanginec ICO un un a uw ow E E fas a o S E w n EE CUENTA A AEREN AAEREN EEE SON EEN AES LEEREN SEEEN A SPEAN ee DE A eee 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 lags E fitted model W estimated v fitted model estimated Figure 10 16 Graph with the superimposition of the real semivariogram and the one obtained with the Gaussian model using the parameters defined in the interface of figure 10 15 To continue just close the graph window a message will appear asking you if you wish to continue with the interpolation procedure or if you wish to redefine the model parameters in order to better represent t
56. ING Cf 95 4 0 MULTILINESTRING Cf 94 A 0 MULTILINESTRING f 93 4 0 MULTILINESTRING f 92 A 0 MULTILINESTRING f 91 4 0 MULTILINESTRING f 90 3 0 MULTILINESTRING f g 5 0 MULTILINESTRING ii 89 3 0 MULTILINESTRING i 88 3 0 MULTILINESTRING f ay 1 0 MULTILINESTRING f 86 1 0 MULTILINESTRING f a5 3 0 MULTILINESTRING f Bd 2 0 MULTILINESTRING f a3 1 0 MULTILINESTRING f 825 3 0 MULTILINESTRING f 824 3 0 MULTILINESTRING f 823 1 0 MULTILINESTRING f B22 1 0 MULTILINESTRING f 821 3 0 MULTILINESTRING f 820 1 0 MULTILINESTRING f a2 1 0 MULTILINESTRING f 819 3 0 MULTILINESTRING f 818 1 0 MULTILINESTRING f 817 A 0 MULTILINESTRING f 816 5 0 MULTILINESTRING Cf 815 2 0 MULTILINESTRING Cf 814 1 0 MULTILINESTRING f 813 2 0 MULTILINESTRING f 812 1 0 MULTILINESTRING f 811 1 0 MULTILINESTRING ti 810 E 0 MULTILINESTRING ff al 4 0 MULTILINESTRING f 809 1 0 MULTILINESTRING f 808 Pa 0 MULTILINESTRING 807 2 0 L MULTILINESTRING f 806 E 0 1 0 7 Jall Figure 5 17 Viewing the attributes linked to a shapefile in JGrass 63 5 First Steps with JGrass 5 4 Map Query All the maps viewed in JGrass be they in raster or vector format can be queried in other words it is possible to know the value of a specific point of the map 5 4 1 Querying Raster Maps The command used to query raster maps is d what rast it is in
57. JGrass 2 0 User Manual The HydroloGIS Team Andrea Antonello amp Silvia Franceschi In collaboration with CUDAM Riccardo Rigon amp Alfonso Vitti UNIVERSITA DEGLI STUDI DI TRENTO Dipartimento di gagnara Civile e Ambientale June 2006 ISBN 10 88 8443 145 X ISBN 13 978 88 8443 145 5 Andrea Antonello andrea antonello hydrologis com Silvia Franceschi silvia franceschi hydrologis com Riccardo Rigon riccardo rigon ing unitn it Alfonso Vitti alfonso vitti ing unitn it HydroloGIS www hydrologis com Translation by Joseph E Tomasi Thanks to Vanna Antonello the patient guinea pig user Readme This ebook was written by Silvia Franceschi Andrea Antonello Riccardo Rigon and Alfonso Vitti HydroloGIS Universit degli Studi di Trento Department of Civil and Environmental En gineering It is distributed according to the CREATIVE COMMONS deed Attribution NoDerivs 2 5 According to this license type you are free to e copy distribute display and perform the work e to make commercial use of the work Under the following conditions e Attribution You must attribute the work in the manner speciied by the author or licensor e No Derivative Works You may not alter transform or build upon this work e For any reuse or distribution you must make clear to others the license terms of this work Any of these conditions can be waived if you get permission from the copyright holder Your fair use an
58. Rome Should it be necessary to create a location in which to import data acquired with commercial GPS instruments that are therefore not post processed or data that comes from official cartography the EPSG reference codes are e for geographic coordinates 4326 WGS 84 latlong e for UTM cartographic coordinates Italian zones 32632 WGS 84 UTM zone 32N 32633 WGS 84 UTM zone 33N In the case of post processed and ETRF89 compliant GPS data e for geographic coordinates 4258 ETRS89 e for UTM cartographic coordinates Italian zones 25832 ETRS89 UTM zone 32N 25833 ETRS89 UTM zone 33N In the case of coordinates in the ED50 EuropeanDatum 1950 reference system e for geographic coordinates 4230 ED50 e for UTM cartographic coordinates Italian zones 23032 ED50 UTM zone 32N 23033 ED50 UTM zone 33N 96 6 Creation of a New Workspace An example of UTM ED50 cartography are the excursion type maps printed by Tabacco and Compass NOTA BENE 1 For all GIS applications the difference in coordinates between the WG5S84 system and its ETRF89 materialization is not appreciable and therefore negligible The creation of a location in either one of the two systems is equivalent 2 There is no significant difference in this context between writing E TRF89 and ETRS89 3 The difference between coordinates expressed in the ED50 system and the ETRF89 or WGS84 system is on
59. Steps with JGrass 608 Choose Raster Map Wizard gc Location spearfish E PERMANENT aspect elevation dem geology lt Prev Finish Cancel Figure 5 4 The second panel of the raster map wizard list of available maps sign in front of the desired mapset For the Spearfish data set it is sufficient to click on the sign before the PERMANENT mapset a list of the maps in the mapset will then be displayed as shown in figure 5 4 At this stage all you have to do is select the map that you wish to view in the example the selected map is elevation dem and click Next In JGrass maps are not displayed in successive parts but rather in one single block it is therefore necessary that the program read the entire map load it to memory and then display it The progress of the map display operation is shown in the JGrass Progressbar in the lower part of the screen see figure 4 4 The map chosen for display in the example should appear as in figure 5 5 If you repeat the display procedure choosing the aspect map you will obtain a superimposition of maps as shown in figure 5 6 The aspect map maps the slope exposure or aspect and it is often displayed as a base for image processing in JGrass because it gives the idea of working in a 3D environment In this way all the maps in the loaded mapset can be viewed In JGrass any map that is suc cessively chosen for display will be superimposed over the maps already disp
60. Use Driver Properties Warning Passwords are saved in clear text Figure 8 2 Creation of a new database connection in SQuirreL In this way you can connect to point databases such as flanginec Trentino and spatial databases indifferently by specifying the connection name and the source URL For example you can connect to the spatial database of Osnabrueck figure 8 3 or to the spearfish database figure 8 4 Add Alias Mame asnabrueck Driver y PostgreSQL URL User Mame moovida Password Auto logon Connect at Startup Use Driver Properties Warning Passwords are saved in clear text Figure 8 3 Creation of a new spatial database connection in SQuirreL 115 8 Environmental Databases Add Alias Mame speartish Driver w PostgreSQL Men URL User Marne moowida Password Petrer C Auta logon C Connect at Startup C Use Driver Properties Warning Passwords are saved in clear text Figure 8 4 Creation of a new spatial database connection in SQuirreL 8 1 2 Connection and Data Visualization To access a database from JGrass first and foremost you need to establish a connection with SQirreL This connection must remain active for the duration of the visualization and use of the data from the database To connect to a created database you just have to double click on the name of the database or select the option from the dropdown menu Once all the connection data
61. abase record is associated to each element which contains all the attributes of the represented object Raster data represent the real world by means of a matrix of cells these are usually square or rectangular and are known as pixels Each pixel contains information about what it represents on the land surface The pixel size usually expressed in the same units as the map metres kilometres etc is closely related to the precision of the data Vector data and raster data are suitable for different uses Vector maps is particularly suited to representing data that vary in a discrete way e g the location of rubbish bins in a city street maps land use maps On the other hand raster maps are more suited to representing data that vary continuously e g digital terrain models or a maps of the steepness of slopes 2 4 Functionality A GIS allows different data to be put in relation to each other on the basis of a common geographic reference system so as to create new information from existing data A GIS can interact with the user in many ways and a set of tools make personalization and adaptation to specific problems easy Normally a GIS offers spatial analysis features that is to say the transformation and processing of the geographical elements of the attributes Some examples of these processes are e Topological overlaying where the superimposition of the elements of two different thematic maps is used to create a ne
62. ains the Java libraries of the packages that make up JGrass e lib it contains the native system libraries e spearfish it contains the test data package installed during the installation of JGrass e uninstaller it contains the executable files for uninstalling the application e grasscommands it contains the executable files for the native GRASS commands necessary under the Windows operating system e src it contains the source code Given that the modification of XML configuration files is recommended only to advanced users the most interesting things to improve and customize the use of JGrass are found in the etc directory Attention must be brought to its subdirectories e prop it contains the command and graphic interface configuration files in different languages e g it is possible to modify the number of cells displayed when a map is corrected with the command r correct by changing the number contained in the file r_correct properties e scripts it contains all the scripts that are directly executable in JGrass e workspace contains all the workspace configurations and those of the single user it must be noted that it is not yet possible to have various users and differentiate access to data according to the user The most important files in this section are config cml and workspace wks These files contain the program settings font size position of the tool bars position and size of the scale bar and the legend and
63. ansparency Factor 10 7 X Position 2b 0 Y Position width heigth boxwidth 20 09 box height correction value for tuning o Pap tegend Display Object Properties OK Cancel Figure 5 9 Definition of the map legend properties It is possible to set the map legend position its transparency factor and the size of the box that contains the legend The legend will vary according to the map to which it refers not only in its values but also in its form The legends created for the elevation dem and geology maps shown in figures 5 10 and 5 11 are very different from each other the former is a continuous legend in which the colour scale used in the map is displayed along with some reference values while the latter is a discrete legend where for each specific colour there is an associated value or in this particular example the name of the corresponding geological formation This difference is due to the fact that for the geology map the values were categorized and the legend refers to these categories Warning The display of a legend is conditioned by the display of the corresponding map In ov 5 First Steps with JGrass 00098 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help 1805 BEBLKQAQADQAQE 255 BR Map Grid North Arrow Map Scale Map Values Grid 1
64. appears by selecting Properties from this menu The raster s alpha transparency parameter is defined in this window a value of 1 indicates that the map is not transparent the transparency is increased by reducing the value of the alpha factor Display properties With the Legend window displayed you can define many map display properties that have already been presented in Paragraph 4 4 You can do this by clicking on the Properties tab at the bottom of the panel In this window the same options as seen in figure 5 7 are proposed again and for each one of these it is possible to customize the specified default parameters To do this you will need to view the contents of each option by clicking on the that precedes the name and then right clicking on the desired option From the Proprieties menu i t is then possible to define the new parameters Figure 5 8 shows a display example with e Map grid displayed with a NS and EW resolution of 1000m e North arrow displayed 55 5 First Steps with JGrass AAA AAA Add dd dd de eee meam JGRASS Java GRASS Build 200605080954 i File View Gis Raster Vector Extra HortonMachine Help 8 Raster Layers elevation dem M aspect 7 geolo x Remove aspect fs Vector L Point La S Watch data aK Properties x6759 om A ines o1 8 Northing 4926376 Free working memory 411MB By a Y Figu
65. as always been one of the main problems of Open Source GIS Printing the result of the various operations is of fundamental importance in divulging and presenting results In JGrass a handy print editor for the printing of maps that are displayed on screen on various paper formats is in its development stages It is possible to prepare a print with a predefined template or draw and insert new objects and text Before describing the operations that must be carried out during the printing phase it is im portant to clarify that at the state of the art the printing module is not yet optimized This does not mean that the printing feature does not work or that it is totally unusable but it advisable to print only in A4 format or at the most in A3 because large prints of the maps are not of good quality The part of the module which is in development is expected to redraw the map at the scale of the sheet of paper so as to always have the greatest resolution possible for the print Unfortunately as of yet it has not been possible to develop the algorithm completely RA To print you only need to click on the E icon and the print editor will open figure 11 1 The editor is split into two parts on the left there are all the print options on the right the print layout is displayed D o e amazing SS 22 To AT a a AO RS AO A ent otal oat A a A O AS PRA DO AO draw l ele a ir text
66. asciigrid fluidturtleascit grassasciu Copying a raster into one of these directories means exporting the file into the format specified by the name of destination directory Vector 606 JCF File View Gis Raster Rist Extra HortonMachine Help Mr dies QAQAAQ SE Operations on vector maps E v contour2dem Query vector maps F Figure 4 14 The Vector menu options Originally JGrass only dealt with raster maps and for a long time it was a distributed GIS dedicated solely to hydro geomorphological environmental analysis Future developments include the development of a vector data handling environment which goes from displaying maps to in putting and modifying points lines and polygons For the development of this we have chosen 40 4 First Start Up of the Program to follow the Open GIS Consortium standards which propose the shapefile format as the saving and swap format for vector maps This policy is somewhat in contrast with GRASS policy total compatibility is guaranteed however with the vector part of GRASS5 but total compatibility is not yet available with GRASS6 In this section there are only two commands at the moment the one that allows you to query the maps and so see the associated data table see figure 4 14 and a real vector analysis tool which allows you to convert a contour line map into a DEM raster by means of interpolation The command is v contour2dem and the corresponding icon at the mo
67. ast the GNU General Public License is intended to guarantee your freedom to share and change free software to make sure the software is free for all its users This General Public License applies to most of the Free Software Foundation s software and to any other program whose authors commit to using it Some other Free Software Foundation software is covered by the GNU Library General Public License instead You can apply it to your programs too When we speak of free software we are referring to freedom not price Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software and charge for this service if you wish that you receive source code or can get it if you want it that you can change the software or use pieces of it in new free programs and that you know you can do these things PUTA accept the terms of this license agreement O do not accept the terms of this license agreement Made with IzPack http www izforge com M Figure 3 2 Screen shot of the software s license 606 IzPack Installation of JGrass 2 Please read the following information PLEASE READ CAREFULLY THE FOLLOWING INSTALLATION INSTRUCTIONS complaining afterwards doesn t help REQUIREMENTS To run JGrass needs a java runtime environment to be installed If you don t have one on your machine you can download it at http java sun com j2se R CONNECTIVITY I
68. aster Layers M dem ES Vector Layer M flangi_contour Es Point Layers Legend 12559 som MN JEastingu 36106 Northingi5uga32 Elevation o Trentino xf Ready Free working memory 228MB ay Figure 7 2 The resulting map from the r dem2contour operation superimposed onto the original terrain model 7 2 Creating a DEM from Contour Lines Just as useful is the possibility to create a DEM from contour line data If the contour data is in shapefile format it is possible to read the file and interpolate the contour lines to obtain a map of the terrain model The command to use in this case is v contour2dem from the Vector menu figure 7 3 This command is very simple and requires as input data the name of the shapefile with the contour lines the destination folder for the output file and the name of the output file The resolution of the output map will be that of the current mapset the one displayed in the lower part of the screen parameters shapefile of contour lines sktop cile curvas_nivel_valpso shp field name to take for elevation SPOT map format grass interpolated raster map idern workshop Browse cancel stop Figure 7 3 The v contour2dem graphic interface in JGrass 110 7 Special Operations The process of interpolating the contour li
69. ath apps gb_ovest scripts gt lt scripts gt lt tools path apps gb_ovest gt lt tools gt lt lib path apps gb_ovest lib gt lt lib gt lt menu path apps gb_ovest menu xml gt lt menu gt E lt workspace gt Y Figure 6 9 Window requiring the name to be displayed in the loading phase of the new workspace The last step of the wizard gives you the possibility to decide which toolbars to load in the new workspace by default depending on the data processing that wish to carry out see figure 6 10 Click Next to finish the creation of the new workspace If all went well the window shown in figure 6 11 appears Click Finish to exit the wizard 92 6 Creation of a New Workspace 808 Workspace Wizard Toolbars and Menus selection JGrass has a very flexible toolbars and menus creation system Everything is made through XML definitions Select below the supplied templates of toolbars and menues then click the Next button vi basin Y basin_related_analyses Y DEM_manipulation Y displaytool Y geomorph Y hillslope_analyses Y hydro_geomorphology Y importexport Y maptools Y menu Y network_related_measures l statistics T lt Prev Next gt Finish Cancel Figure 6 10 Dialog box for the selection of the toolbars of the new workspace 000 Workspace Wizard Workspace definition complete The JGrass workspace definition is now c
70. ation e Geometric referring to the cartographic representation of the objects represented such as shape point line or polygon dimension and geographic position e Topological referring to the reciprocal relationship between the objects connection adja cency inclusion etc e Informative referring to the data itself numerical text etc The GIS manages all this information by means of a relational database The aspect which characterizes GIS is the geometric one it stores the position of an object by means of a real projection system which defines the geographic position of the object A GIS can manage data coming from different projection and reference systems simultaneously e g UTM or Gauss Boaga As opposed to cartography on paper the scale in a GIS is a quality parameter of the data and not of the visualization The scale value indicates the number of digits of the georeferencing coordinates to be considered significant 2 An Introduction to GIS 2 3 Types of Geographic Data The real world can be represented in a Geographic Information System by two main types of data vector data and raster data Vector data are made up of simple elements such as points lines and polygons which are encoded and stored on the basis of their coordinates In a GIS a point is identified by its real coordinates xl yl a line or a polygon by the position of its nodes x1 yl x2 y2 An informative dat
71. atizinco Results fests i Mi sda te ar PO Ea ql O 9340 0 163 9920 0 1639880 0 1639360 0 1635950 0 1640060 0 162 9280 0 169280 0 16400600 16390490 0 1639240 0 16391000 1639750 0 16398650 0 1635880 0 1629160 0 IRANIAN anh 0 gt 113900 0 gt 113900 0 5113800 0 5113780 0 gt 113760 0 gt 113680 0 gt 113580 0 gt 113500 0 51134800 S113460 0 51134200 3113300 0 3113300 0 51132200 5113180 0 2113105 mon sample 0 ALO 640 0 257 0 265 0 281 0 246 0 406 0 347 0 583 0 189 0 291 0 396 0 504 0 326 0 332 0 RAR M Logs Errors 0 Warnings 0 Infos Z a E fr 10 55 55 AM CET Figure 8 9 Example of a point database query in SQuirreL The query that was written to file in JGrass is the one shown in figure 8 11 It extracts data from the east north elevation and sample fields for points with zinc concentration values at the ground sample field greater than 500 120 8 Environmental Databases File Drivers XK Allases Po amp Objects SOL select east north from datizinco select east north from datizinco Plugins Session Windows Help Fo EE ql select from qd select east nor select east nonth from datizinco Results y M etaData Info y 163 9340 0 163 9920 0 163 9680 0 1639360 0 16369650 0 1640060 0 162 9280 0 169280 0 16400600 16390490 0 1639240 0 16391000 1639750 0 1639850 0 1635880 0 1629160 0
72. average equal to about 200 metres for the entire Italian territory 6 3 Importing Raster Data Once you have created a workspace with the right reference system it is indispensable to import the data that you wish to process You can start either from raster maps or vector maps 6 3 1 Importing Raster Maps To import a raster map there are different possibilities according to the format of the map that you want to import to JGrass 1 use the r in ascii command 2 use the r in lidar command 3 use the r in edal command 4 copy the file to one of the JGrass directories The r in asci Command With the r in ascii command 5 it is possible to import ASCII files in the characteristic GRASS format or in the ESRI GRID format The graphic interface for the command is shown in figure 6 13 it contains It is sufficient to copy the file from outside of JGrass to the mapset directory with the name corresponding to the file format if this is supported In this way the map becomes accessible for processing 97 6 Creation of a New Workspace 0 Oe r in ascii ascii file to import grass or arcinfo grid 9 Ttlanginec dtm_flanginec_10 asc browse numeric value to convert to null while importing only for grass map format grass name of the new F imported map der Trentino ARES SSS Fa 7 ok Ll cancel Figure 6 13 The r in asci graphic interface in JGrass e the pathname for the file to be
73. cal analyses car ried out with the Horton operations within JGrass are stored This directory does not store maps only the files created by some of the Horton processes 5 jgrassgroup directory with the definitions of the mapgroups to be used for vertical queries created with the group create command The section relative to groups is still in development and therefore not completely exploitable yet 6 site_lists directory with the sites that is the point maps 7 sql directory with data for database connection via sql 8 some files that contain very important information e DEFAULT_WIND contains the parameters of the default region e MYNAME contains the name of the starting location PROJ_INFO contains information about all the geographic projections of the data PROJ_UNITS contains the units of measurement used in the projections e WIND contains the parameters of the active data region 26 3 Installation As you will have noticed the structure with which data are saved is quite complicated however you will rarely have to deal with it directly If you access the data through JGrass there will be no problems as the program knows where to access and save the required data The only times in which the user accesses the data structure directly is in the case of JGrass directories used for particular data formats in order to speed up the import and export processes as described above To save data in these directories
74. ctive and non interactive yet and the check result commands have not yet been tried The following paragraph gives the complete list of GRASS commands with a general explanation for each command The testing and checking stage is not http www gdf hannover de media php id 7 amp lg en 131 9 Use of the Console yet complete and so this list as of yet exists only in English These commands are surely all active for users of JGrass under Linux e MacOsX while some could be missing for Windows users in particular those for the analysis of satellite data identified with the letter 7 To check if the com mand is available under Windows you only need to search for the executable in the grasscommands directory in the JGrass installation directory 9 4 Index of GRASS Commands The following index is a complete list of all GRASS commands An up to date list can be found at the official GRASS GIS website at under the section manuals g commands Command Description S ACCESS g ask Prompts the user for the names of GRASS data base files g COpy Copies available data files in the user s current mapset search path and location to the appropriate element directories under the user s current mapset g filename Prints GRASS data base file names e findfile Searches for GRASS data base files and sets variables for the shell g gisenv Outputs the user s current GRASS variable settings glist Lists available GRASS data base file
75. d other rights are in no way affected by the above This is a human readable summary of the Legal Code the full license that can be consulted at http creativecommons org licenses by nd 2 5 legalcode Contents 1 Introduction al Eh Grass GIS 10 e a dd aa A amp ee a a de a 12 Future Developments e soe es a e G b oe a a ko Era MOFA CIO sio El e e A E UA ew e 2 An introduction to GIS 2M INtrOAUCION lt a ias rs do 21 Penton 2450 ADAN aa A E A ack ae BS 2 2 Data Model 2 4 5 44 45 AAA A Aa SS EGS 2 3 Types of Geographic Data 4444 64462 os SAREE Aw EAD AAS Be we ZA FUMCHOMA 4 4 8 AAA AAA A De a IIA 3 Installation 3 1 System Requirements vasta a ee EO EA eee eR REO eS 02 Orware Installati l ec e as a A a eh we ee Ol Jar Bue lastallabi m semg h amp A a ca 222 ne Inistalllation Process e o amp a A Be es ca oso EV eiia POSTAS ata E AE ete a ee SS ee A ooo The kh Packages Used aeiia do bod we eG Pee Sete a SA amp er 3 4 Structure of the Installation Directories 0 2 00 eee ee ee oro os ak he we a ETT E he ee Ga a A 4 First Start Up of the Program A HGP OCUCEIOMG er Gk Se hh Rs a dd ods Be bs Be Bok eo ee ee e 42 The Graphic MnGeriace sos d ah 4 04 a A OO AA a Fe Ae ak AGES TODA o oe ge Bo A ee Be es es A ae ee o SS sa CONTENTS AQ Phe Mam Meni a2 6 4 aod bol be o A a A AA 31 A23 The Workspace s s a 25 ew haw ew Wa e o a e de A 31 AZA Ti
76. d the existing colormap should this exist by clicking the load original colormap button If a message appears stating that no colormap was found you can proceed by clicking ok otherwise the colormap will be loaded and displayed in the left part of the screen In the example no colormap was found for the elevation dem map nothing changes in the window and you can proceed to create the colormap that you like To create a colormap for a map you must click on the add rule button until you have a sufficient number subranges for the data in the example shown in figure 5 36 it was decided to divide the data into four intervals It is now necessary to fill the blank text boxes with the highest and lowest value of the data subrange and assign a starting and a finishing colour to the interval To load the colours first Under Windows it is possible to remove a map only if has not been viewed during the current work session due to management problems concerning access to the files in use by the system Therefore if you wish to remove a map that has been viewed in the current work session you will first have to restart JGrass and then proceed with the removal For an as of yet unknown reason you have to select the map name twice in order to view the range of variation of the map data 714 5 First Steps with JGrass 408 choose mapset PERMANENT choose map elevation d gt Hs8 RGB ____ activate sta
77. data saved in point triplets format corre sponding to the x y z coordinates to JGrass The name of the command comes from the fact the data from altimetric laser surveys are often given in this format Of course you can also import data from other software applications or from other types of surveys as long as you maintain this format The graphic interface for the command is shown in figure 6 17 The information it asks for is 1 the name of the file to be imported 2 the specification whether the data are on a regular data grid or irregularly dispersed over an area 3 the name of the new map 4 the specification whether to import only the data corresponding to the active data region or all the data on the file operation that in most cases requires a lot of time 5 the specification of what to do with duplicated points whether to take the maximum the minimum or a mean of the values relative to a single point this is to decide whether to 100 6 Creation of a New Workspace consider the vegetation or the ground if necessary This are no duplicated points in the map r 00 f r in lidar option is not considered if there parameters lidar file to import triplets are on irregular data grid interpolation O triplets are on regular data grid DSM DTM map format grass name of the new imported map z X M import only data fitting the datamask import the whole da
78. dinates that define the perimeter of the closed figure By means of the x y coordinates it is possible to represent points lines and polygons as lists of coordinates rather than as drawings In most cases the storage of elements is done with coordinates from the real world these coordinates represent a real location on the surface of the Earth using one of the many coordinate systems In digital maps the relationship between geographic elements is expressed by means of topology The characteristics of the geographic elements are stored on the computer in a file usually called a table as a series of numbers and letters F Field In a table of attributes it indicates the part of a record dedicated to a single characteristic of the single elements of the table G Gauss Boaga It is a coordinate system based on an inverse cylindrical projection it is typically used for the cartographic cover of Italy IGMI Maps Land Registry Maps Regional Technical Maps etc Geographic database A database dedicated to land and territorial information Georeferencing Computer procedure used to position vectorial and raster data in a real terri 2 An Introduction to GIS torial area according to a specific coordinate system by means of points with known coordinates control points points GIS Geographical Information System A complex set of hardware software and human and intellectual components used to acquire proce
79. duce the console e command to display all the execution information of the commands 9 Use of the Console When the term JGrass appears in the console it means that it is possible to give a new command otherwise the console is busy and you will have to wait the end of the execution of the previous command before typing a new one If you want to execute a command from the console you need to know even just indicatively the name of the command to execute Even in the JGrass console commands can be completed automatically after typing the first few characters of the command name and hitting the tab key For example if you want to execute the d rast command you only need to type the the first two characters and then hit tab once to view a list of JGrass commands that start with the typed characters Obviously the more letters you type and the shorter the commands list will be To execute a command from the console you need to input all the command parameters those that are normally input with the graphic interface preceded by a string that defines it To know what must be typed at the console in order to execute the command you only need to type the command name followed by the string usage For example for the h slope command you should type JGrass h slope usage hit enter Usage h slope quiet verbose version usage pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt flow lt fl
80. e Italy zone 1 and Italy zone 2 depending on the zone to use if the longitude of the reference meridian is referred to the Greenwich meridian In this case the longitude of the reference meridian is 12 degrees 27 minutes 8 4 seconds The longitude of the central meridian of zone West or zone 1 is 9 degrees while for zone East or zone 2 it is 15 degrees e Monte Mario Italy zone 1 and Monte Mario Italy zone 2 depending on the zone to use if the longitude of the reference meridian is set to O degrees The longitude of the central meridian of zone West or zone 1 is 3 degrees 27 minutes 8 399 seconds while for zone East or zone 2 it is 2 degrees 32 minutes 51 6 seconds The precise wording and the corresponding codes for the Gauss Boaga on Rome 1940 carto graphic projection and reference system used in Italy are now listed 3003 Monte Mario Italy zone 1 3004 Monte Mario Italy zone 2 26591 Monte Mario Rome Italy zone 1 95 6 Creation of a New Workspace 26592 Monte Mario Rome Italy zone 2 Should it be necessary to work with geographic coordinates and A referring to the reference ellipsoid rather than cartographic coordinates N and E it is still possible to specify only the reference ellipsoid and its orientation Datum In this case the EPSG code to create a location with geographic coordinates referred to the Rome 1940 reference system is 4806 Monte Mario
81. e Monitor Toolbars 33 q dis 6h aoe rt A A He SH 39 Aa The Menmi Bar saaw dd A ad a OR ee Bee at 39 AS CUSTOMIZACI N saei a a a ad oS DY 43 AA Display Properties 32 e cmime amp rai dl a da a ee Pe oe A bee eS A7 5 First Steps with JGrass 49 5 1 The Spearfish Test Data Set so bss ta al a cd amp a as Ss 49 Hz Recon Param lors 22 eva dl a EN eee dr e a ido AS AQ 9 2 1 Interactive TESION tool s 4 44 oe Suna bh amp oA ee et a Pe eee g 50 Bro VINS SDa de ite ate Rd ee Be ew ee 52 IA RSE Das amp IE EN a E e aara ie 52 oe Vector Dilay sesto ea A A o al Ee ee ed 59 S as O AA NN 64 DAL Querying Raster Maps messi ds e rd a Be ee E es 64 54 2 Querying Vector Maps 1 2406 4 e wood w a Se ae AS A A OH ES 65 oo Plotting Map Pronmles acs pias e EEE SUE A 66 evo Handling Rastor Map a a ecb aegse se paa e caba o a a 69 DOL Copy MOD Lo e E a he ea de as a dle es ee 69 0 0 2 Rane a MAp cis a ot oe Aa S e DE ES 12 OOo ICMOVNe a Map os 2084 o a E 13 5 7 Creating a Colormap for a Raster Map 74 5 8 Calculations with Raster Maps 78 59 Creating a Category Tables s s lt sinemi dad a de GSR OS 80 5 10 Editing Raster Map Values 6 1420 4 ta 6 ae ai e 83 5 10 1 Editing Raster Maps Manually 83 5 10 2 Editing Raster Maps with the Use of Polygons 84 6 Creation of a New Workspace 87 Gal Crean ora LOCO 175 4 4 2 i Hee ene da a he ge Bey a he ee ee SD 87 OL L ading an Existi
82. e for the database connection The information in the connection file is substantially the same as that used for the connection from SQuirreL with the typical syntax of the xml language The file must have e the name of the dataset username password the type of driver used for the JDBC connection the database URL the same as the one used in SQirreL e the information fields to read the column name the data type stored in the column e the data query to extract data from the database An example of a sql file to connect to the flanginec database is shown in figure 8 8 obviously the specifications can vary according to specific circumstances in particular if you interface with the flanginec database the data will remain the same but you will have to specify the correct URL for the database Fie Edit Project Document View Bookmarks Toob Settings Window Help Ld E H eHe garrvhifa lt fields gt lt fields gt lt dataquery gt lt dataquery gt lt dataset gt Y e D E 3 8 o J Y D o E E oo E 2 17 gt 7 a iL SOOOOSOourl j dbc postgresql lt field name lt field name lt field name lt field name lt dataset name zinco description concentrazione di zinco misurata gt lt database driver org postgresql Driver 192 168 31 2 5432 flanginec user moovida password gt east type float gt north type float gt
83. e is shown in figure 7 1 F pa e06 parameters r dem2contour map format grass Input raster map dam Trentino Browse Output folder ica grassdata gauss_boada_ovest browse Output file layer name flangi_ contour Contour step 20 shapefile Output file format dxf ok cancel stop Figure 7 1 The r dem2contour graphic interface in JGrass The parameters to be inserted are 1 name of the input raster map from which to create the contour lines 2 name of the destination directory where the output file in shapefile format is to be saved 3 name of the output file 4 the contour line stept 5 output file format shapefile or dxf Even here the command processing is carried out within the graphic interface you can interrupt the program at any time or at the end of the operation scroll through the output messages The contour line step must be greater than the resolution of the input map otherwise you risk forcing contour lines on non real data 7 Special Operations The fact that in some cases there are error messages during the operation does not necessarily compromise the successful result of the program Viewing the output file will result in something similar to figure 7 2 AAO JGRASS Java GRASS Build 200604281059 File View Gis Raster Vector Extra HortonMachine Help 4602 GE BrRQQQQQQgM 255 BO R
84. ed in this manual are proposed here The introduction to Geographic Information Systems that follows makes reference to the article on the topic at the Italian Wikipedia web site the free encyclopedia More information is available at the English version of the same encyclopedia 2 1 Introduction Geographic Information Systems GIS are computer systems which are used for representing displaying and analyzing the characteristics and elements present on the Earth s surface as well as the events that take place there Any object on the the Earth s surface can be georeferenced that is to say its position can be precisely identified on the terrestrial globe This is the fundamental concept that allows every database to be linked to a GIS In this manual the term database means a set of information about an object and its relation with other objects the term georeferenced refers to the position of an object in a space defined by a coordinate system Before carrying on with the study of GIS it is important to state that they do not offer pre packaged solutions for every sort of spatial problem Everything depends on the skill of the user it is in fact the skill of the user that puts together different operations in a particular order or according to some particular scheme in order to obtain the best results 2 1 1 Definitions A Geographic Information System GIS is a computer system capable of acquiring integrat
85. ed as input for i maxlik to generate an unsupervised image classification Prosecution on next side Prosecution Description Fast Fourier Transform FFT for image processing Brovey transform to merge multispectral and high res panchro matic channels Generates statistics for i maxlik from raster map layer Generate statistics for iissmap from raster map layer Creates and edits groups and subgroups of imagery files Hue intensity saturation his to red green blue rgb raster map color transformation function Inverse Fast Fourier Transform ifft for image processing Mosaics up to 4 images and extends colormap creates map mo saic An imagery function that classifies the cell spectral reflectances in imagery data based on the spectral signature information gener ated by either i cluster i class or 1 gensig Calculates Optimum Index Factor table for LANDSAT TM bands 1 5 amp 7 2 ortho photo Principal components analysis pca program for image process ing Rectifies an image by computing a coordinate transformation for each pixel in the image based on the control points Red green blue rgb to hue intensity saturation his raster map color transformation function Performs contextual image classification using sequential maxi mum a posteriori SMAP estimation displays spectral response at user specified locations in images Targets an imagery group to a GRASS location and mapset Tasseled Cap Kauth Thomas transformation
86. ed by simply right clicking in the main JGrass window the green and white one A popup menu appears in which it is possible to toggle certain particulars which are especially useful at the printing stage These particulars are e Map Scale displays the map scale in the main window The scale is not in the classic form e g 1 10000 but rather in graphic form that is to say a reference length is given by which to evaluate the dimensions of the map e North Arrow displays the North arrow in the main window 47 4 First Start Up of the Program GRASS Environment Cluster Console Y lt param name font fontname LucidasansRe Parameter Name _ Parameter Value name fgcolor lt param name histary clipicon paper_clip pl D lt p ny CpIFon peper Clp Pivalue Sw B lt history icon stock_form listbox png fontnar 1 lt param name icon walue console png gt E lt param name cluster activeicon consale jai B lt param name logmessages activeicon cons E lt param name histor icon value GotoLine 1g B lt param name bgrcolor value B3DEB3 gt kparam name fgcolor value 000000 gt E lt param name prompt walue Grass gt 1 lt param name vwisible value false gt Toggle Map Scale Toggle North Arrow Toggle Data Window Toggle legend Auto Refresh Figure 4 24 The Map Display Properties manu e Data Window displays the outer limits of the active region by marking in green defaul
87. ed operator in raster map algebra is the 2f operator With this operator it is At the moment the r mapcalc command allows you to use maps from different mapsets and directories but all the maps used in one single command must come from the same directory except for the output raster 18 5 First Steps with JGrass possible to carry out combined calculations on maps considering only specific values of a map For example it might be necessary to mark the limits of areas with a claysand geological for mation which corresponds to the number eight in the geologia created earlier and then extract their altitudes from the DEM elevation dem To reach this result it is necessary to recopy the geologia map from the grassasciz to geology in the standard format or else copy the elevation dem map to the grassasci format In this example we will use both maps in standard format Beware however that in recreating the geology map the original is cancelled and therefore so is its colormap the visualization of the map will be different from the initial one The command that will allow you to carry out the operation that has been just described is r mapcalc This tool borrowed from GRASS is very powerful and a description of it can be found in the GRASS Tutorial To carry out the desired operation you can use the r mapcalc if operator For the proper synatax it is sufficient to click the if button of the graphic interface a
88. een created in the Spearfish location To view these data in the dialog box shown in figure 5 12 you will have to select the path to the JGrass installation directory and then select spearfish PERMANENT shapefiles the available shapefiles are here oki al Scie 4 bugsites shp 4 cutstreams shp 4 roads shp K rstrcoishp 4 streams shp File Name Files of Type Shapefile 7 Figure 5 12 Dialog box for the selection of a shapefile to be displayed with JGrass Display Properties Repeating the above procedure in order to display the roads and streams shapefiles you will see that the two maps are displayed as shown in figure 5 13 the default display does not distinguish between the two data types To distinguish between roads and streams you have to change the display setting of one or both of the maps This is done in the same way as is done with raster maps Paragraph 5 3 1 by right clicking on the name of the map in the legend section of the screen There are three active options for vector data 1 Remove map name to remove the map from the JGrass display this option does not jeopardize the hard copy of the file as was seen with raster data 2 View data to view the entire data table associated to the vector map 3 Proprieties to modify the map display properties 99 5 First Steps with JGrass 000 JGRASS Java GRASS Build 200604281059 File View Gis Raster Vector Extra HortonMachine
89. egion boundary parameters with simple graphic operations using the mouse rather than having to insert the data manually in the dialog boxes of the interface shown in figure 5 1 The toolbar that appears on screen by selecting this option is shown in figure 5 2 50 5 First Steps with JGrass Figure 5 2 The Interactive Region Tool toolbar During this stage you can select the boundaries to modify and select the new desired position by clicking on the screen you can select an area that you want as active region fifth button from the left you can move the active window to a new desired position and you can set the map resolution Warning this toolbar must be closed by clicking on the red x button on the upper right hand side once the boundary limits have been set and by all means before carrying out any other operation in JGrass Keeping the toolbar open could cause problems with the following operations because of the superimposition of different types of processes ol 5 First Steps with JGrass 5 3 Viewing the Data The data in Spearfish can be viewed with the aid of the map display toolbar 5 3 1 Raster Data The first panel gives you the possibility to choose the data type you want to display The dropdown By clicking on the icon the Raster Map Wizard for the viewing of raster maps is launched menu lists the different display options see figure 5 3 aoe meee Choose Raster Map Wizard
90. egment v select v surf idw v surf rst v to db v to points v to rast v transform v type v univar v vol rst v voronol v what rast Prosecution Description Random location perturbations of GRASS sites Allows projection conversion of vector files indices for quadrat counts of sites lists Randomly generate a GRASS vector points map Changes vector category values for an existing vector map accord ing to results of SQL queries or a value in attribute table column Sample a raster file at site locations Create points segments from input lines and positions read from stdin in format Select features from ainput by features from binput Surface interpolation from sites data by Inverse Distance Squared Weighting Interpolation and topographic analysis from given point or contour data in vector format to GRASS floating point raster format using regularized spline with tension Load values from vector to database In uploaded printed cate gory values 1 is used for no category and null if category cannot be found or multiple categories were found Create points along input lines Converts a binary GRASS vector map layer into a GRASS raster map layer Transforms an vector map layer from one coordinate system into another coordinate system Change the type of geometry elements Calculates univariate statistics for attribute Variance and stan dard deviation is calculated only for points Interpolates
91. electing the first item of the dropdown menu Map Display Tools see figure 4 7 a new tool bar appears JGR le RIGIS Gis Raster Vector Extra HortonMachine Help 3 Map Display Tools a a Q Q a el Q T Display a raster map Display a vector map Display a site map d Display Postgis layer fe Clears the map display list Rebuild map image at current zoom Figure 4 7 The View menu options as in figure 4 8 Figure 4 8 The Map Display Toolbar The tools contained in the toolbar are view a raster map by choosing one from the list of workspace maps view vector maps available in shapefile format stored in any directory they do not need to be moved to the workspace view a point map in native GRASS5 format as a site map these maps are the ones found in the site_lists directory introduced in Paragraph 3 5 e LE view a vector map from a PostgreSQL remote database clear the screen eliminating all displayed maps 36 4 First Start Up of the Program e 2 redraw rebuild all displayed maps This button is very useful because there are often superimposition problems when various maps are displayed Should you become aware of such problems you only have to click on the redraw button in order to solve them GIS 606 JGRASS File View Raster Vector Extra HortonMachine Help E Ammi A A A AA A A A A Region Manager L Interactive Region Tool
92. els where the original map is selected are the same see figures 5 25 and 5 26 In this example however the newly created esposizione map is selected and renamed esposizione_new in the esriasciigrid directory The r rename command actually moves the map to the place of the new map specified in the following panel see figures 5 30 and 5 31 and removes the original map as opposed to the r copy command that keeps the original map At the end of the procedure if all went well a message appears see figure 5 32 006 Copy Raster Map Wizard fluidturtleascii Y grass H grassascii grassbyrow esriasciigrid lt Prev Next gt Cancel Figure 5 30 Third panel of the JGrass rename raster map wizard OOO ChooseNewMapWizard lA Location spearfish PERMANENT esposizione_new PERMANENT lt Prev Finish Cancel Figure 5 31 Last panel of the JGrass rename raster map wizard 12 5 First Steps with JGrass Boo Message aspect moved successfully to esposizione_new u Figure 5 32 Closing message of the JGrass copy raster map wizard 5 6 3 Removing a Map To remove a map from the file system so that it is no longer available for processing and so E l free space on the disk the command to use is r remove i which launches the graphic interface shown in figure 5 33 r a 606 Remove Raster Map Wizard E M Location spearfish E PERMANENT dem elevation dern esposizione_new
93. emented such as addition and multiplication division but more complex operations such as the trigonometric ones have also been included Furthermore an algorithm has been implemented to introduce calculation cycles in order to do calculations with various maps MA r profile to plot the profiles of a raster map e r colors to create modify or remove the colomap of a raster map e E r cats to create modify or remove the data categories of a raster map r correct to modify a raster map by editing the values of single pixels 39 4 First Start Up of the Program r correctpolygon to modify a raster map by drawing a polygon within which to change the values of the map F r dem2contour to create a contour map vector from a DEM raster ES d what rast to query a raster map J i e r remove to remove a raster map r rename to rename a raster map O En 14 EN r copy to copy a raster map to the same mapset to other mapsets or to other direc torles As has already been mentioned in previous chapter an important aspect of the r copy command is that you can copy raster maps to directories other than the standard JGrass directories In this way you can export maps directly with this command without having to resort to specific export commands In particular within the workspace directory created by JGrass there are other directories as described in Paragraph 3 5 called esri
94. ented Maps are defined as having a big scale 1 500 1 1000 1 2000 an medium scale 1 5000 1 10000 and a small scale from 1 25000 on SIT Sistema Informativo Territoriale Italian acronym corresponding to the English GIS Spatial Data Geometric data characterized by a geographic reference SPOT Systeme Probatoire d Observation de la Terre A family of multispectral satellites with mobile sighting systems used for remote sensing The resolution of the Earth is 20 metres for the multispectral satellites and 10 metres for the panchromatic ones The first launch of this French system dates back to 1986 T 12 2 An Introduction to GIS Thematic Map Representation of a vectorial or raster map in which points lines and surfaces are associated to symbols hatches and colours that represent the results of a quality analysis land use areas of the land use plan traffic intensity on a road etc Topology set of rules by which to define in an explicit manner the relationship connection and contiguity between spatial elements and to associate these elements to their relative descriptions attributes In a topological data model for example it is possible to identify the contiguous areas and to identify the lines that confine each area boundaries y Vector It is graphic data archiving system in which the objects are stored on the basis of the cartesian coordinates of the points and lines that
95. environment engine JGrass may present display problems for certain combinations of operating system and graphics card when the main graphics engine that is to say OpenGL is not optimized 46 4 First Start Up of the Program A aaa Sreferer GRASS Environment Monitor Cluster Console lt param Name Useottscreenbutt Parameter Mare Parameter Value name useoffscreenbuffer a lt param name fontname value Pualue true Cy lt param name fontsize yalue 1 ij lt map window name gcolor wal 1 lt map_ window name Hbgcolor wa Cy lt map_ window name bgaloha w 1 lt map_ window name cursordisp a lt Mmap_ window name cursordisp B lt data_window label Data Mask 1 lt Status_panel name backgroun 1 lt status_panel name foreground B lt status_panel narme bordercolo B lt legend window name icon wal B lt legend_window name Hbgcolor B lt legend_window name bdimage Figure 4 22 The Monitor configuration panel window If there are display problems you can pass from the OpenGL based display to the Java2D display slightly slower This change can be carried out by simply writing false in correspondence of Value in the Useoffscreenbuffer section as shown in figure 4 22 Console As shown in figure 4 23 in this section you can modify the console configurations the font the colour of the text and the background and the command prompt mode 4 4 Display Properties Some map display properties can be defin
96. er defined grid Makes each cell value a function of the attribute values assigned to the vector points or centroids around it and stores new cell values in an output raster map layer Allocate subnets for nearest centres direction from centre Cen tre node must be opened costs gt 0 Costs of centre node are used in calculation Network maintenance Split net to bands between cost isolines direction from centre Centre node must be opened costs gt 0 Costs of centre node are used in calculation Find shortest path on vector network Reads start end pointsfrom standard input in 2 possible formats Create a cycle connecting given nodes Traveling salesman prob lem Note that TSP is NP hard heuristic algorithm is used by this module and created cycle may be sub optimal Create Steiner tree for the network and given terminals Note that Minimum Steiner Tree problem is NP hard and heuristic algorithm is used in this module so the result may be sub optimal tests for normality for points Convert a GRASS binary vector map to a GRASS ASCII vector map Exports GRASS vector files to DXF file format Convert to OGR format Convert to POV Ray format GRASS x y z gt POV Ray x z y Overlay 2 vector maps Creates a new binary vector map layer by combining other binary vector map layers Prosecution on next side 141 9 Use of the Console Command v perturb V pro v qcount v random v reclass v sample v s
97. fic R procedures which vary from operating system to operating system The packages used are e akima it contains the algorithms necessary for the interpolation of spatial data that are distributed irregularly e GRASS the interface between GRASS 5 0 and R e gridBase integrates the graphics creation features e gstat geostatistical forecasting and simulation models e sgeostat An object orientated Framework work environment for geostatistical modelling e VR in some of the newer versions of R this package is included in the basic version union of some of the packages of the basic R version such as MASS class nnet spatial Shttp stats math uni augsburg de Rserve These packages can be downloaded from the web site http cran r project org in the section Contributed ez tension packages OWww r project org look in the Manuals section for the R Installation and Administration Manual The installation of the various packages is explained in chapter 6 for all three operating systems 22 3 Installation 3 4 Structure of the Installation Directories Once JGrass has been installed the directory JGrass will be created in a position selected by the user This directory will contain all the files and executables necessary for a proper functioning of the program The directories that are created are e etc it contains all the graphic interface configuration files and JGrass user profiles e jars it cont
98. for LANDSAT TM data 1 vpoints Zero crossing edge detection raster function for image process ing 133 9 Use of the Console p commands Command Description module to output GRASS data in the format of Virtual Reality p out vrml Modeling Language VRML pg commands Command Description pg postgisdb pg postgisdb photo commands Command Description photo 2image photo 2image photo 2target photo 2target photo camera photo init photo init photo rectify photo rectify ps commands Command Description ps map Hardcopy PostScript map output utility 134 9 Use of the Console r commands Command r average r basins fill r bilinear r blend r buffer r cats r circle r clump r coin r colors r composite r compress r contour r cost Description Finds the average of values in a cover map within areas assigned the same category value in a user specified base map Generates a raster map layer showing watershed subbasins Bilinear interpolation utility for raster map layers Blends color components of 2 raster maps by a given first map Creates a raster map layer showing buffer zones surrounding cells that contain non NULL category values Prints category values and labels associated with user specified raster map layers Creates a raster map containing concentric rings around a given point Recategorizes data in a raster map layer by grouping cells that form physical
99. from a given elevation layer Fills no data areas in raster maps using v surf rst splines interpo lation Construction of slope curves flowlines flowpath lengths and flowline densities upslope areas from a raster digital elevation model DEM Generates a raster map layer with contiguous areas grown by one cell Generates red green and blue raster map layers combining hue in tensity and saturation his values from user specified input raster map layers Convert an ESRI ARC INFO ascii raster file GRID into a bi nary raster map layer Convert an ASCII raster text file into a binary raster map layer Import a binary raster file into a GRASS raster map layer Import GDAL supported raster file into a binary raster map layer Imports GRIDATB FOR map file TOPMODEL into GRASS raster map Import a binary MAT File v4 to a GRASS raster Create raster maps from ascii polygon line data files in the current directory Import SRTM90 HGT files into GRASS Outputs basic information about a user specified raster map layer Calculate error matrix and kappa parameter for accuracy assess ment of classification result r le setup Line of sight raster analysis program r mapcale r mapcalculator Calculates new raster map from r mapcalc ex pression Finds the median of values in a cover map within areas assigned the same category value in a user specified base map Raster file matrix filter Prosecution on next side 136 9
100. geology lt Prev Next gt Cancel Figure 5 33 First panel of the JGrass remove raster map wizard 000 Select an Option Do you really want to remove the choosen maps geology PERMANENT ml al 7 Cancel No Yes Figure 5 34 Dialog box for the removal of a map from the filesystem in JGrass At the moment the removal of maps is only possible for maps saved in GRASS JGrass format If you want to remove the geology map select it from the list and then click Next and Finish to proceed with the operation Before removing the the map you are asked to confirm your choice by 13 5 First Steps with JGrass means of a dialog box like the one shown in 5 34 5 7 Creating a Colormap for a Raster Map The raster maps that do not have a colormap associated are displayed with a standard colour scheme that divides the range of values of the map into five subranges which are then assigned colours e first range e second range e third range e fourth range e fifth range The colormaps are found in the colr directory of the mapset of the map of interest To create or edit a map s colormap use the r colors command ol The graphic interface of the command is shown in figure 5 35 Here it is possible to select as in the previous examples the mapset and the map for colour editing For the map used in the example elevation dem the range of values is 1066 1840m asl The first thing to do at this point is to loa
101. gram is guaranteed only with Java Virtual Machine 1 5 and later versions This does not mean that the program does not run with previous versions of Java but there may be some modules and functions that do not run perfectly If the installed Java version is not the one required by JGrass a warning like the one in figure 4 1 will appear In the specific case shown the installed version is Java 1 5 0_04 while the required version is Java 1 5 0_05 The user is given the choice either to proceed to launch the program or to temporarily 4 First Start Up of the Program shutdown the procedure and install the required Java version which can be downloaded from http java sun com j2se 1 5 0 download jsp Tf as in the case shown in figure 4 1 the installed version is a Java 1 5 you can proceed with the launching of JGrass2 0 as no disfunctions will arise All you need to do is click on the OK button and the program will launch Java version 1 5 0_05 or higher required Found java 1 5 0_04 instead Please ugrade your java Runtime Environment installation fttp waa Java com Continue at your own risk Figure 4 1 The JGrass warning message for the installed Java version check At this point you will have the basic JGrass interface on your screen Figure 4 2 File Help 14 18 0 Free working memory 498MB Figure 4 2 The JGrass graphic interface at its first start up with the basic toolbar 4 2 The Grap
102. have been confirmed it is possible to view the database structure If at the first access the complete structure does not appear see figure 8 5 just select refresh from the popup menu that appears by right clicking on the database name It is not possible at this time to look into the database structure and all the connected infor mation with great detail despite the fact that it is a very simple database insomuch that it is a point database The only information that is strictly necessary in order to understand the data is that which is found in the public TABLE directory Under each one of the tabs of the tables present in the example there is only the datizinco table you can find different types of information about the data The most important information is under the Columns and Content tabs Data referring to zinc concentrations measured at the ground and found in the datzzinco table are shown in figures 8 6 and 8 7 116 8 Environmental Databases 3 ao x gt CHE Y gt AP Objects SOL EA schema Row IDs Versions ll pg catalog Info Content Row Count Columns Primary Key Exported Keys Imported Keys Indexes Privileges Column Privileges 5 public Po Propenyname ae _________ H INDEX catalogName AA H O SEQUENCE childTables lt null gt H O SYSTEM INDEX qualifiedName public datizinco GB SYSTEM TABLE remarks lt null gt G SYSTEM TOAST INDEX schemaName public G SYSTEM TOAST TA
103. he files contained in the locations and mapsets is done by JGrass All the operations that require the direct manipulation of the internal data structure 24 3 Installation should always be done with JGrass only the advanced user should try to manually change the filesystem files directly but it remains unadvisable to do so under most circumstances A layout of database use in JGrass is shown in figure 3 7 all the items shown correspond to filesystem directories DATABASE C Documents and Settings jgrassdb LOCATIONS lat_long gauss_boag a_ovest UTM_WGS84 MAPSETS PERMANENT PERMANENT PERMANENT coordinate flanginec tibet stazioni_meteo rio_gola north_italy Figure 3 7 Layout of the data structure used by JGrass In order to understand the JGrass data structure it is important to know that all the maps except the sites are saved in a series of separate files that contain the data the categories the map limits the resolution and other information The directories that are created in a JGrass location are the following here we give a brief description for further details please consult the GRASS web site or the book Open Source GIS a GRASS Approach 1 directories for raster data management in each one of these directories there are files with particular information corresponding to maps created in JGrass e cats contains the files with the category specifications created for the maps e cell and all the d
104. he maps present in the input location or not e the choice to optimize the cutting of the map to the limits of the active data region or not 107 6 Creation of a New Workspace The tool presents itself as shown in figure 6 25 where the dem map is being re projected to a new reference system 0606 r proj Mapset of input map erica grassdata gbovest Trentino Input map Output raster map Resolution of output map fe nearest bilinear Interpolation method to use cubic C List raster files in input location and exit Do not perform region cropping optimization Figure 6 25 The r proj graphic interface in JGrass Once the operation is complete it will be possible to view the dem map and continue with other operations in both the Gauss Boaga zone West location and the UTM WGS 84 location indifferently 108 7 Special Operations In this paragraph some useful solutions for raster and vector map processing will be presented These solutions have been prepackaged for the user but they are not necessarily the only path to the required solution 7 1 Creating Contour Lines from a DEM To carry out a geomorphological analysis a DEM in raster format is required However it is often necessary to export the data for graphic processing with other applications it is therefore useful to have a contour lines file created from the DEM data The tool to use in this case is r dem2contour its graphic interfac
105. he real data Se si vuole procedere con linterpolazione Kriging i 2 e prego inserire il nome della nuova mappa krige Figure 10 17 Message window asking to continue the interpolation procedure and create an interpolated map from the point map The same procedure can be repeated with the exponential model inputting different parameter values on the basis of the diagram of figure 10 18 In this specific case the difference between the two models is not marked but in most cases one model represents the data better than the other 153 10 Statistical Processing Varlogram estimator logmaas estvar 0 6 partial sill cs ce cg 0 4 a2 Classical semi variogram estimator sill c0 08 0 0 a 500 1000 1500 lag range as 3 ae sqrii3 ag Figure 10 18 Schematic diagram for the estimate of the coefficients to input in the semivariogram model By inputting the output map name and confirming with ok the actual interpolation process begins There are two output maps one of the interpolated values on a regular grid and the other with an estimate of the error also referred to the regular grid The estimate of the error is very useful for the validation of the interpolation process the closer the error value is to the interpolated value the less significant the interpolated value is and therefore the less valid the interpolation is as a whole Of course the estimate of the error
106. hic Interface The JGrass interface shown in figure 4 2 first appears equipped with main menu and toolbar 4 2 1 The Toolbar The initial toolbar has three icons 30 4 First Start Up of the Program E loada previously created workspace a e gt launch the printing dialog box not usable at this stage o launch the manual of commands integrated in JGrass 4 2 2 The Main Menu In the menu bar at the top of the screen is the main menu It is composed of the File and Help menus In the File menu you can find the commands to create and load workspaces and to define the settings of the program In the Preferencessection you can find all the particular and advanced configuration options of the program In the Help menu you can find the HTML reports that describe the JGrass commands divided according to working categories and an About section where there is some useful information about the program the names of the developers the sponsors and the main characteristics of the program If you access the Help menu all the available commands can be reviewed The command classi fication uses the same scheme as used in GRASS e general includes all the GIS general management commands e display includes all the commands necessary for the visualization of maps and graphics environment management e raster includes all the commands necessary for analysis of data in raster format e vector includes all the commands
107. ibility to include JGrass in their start menu Figure 3 6 while for MacOSX users an icon is automatically created in the applications bar One final panel will inform you of the successful installation and will indicate the path to the uninstall file To conclude the installation you will only have to click Done The installation is complete and it is now possible to run JGrass 20 3 Installation Creato con IzPack http www izforge com Seleziona un Program Group per lo shortcut crea shortcut per e questo utente OpenOffice org 1 1 3 OpenOffice org1 1 Settings Settingsmenu ALSI HydroloGI5 JGrass Ristabilisce lv Crea uno shortcut sul desktop S Indietro avanti Esci Figure 3 6 Window with the settings for the JGrass shortcut 3 3 External Programs Two external programs can be linked to JGrass GRASS and R The interconnections with these programs are managed differently according to the operating system used In particular if you use e Windows GRASS since version 1 5 of JGrass it is possible to install the precompiled GRASS applications for Windows If you wish to install them recommended choice it is neces sary to leave as is the selection corresponding to GRASS in the window shown in figure 3 4 and then select the Binaries for Windows package for installation in the following window Figure 3 5 R it is necessary to have the R stati
108. ined If to display the map with new colormap redrawing the map is not enough you will have to remove the map from the display Paragraph 5 3 1 and then redisplay it 5 3 1 76 5 First Steps with JGrass 000 GRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help BkQQQQQQQHM EZS B E Raster Layers M elevation dem M aspect FS Vector Layer Point Layers 1 103208 Easting 597159 Northing 4913920 Elevation 0 IN AAA O Ly Figure 5 39 The elevation dem map with the modified colormap V 5 First Steps with JGrass 5 8 Calculations with Raster Maps The command that allows you to carry out mathematical operations of different sorts on raster maps is the r mapcalc command To carry out operations on a raster means that for every cell of the raster the specified operation is carried out The command syntax is very similar to the one used in GRASS but it has a graphic interface which is very easy to use With r mapcalc you can carry out simple operations such as addition and multiplication of different maps or with values from the same map you can also carry out more complex operations that rely on trigonometric functions The interface of figure 5 40 shows the creation of a new raster prova dem obtained by sub tracting 50m from the elevation dem map All operations on raster maps can be carried out by choosing maps from the various mapsets loaded i
109. ing storing analyzing displaying and mapping information derived from georeferenced data http it wikipedia org wiki Sistema_informativo_territoriale http en wikipedia org wiki GIS 2 An Introduction to GIS 2 1 2 GIS and LIS According to Burrough 1986 a GIS is made up of a series of software tools for the acquisition storage extraction transformation and display of spatial data from the real world It is a computer system able to produce manage and analyse spatial data by linking to each geographic element one or more alphanumeric descriptions GIS can be seen as a type of DBMS Database Management System capable of managing geographical data Although the terms GIS and LIS Land Information System are often used indiscriminately many authors agree that the two definitions do not coincide The term LIS in fact being referred to land is restrictive with respect of the term GIS Mogorovich 1988 defined LIS as The often informal body of people instruments and procedures that allow for the acquisition and distribution of data within the organization environment and that makes them available in the moment in which they are needed to whoever needs them in order to carry out any activity 2 2 Data Model In order to represent data in an information technology system a flexible and representative model must be formalized which adapts well to real phenomena In a GIS there are three types of inform
110. ing data triplets in x y z format 4 o import altimetric laser survey data to JGrass and data triplets in x y z format in general The data can be supplied according to a regular grid or as a series of irregularly distributed points on the land surface In the latter case the data are interpolated by means of JGrass s R connections so as to obtain regular grid model of the land surface ia import all Open Source GDAL supported data to JGrass e re project data from other locations with different reference systems in the reference system of the current location It must be said that re projecting data normally causes a distortion of the image due precisely to the change of reference system www gdal org 38 4 First Start Up of the Program Raster Operations on raster maps Query raster maps Handle raster maps r mapcale y a gt MA r profile r colors H r cats edit E cows y r correct polygon ize r dem2contour Figure 4 12 The Raster menu options This section contains all the basic raster management tools The main functions available see figure 4 12 are for non hydro geomorphological calculations on raster maps and for modifying map properties e g name or mapset The options available in the Raster toolbar are Figure 4 13 The Raster toolbar o r mapcale to do calculations with maps The main mathematical operations that can be used have been impl
111. irectories that have cell as part of their name cell_misc cellhd and fcell they contain all the raster map data e colr contains the raster maps colormaps 2 directories for vector data management these directories are used for the management of vectors in native GRASS format Usually the shapefile standard is used in JGrass which 11 www grass itc 1t 12Neteler Mitasova Edizioni CAP 25 3 Installation does not require a particular data structure in order to be saved to disk e digand all the directories that have dig as part of their name contain the specifications of the vector maps in native GRASS format e dig ASCII contains the vector files in ASCII format which can therefore be consulted directly by the user 3 JGrass directories for the management of particular formats of raster maps e esriasciigrid directory with ESRI ArcView ASCII files here they can be read directly in JGrass and so you can avoid the import procedure e fluidturtleasci directory with Fluidturtle format files swap format for specific applica tions developed by CUDAM in particular the distributed hydrological model GEOtop here they can be read directly inJGrass and so you can avoid the import procedure e grassascit directory with GRASS files in ASCII format here they can be rad directly by JGrass and so you can avoid the import procedure 4 hortonmachine directory in which files resulting from hydro geomorphologi
112. is Use this module to generate naturally looking synthetical elevation models DEM GRASS module to produce a raster map layer of gaussian deviates whose mean and standard deviation can be expressed by the user It uses a gaussian random number generator Surface interpolation utility for raster map layers Produces a raster map layer of uniform random deviates whose range can be expressed by the user Flow computation for massive grids Float version Generate images with textural features from a raster map Thins non zero cells that denote linear features in a raster map layer Print add remove a timestamp for a raster map Converts a raster map into a vector map layer Creates topographic index In a tan beta map from elevation map Simulates TOPMODEL which is physically based hydrologic model Outputs raster map layer values lying along user defined transect line s Calculates univariate statistics from the non null cells of a raster map calculates univariate statistics from a GRASS raster map Watershed basin creation program Watershed basin analysis program Queries raster map layers on their category values and category labels 139 9 Use of the Console r3 commands Command r3 in ascll r3 1n v5d r3 info r3 mapcalc r3 mask r3 mkdspf r3 null r3 out ascil r3 out vod r3 timestamp commands Command v buffer v build all v build v build polylines v category v clean v convert all v convert v
113. is greater the further you are from a measured value At the end of the procedure a message will inform you of the creation of the two maps ony ML La mappa interpolata e quella degli errori sono krige Kkrige err Figure 10 19 Final message of the interpolation procedure with the details of the two maps that were created If the selection of the variogram model were not correct or the parameters chosen were not optimal the display would show either a vertical or a horizontal line figure 10 20 The resulting semivariogram is clearly unusable in the kriging interpolation 154 10 Statistical Processing Variogram of siti_flanginec S a 8 wW w w a a S A 0 A A A A 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 lags B fitted model M estimated lv fitted model y estimated Figure 10 20 Graph with the superimposition of the real semivariogram and one obtained with the exponential model and wrong parameters The two maps will contain valid values in the entire active data region to trim them down to a surface smaller than the active region just use the r mapcalc command Tile View Gis Raster Vector Extra HortonMachine Help Lao BE Qagqgqgagasl moot 10 m Easting 1641467 Northing 5 112273 trentino x pa A fer O Figure 10 21 The point map interpolated by kriging 155 10 Statistical Processing 156 11 Printing Printing h
114. l appear with the following tabs Framework graphic interface management GRASS Environment GRASS connection configuration Monitor display properties management e Cluster This option is not yet active Console JGrass console configuration management 43 4 First Start Up of the Program JEE Framework GRASS Environment Tita ers version Revision 1 22 thloginconfig value login lt authlagincantig value togin car birnestamp 2006 01 81 10 16 B lt helppath value doc help gt 1 lt splash fortname Lucidabansk e E lt clienttype vwalye swing gt Cy lt userprofile value user profile g Cy lt tmpfilepath value gt 1 lt templates walye etc templates Cy lt workspace yallle etc workspal 1 lt quitabpanel closeicon stock_ta E lt Qrassenviranmentwizard step li Cy lt errordialog warningicon errore i lt tipottheday tips tips xml gt lt title walue Grass 2 0 Trento Fi lt icon value jgrasslogo jp Figure 4 19 The initial window of the Preferences configuration panel Framework It is the configuration starting point here it is possible for example to configure the font definitions size and type and the display language used In particular we would like to point out e resourcebundle locale it this indicates that the graphic interface language is Italian it is possible to choose from the languages available in JGrass English en Spanish es German de and Fre
115. l le e e O a File View Gis Raster Vector Extra Mio ER Help Basic topographic attributes Network related measures Hydro geomorphic Indexes and relations Figure 4 17 The HortonMachine menu options The hydro geomorphological processing section contains all the territorial analysis algorithms necessary for delimiting areas that are hydro geomorphologically at risk The options of this menu are not dealt with in detail here for a complete definition of the 42 4 First Start Up of the Program available options you can refer to the HortonMachine Tutorial and The Horton Manual Help File View Gis Raster Vector Extra HortonMachine Mi 180 pagra oe Tip of the day About Figure 4 18 The Help menu options In this section there are the main indications for the commands and some particular references to the developers sponsors and the Open Source JGrass Project participants The contents of the menu already mentioned in Paragraph 4 2 2 are shown in figure 4 18 4 3 Customization The JGrass graphics environment and all the configurations for the connection to external programs are configurable by the user by selecting Preferences from the File menu see figure 4 6 The Preferences option should be only accessed by advanced users and by all means the default settings are valid If you decide to proceed with the customization procedure a window like the one shown in figure 4 19 wil
116. layed each map is assigned a certain transparency factor in order to superimpose as many maps as possible Warning with JGrass2 0 many of the display problems associated with the video card have been solved However if under Windows you should encounter map display problems or should the pro gram shut down during the visualization of a map you will have to reduce the graphics acceleration of the video card Warning in some cases the visualization of new maps can cause an offset of the display to 93 5 First Steps with JGrass 0009 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help BrbQQQQQQQeh so BA vmz658 19m F____ Easting 609107 Northing 4928805 A JO AA Figure 5 5 JGrass view of the elevation map from the Spearfish dataset 0008 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help BkRAQQQQQQH B55 BR L m re Northing 4913464 JGRASS Test Database x O a A YO A Figure 5 6 JGrass view of the elevation and aspect maps from the Spearfish dataset solve this it is sufficient to reload the visualization by clicking on the 3 button and everything will be redrawn and displayed correctly This operation is also necessary every time that you use a particularly different zoom or a particularly different view in order to adjust the display to the data that have actually been loaded It is possible
117. llows a screen panel which informs about the changes made with respect to the previous versions of JGrass It also lists the new features of the current version as well as the known bugs The following screen panel lists some information for the installation of the software in particular situations and with configurations Generally it is not necessary to follow the guidelines proposed The following screen panel Figure 3 4 is the most important of the entire installation proce dure It is divided into three parts 1 Java environment installed an automatic recognition method for the path and version of the installed java runtime environment has been implemented If it should fail and the text box should not show the absolute path to the java environment it will be necessary to insert it N B the logo may be different from the one shown here depending on which version of the software you are installing 4 www gnu org 17 3 Installation 606 IzPack Installation of JGrass 1 Please read the following license agreement carefully GNU GENERAL PUBLIC LICENSE 0 Version 2 June 1991 Copyright C 1989 1991 Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document but changing it is not allowed Preamble The licenses for most software are designed to take away your freedom to share and change it By contr
118. ly discrete areas into unique categories Tabulates the mutual occurrence coincidence of categories for two raster map layers Creates Modifies the color table associated with a raster map layer Combines red green and blue map layers into a single composite map layer Compresses and decompresses raster files Produces a GRASS binary vector map of specified contours from GRASS raster map layer Outputs a raster map layer showing the cumulative cost of mov ing between different geographic locations on an input raster map layer whose cell category values represent cost Prosecution on next side 135 9 Use of the Console Command r covar r Cross r describe r digit r distance r drain r fill dir r fillnulls r flow r grow r his r in arc r 1n ascil r in bin r in gdal r in gridatb r in mat r in poly r 1n srtm r info r kappa r le patch r le pixel r le setup r le trace r los r mapcalc r mapcalculator r median r mfilter Prosecution Description Outputs a covariance correlation matrix for user specified raster map layer s Creates a cross product of the category values from multiple raster map layers Prints terse list of category values found in a raster map layer r digit Locates the closest points between objects in two raster maps Traces a flow through an elevation model on a raster map layer Filters and generates a depressionless elevation map and a flow direction map
119. ment only present in the menu 1s tl Vector map querying allows you to obtain by clicking on the desired object all the information relative to the selected object be this a point a line or a polygon To view the table with all the vector information it is sufficient to right click on the name of the displayed map in the legend part of the screen and select the View data option as shown in figure 4 15 000 JGRASS Java GRASS Build 200604281059 File View Gis Raster Vector Extra HortonMachine Help LEQ SZSRBRQQQQQRAAA oo BO 3 Raster Layers e i i es R rH a lo rH Ms 3 as Vector Layer E Ea X Remove roads te e l A xe e y a a RR a L X Properties o pe Fi E e sx Free working memory 208MB Bs Read feature 825 825 Figure 4 15 Viewing a shapefile in JGrass and the possibility of viewing the contained data 41 4 First Start Up of the Program Extra 008 JC File View Gis AAA Extra ERREF Help 2999048 12 Figure 4 16 The Extra menu options This section holds the Extra tools integrated in JGrass These tools include statistical tools that can be used through the connection with the Open Source statistical analysis software R and graphic display tools What has been integrated so far is shown in figure 4 16 HortonMachine imi sl oin uin in ls cl in bn in i nl ld m
120. minimum value e 25 h percentile e median e mean e 75 h percentile e maximum value e variance 147 10 Statistical Processing Information about siti_fanginec Figure 10 7 The html report of the JGrass g statistics command for the display of the statistical report 10 3 The Probability Density Function The probability density function of the data in the map is by definition a function that ex presses the probability that the value assumed by the casual variable Z falls within the interval defined by z e z dz through the relation P zmin Z min z dz f z dz To plot the function you must check the third option of those given see figure 10 8 148 10 Statistical Processing rparameters roptions _ info about the dataset _ statistical summary about the dataset v plot the probability density _ plot the ecdf and the pnorm _ do geostatistic interpolation map format grass the point ma FF Browse p p siti_flanginec Dworkshop Browse number of rows to use columns to take into account number of steps for pnorm ok cancel Figure 10 8 Graphic interface of the JGrass g statistics command requiring the probability density function to be plotted The result is shown in figure 10 9 Probability Density Plot of siti_flanginec Values frequency E Columni Columni 5 Figure 10 9
121. mmands have a standard JGrass type graphic interface 91 6 Creation of a New Workspace 0 06 Workspace Wizard Select GRASS location mapsets The GRASS workspace stores maps in mapsets the boundaries of which lie within the geographic boundary of the location Select any mapsets to be accessable in the workspace creating them if necessary then click the Next button PERMANENT Y Trentino New Mapset Trentino Figure 6 8 Window for the selection of the mapsets to load in the new workspace The next window asks for the name of the new workspace and a brief description for example you can write what is shown in figure 6 9 0 06 Workspace Wizard Name GRASS workspace The GRASS workspace has been defined and now requires a name and description which will be displayed when selecting which workspace to load Enter a name a short description and select whether the workspace will be available to only this current user or all users then click the Next button Name Trentino Description Gauss Boaga Ovest lt gui class jgrass module grassgui grass icon grassgui icon gt lt param name monitor module Monitor gt lt param gt lt param name console module Console gt lt param gt lt gui gt lt data dbase file Users erica grassdata location gb_ovest des lt mapset name Trentino desc ddd gt lt mapset gt lt data gt lt scripts p
122. n Name Value name Monte Mario Italy zone 1 epsg 3003 proj tmerc lat_O 0 lon_O 9 k 0 999600 x_0 1500000 y 0 0 ellps intl units m towgs84 0 0 0 north 5115000 south 5110000 west 1636000 east 1645000 ns resol 100 ew resol 100 lt Prev Next gt Finish Cancel Figure 6 7 Summary window of the new workspace The next step is the creation of the mapset that is to say the subdirectory in which you will actually work By default the PERMANENT mapset is proposed It is advisable to create a new mapset by writing a name in the text box at the bottom of the window and clicking Create The mapsets that will be loaded in the workspace are the ones that are checked by checking the check box corresponding to the mapset name In JGrass it is possible to save and carry out operations on maps from different mapsets however when you are working with native GRASS commands it is not possible to select the mapset and so reference is made to the default mapset that is to say the first of the list of loaded mapsets It is therefore advisable to use workspaces with only one loaded mapset so as to be able to process data with the native GRASS commands and to turn to multi mapset mode only for transitory operations By native GRASS we mean those commands that are executed in JGrass applying the original GRASS command These operations are carried out unseen by the user as the co
123. n The file must have an xml extension and in particular it must have the name postgis cml The file syntax is the same as that used for the point database connection file but in this case as shown in figure 8 15 it only has database connection information e name of the database name of the database on the server host address e username e password Once the connection file has been created you can start up JGrass and view the data In JGrass the FRIDA workspace created earlier must be loaded To view the data on PostgreSQL Postgis 125 8 Environmental Databases Fie Edit Project Document View Bookmarks Took Settings Window Help LE e2 dHA 9a dQ o dd lt postgisdb gt gdb name osnabrueck databasename osnabrueck host 192 168 31 2 user moovida passo rds Aaa fy lt postgisdb gt Er Fiesystem Browser Projects E Documents Line 4 Gal 1 Sj ns NORM postgis xml 4 Find in Fies Terminal Figure 8 15 Example of the JGrass connection file for the Osnabrueck spatial database hel click the icon in the map display toolbar If the connection configuration file has not been written and saved an error message will appear figure 8 16 giving the pathname and the name of the configuration file required to define the database No postgis database definitions available intile home silli grass grassdata gau
124. n the white area of the screen and the default region the greatest viewable area you must select Region tools and then Region Manager from the GIS menu The dialog box shown in figure 5 1 will appear The upper part of the window refers to the active data region while the lower part refers to the default region 800808 g region parameters Active Data Region Y edit set region from map l extend region with map l calculate active cells north 4930365 0 south 4911345 0 west 589980 0 east 609000 0 nsres 18 57421875 ewres 18 57421875 rows 1024 cols 1024 map selection PERMANENT Browse SS extend region with map x rass 4 __ write the active region to disk default mapset write the default region to disk ok cancel Figure 5 1 The window the current active data region and default region information Assuming that initially the default region does not need to be modified by the user the possibility 5 First Steps with JGrass of editing it is deactivated in order to proceed it is sufficient to check the corresponding edit check box The information contained in the region window are e Set region from map to set the active data region to that of a saved map This option only works if you select a map in the map selection box e Extend region with map to extend the active data region to include a map that is partially or totally
125. n order to use the R server you need to have R installed on the machine 2 01 is supported for Unix Mac and 2 0 for Window Then you need to install the Rserve You can find it in src R To install for Unix Mac R CMD INSTALL path to Rserve_0 3 14 tar gz To install for Windows copy the Rserv exe to the install bin directory which holds the R dll Enjoy The JGrass Team Made with IzPack http www izforge com hi Figure 3 3 The screen panel listing particular installation configurations manually 2 Language in which the program will be installed by inserting the corresponding abbreviation The path to insert is the one to the bin directory which contains the java executable file In Linux and MacOSX the executable is called java while in Windows it is java exe 18 3 Installation 3 Minimum and maximum memory parameters of the memory range for the execution of JGrass These two parameters are important as they define the memory resources that will be ded icated to JGrass Setting these parameters well during the installation taking into account the available RAM will help avoid unpleasant surprises during the execution of the type Out of memory error 4 Interconnections between JGrass and some external programs If the listed programs are not installed on your system just leave the contents of the text boxes unaltered by default there is a point More details abou
126. n that allows you to import maps outside the active data region has been selected the map to be imported is a technical map of an area near the DEM area but does not coincide with it e OA r in gdal raster to be imported JDesktop flanginec 91b04116 tif browse band to select default all location from which to read proj name of new location to create W override projection extend location extends C list formats and exit C keep band numbers instead of using band color na map format grass resultant raster map Figure 6 18 The r in gdal graphic interface in JGrass Once the parameters to be used during the processing phase have been defined all you have to do is click ok to carry out the operation The operation progress is displayed in the graphic interface as an output of the original GRASS command If you realise that there are incorrect data or for some reason you have to interrupt the program all you have to do is click the stop button to terminate the operation before obtaining the final result 102 6 Creation of a New Workspace 00808 r in gdal i ERAN Applications Grass grass61cvs app Contents Reso ERIN gt gt Over riding projection check gt gt Proceeding with import gt gt 2 5 8 11 14 17 20 23 26 29 32 35 38 41 44 47 50 53 56 59 62 65 68 4 71 v Finished cancel stop Figu
127. n the workspace and the accessory directories in the JGrass location The choice of these format and mapset varies the list of available maps which is in the lower left of the window You can choose a map from the dropdown menu any time you need to insert one in the calculation formula It is of utmost importance that you specify the name of the map to be created otherwise an error message will appear asking you to fill the missing entries It is possible to specify the destination for the new map the default option saves the map in GRASS format in the default mapset that is shown beside the map name Clicking ok launches the processing operation that can be more or less slow depending on the size and resolution of the active data region Clicking cancel closes the command without carrying out the operation G 060 r mapcalc parameters Selevation dem 50 l map format gras ooo prova dem OPERMANENT Browse W fier ll V caffe da A fal Japs mon EE elevation dem ES ol ru lt gt bs mod atan 16 ok cancel Figure 5 40 Graphic interface for the raster map algebra command After the processing you can view the newly created map and check if the calculations are correct by running d what rast Paragraph 5 4 1 on the two reference maps elevation dem and prova dem The difference of values in every corresponding point of the two rasters should be 50m A very much us
128. nch fr some items in the French version are still in English because the development is still incomplete if you know French you might like to contribute e template value etc template location of the printing templates defined by the user e workspace value etc workspace location of the workspace settings GRASS Environment In this section the definitions of the connections to the GRASS commands can be viewed As has been explained in Paragraph 3 3 a mechanism has been developed by which it is possible to execute native GRASS commands from within JGrass on all operating systems The contents of this window relative to the Linux and MacOSX systems is shown in figure 4 20 while in a Windows environment the window is like the one shown in figure 4 21 As can be noted the options set during installation can be modified as well as some standard JGrass definitions In particular e gisbase reference path to the GRASS6 0 executable commands Here lies the substantial 44 4 First Start Up of the Program difference between operating systems under Linux or MacOSX where GRASS must be in stalled separately the path to the GRASS installation must be inserted in this box under Windows where the command binaries are supplied it is sufficient to leave the point exactly as explained during the installation phase of the program scriptpath directory where the executable JGrass scripts are to be stored libpa
129. nd All subdirectories and files that define a location are created automatically when you choose to create a new location in JGrass see Paragraph 6 1 Each location contains one or more mapsets which are the directories in which the data are effectively saved The original reason why the concept of mapsets was introduced was to facilitate the multiuser approach to the data For every user that accessed the data there would have been a corresponding mapset The approach was then kept not so much to for the multiuser concept but rather because it is possible to save in different mapsets the data relating to different projects or to calculation subregions From each mapset it is possible to read the maps found in the other mapsets however it is not possible to modify them every modification and elaboration must be saved to the current mapset When a new location is created the PERMANENT mapset is automatically created where the fundamental data of the project can be saved that is to say the data common to all the mapsets of the location Usually data are not used directly from the PERMANENT mapset rather they are copied to the working mapset where they are successively processed The general settings of the location are stored in the PERMANENT mapset in particular the default region definition The boundaries of the active data region are defined in each single mapset along with the working resolution required The organization and management of t
130. nd a string like follows will appear i ne which means if condition action for true condition action for false condition To complete the command string you must click where a value is to be input and then select a map or write a condition action We advise you to always use the if structure even if you are operating on a single map with the null value for external points This is because some functions especially the trigonometric ones do not read the values corresponding to nullas non valid values and they therefore calculate data even for points that are external to the map but inside the active data region the area that usually remains white during map visualization The process of creating a new claysand raster map obtained by isolating points in the geology map and associating the corresponding altitude from the elevation dem map to them is shown in figure 5 41 The resulting map is shown in figure 5 42 where the the original geology map is displayed with a 0 2 transparency factor while the new claysand is displayed with a 0 8 transparency factor http www gdf hannover de media php id 0 amp lg en 19 5 First Steps with JGrass 0 08 r mapcalc parameters map format grass claysand OPERMANENT WSN lg afelol gt if Sgeology 8 elevation dem null 0 La grass mapset al 5 el aa 11 Jar n aele lt gt EBA FE la E UC call EA la
131. need to launch SQuirreL and create a new alias connection The first window of the SQuirreL start up is shown in figure 8 1 ONZZ lt KKKKKKK K K 5S e Es ent Versi n 2 1 final 222222 9 Q Sybase Adaptive Server Anywhere Sybase Adaptive Server Enterprise Q ThinksOL Logs Errors 0 Warnings 0 Infos 7 E a 10 32 48 am CET Figure 8 1 The SQuirreL start up screen The important things to notice are the two windows displayed by the program that contain the list of available and installed drivers on the left and a list of the databases to which you can connect in the centre In the example it is important to check that the PostgreSQL driver has been loaded At this point you can create a new database connection by clicking on the of the aliases table Figure 8 2 The required information when creating a new connection is 1 name of the connection 2 the driver used the type of database to which to connect 3 the URL of the database written with the specific syntax that is suggested at the beginning of the procedure 4 username 5 password All the other required information can be left with its default setting 114 8 Environmental Databases Add Alias Mame flanginec Driver v PostgresGL URL jabc postgresgql 192 168 31 4 54232 fang nec User Marne moovida Password Petter C Auta logon Connect at Startup
132. nel Although we are trying to keep JGrass as much as possible in pure Java some parts are still written in the native language of GRASS by means of Sun s API JNI technology Within the JGrass structure there are a 2D 3D display monitor based on OpenGl technology GL4java Jogl and a console from where it is possible to launch applications and all the original GRASS commands There are also toolbars and a menu bar that can be used instead of the console In this manual a project that makes use raster map visualizations vector files sites and even shapefiles ESRI 2D and 3D visualizations and some printing and exportation utilities will be presented 1 Introduction 1 2 Future Developments JGrass has evolved greatly over the last two years thanks to the experience acquired by the developers and to the interest of a great number of people It can propose itself in the near future as a complete and easy to use GIS for environmental analyses comparable to the better known ArcView The development of a complete vector environment is expected shortly 1t will include vector editing and it could be used as a viewing instrument for remote maps in other words it would be a complete WebGIS for analysis and calculations of maps stored on a central database Another area under development is the possibility of processing large quantities of data LIDAR Laser Scanner surveys are becoming ever more common they allow fo
133. nes to obtain a raster requires a lot of time by all means the operation s progress is displayed in the command window Here it is also possible to check how the process is going and if there are any errors These cannot not be modified during the operation if anything the operation can be interrupted the error fixed and the operation repeated from the beginning When using native GRASS commands it is of utmost importance that the output maps do not exist already If a map exists with the same name as the GRASS process output map the operation will be terminated with an error of the map already exists type Particularly in the case of the v contour2dem various GRASS commands have been incorporated this is why the operation output is such a wealth of information The result of the interpolation is shown in figure 7 4 the original contour lines are also shown in transparency Of course calculations can be carried out on the resulting map to eliminate any inconsistencies or to isolate a part of the region For example the yellow area to the North of the map in figure 7 4 could be removed with the r mapcalc tool by assigning null to the value corresponding to the yellow of the map MMMM t 20 z gt G File View Gis Raster Vector Extra HortonMachine Help EJ 5 xQqaq99904 1 41455 10 m trentino x Easting 1641988 Northing 5 112001 Ready 0 Free working memory 234MB
134. ng Location se cil e a ae es i ee WS ee es 93 6 2 Choice of the Reference System and Cartographic Projection 94 6 0 Importe Raster WA bars ei sce A A ee ae ee ES ee ee 97 6 3 1 Importing Raster Maps ds eS ee RS A A ee 97 CONTENTS 6 3 2 Hmportine Vector Maps porras BG Ook Gk Se A ARA SE 105 0d Mata Re Projections sars dd a we ek Et AI A A ee A Se Ee 105 7 Special Operations 109 7 1 Creating Contour Lines from a DEM 0 0 02 0008 109 1 2 Creating a DEM from Contour Lines e 110 8 Environmental Databases 113 8 1 Installation and Usage of a Database Client 0 0 113 8 1 1 Creation of the Remote Database Connections 114 8 1 2 Connection and Data Visualization ses ae ee 116 8 2 How to Interface JGrass to the Database 118 8 2 1 The Interface for a Point Database 0048 4 118 8 2 2 The Interface for a Spatial Database 0 124 9 Use of the Console 129 9 1 Execution of a JGrass Command from the Console 129 A II A A 131 9 3 Execution of GRASS Commands from the Console 131 9 4 Index of GRASS Commands c sar ofa wh a a ES 132 10 Statistical Processing 143 10 1 Statistical Processing of Point Maps 0000 ee eee eens 143 10 2 Statistical Report ol the Data Sele sa dea ote A AS a wee ee 147 103 The Probability Den
135. nly one item is listed JGRASS test database By selecting this item and clicking the Finish button the workspace is loaded e008 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help Bo BH Bk QQQQQagaae 11101828 iom TEastingisosg99 Northing a9a5148 Elevatiomio JGRASS Test Database lt Ready Free working memory 467MB a Q Figure 4 3 Loading the JGrass Test Database workspace If the operation goes well the main menu will have some more dropdown menus and there will be another toolbar Furthermore one part of the screen will be white and the other will be green as can be seen in figure 4 3 The green area marks the limits of the computation area for the commands integrated in JGrass The commands that are launched only take into account the area delimited by the green frame in other words the white area of the screen The central white area is the so called active data 32 4 First Start Up of the Program region while the green area contains the default region in other words the maximum displayable region In the lower part of the JGrass screen some information which may be useful during processing is displayed as shown in figure 4 4 MAP SCALE WORKING RESOLUTION GEOGRAPHIC MOUSE COORDINATES trentino x Ready 0 Free working memory 236MB hitminewer a A STATUSBAR PROGRESSBAR MEMORY CONTROL LOADED
136. o have an idea of the correlation between available measures or rather of the spatial variability of the measure the concept of the semivariogram is used The semivariogram usually presents a tendency to grow with the distance reflecting a decrease in correlation with distance between pairs of points It represents the mean difference of the value of two points on interpolating surface at a distance h There are many types of semivariogram that can be adapted to the real one the main ones are listed in figure 10 11 If you use the g statistics command to interpolate a set of point data the first thing to do is create the semivariogram of the real data and find the model that best adapts to the specific case Once you have defined the semivariogram model to use you can proceed with the data interpolation Therefore check the do geostatistic interpolation option and select the point map to interpolate then click ok The window shown in figure 10 12 will appear the number of intervals and the maximum correlation distance in metres are required Click ok to continue with the calculations 150 10 Statistical Processing in Ri 4 j i The phenomena are spatial ly uncorrelated Stationary periodic processes with a period a Estimating this range all the scales present in the pheno mena are revealed 3 yh a 1 mi Li Non stationary phenomena Y 1 If O lt 0m lt 2 mean and variance are
137. of cells displayed in the graphic interface you will have to edit the command file etc prop r_correct_it properties and in the second line change the five for greater uneven number You can edit some values in the window and then click on another part of the map to open another window and so on Before exiting you can save all the changes in a single saving You can save the edited map with a new name or keep the original one Once all the parameters have been set and the editing operations are complete click the Accept Changes button to create the new map With this tool you can paste some data copied from a window of the same size created in a 83 5 First Steps with JGrass 06 r correct t ee Centered on coordinates 600011 75 4920310 5 Browse maps in PERMANEN 1406 0 1400 0 1400 0 1398 0 1398 0 aspect claysand dem 1406 0 1400 0 1400 0 1398 0 1398 0 lelevation dem esposizione_new geology 1411 0 1405 0 1405 0 1400 0 1400 0 1414 0 1410 0 1410 0 1407 0 1407 0 1414 0 1410 0 1410 0 1407 0 1407 0 map format grass Edited map PERMANENT Browse Accept Changes Cancel Figure 5 46 Graphic interface of the interactive raster editing tool in JGrass spreadsheet and so speed up the operation if you have to assign known values to an entire area 5 10 2 Editing Raster Maps with the Use of Polygons When you need to edit large areas of a map for example if you need to excl
138. oint you have to move the profile chart window so that the portion of map where you want a profile is visible and plot with the mouse the desired section The mouse pointer has a different appearance during this operation so that it is clear that you are now in plot mode It is sufficient to click on the first and last points of the desired cross section A blue line will appear on the map in correspondence of which a profile will be plotted see figure 5 23 In the profile chart window the information relative to the profile will be displayed more or less quickly according to the map resolution and the length of the cross section as shown in figure 5 24 The output of the r profile command are in the graphic part the profile of the map in corre spondence of the selected section with the maximum and minimum marked and the relative profile The other information in the profile chart window is numeric 1 coordinates of the first point of the section 2 coordinates of the last point of the section 3 section length 4 profile data progressive distance and altitude The profile data can be copied directly from the graphic interface and pasted into a spreadsheet To modify the information displayed graphically it is sufficient to uncheck the check boxes at the 67 5 First Steps with JGrass 0009 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help BO GBR QQqgqgqaaam oso ae
139. ology B activate value label M 111 0 M last 9 Figure 5 43 Graphic interface of the category editing tool in JGrass Here just as with the colormap tool you must select the map twice in order to load its range of values then load original categories If the map does not have a category table the category editing window does not change with this operation and you can proceed with the creation of new category table First of all you must fix the category intervals in the example we want to assign a description to each value of the map therefore you must create 9 interval boxes and insert what is listed in table 5 1 see figure 5 44 Once the categories have been inserted all you have to do is click the create categories button to create the table that has just been defined If the procedure goes well a message appears confirming the creation of the categories table in the cats directory of the current mapset You can now exit the tool by simply closing the dialog window and view the map and legend to check if the categories are recognised by JGrass as shown in figure 5 11 The r cats tool only works with discrete maps if you wish to assign categories to the aspect map which is a continuous map you would first have to create a new raster with a value for every representative interval of original data and only then assign categories As you might know the values of the aspect map represent the angle that the gradient forms with respect to
140. omplete and is available via the load workspace wizard Click the Finish button to exit the wizard lt Prev Next gt C Finish Cancel Figure 6 11 Closing window of the workspace wizard for the creation of a new workspace The new workspace is now listed in the load workspace window Figure 6 12 that appears by either clicking on the first icon of the toolbar or by selecting Load Workspace from the File menu 6 1 1 Loading an Existing Location To load a workspace that was created in GRASS or in a previous version of JGrass you need to follow the procedure described in the previous paragraph up to the point where you are asked 93 6 Creation of a New Workspace 006 Select workspace to load p JGRASS Test Database 3 Trentino Figure 6 12 Window to select the workspace to load in JGrass to select the pathname for the creation of a new workspace figure 6 4 but here select a path to an already existing location At this point you will skip directly to the dialog box where you can select the mapset to work with figure 6 8 Just as in the previous paragraph here you can load one or more mapsets or create a new ones and load them to the workspace Even here the new workspace will be listed with other available workspaces during the load workspace phase 6 2 Choice of the Reference System and Cartographic Projection The choice of the reference system and the cartographic
141. ossibility to use a Java based scripting language in order to automatize certain processes programmer and scientific work oriented e simplicity of use menu bars tool bars and icons aimed at simplifying the interface end user friendly Over the last number of years various attempts have been made to join the strengths of Java and GRASS the first of these was the wrapping of the GRASS libraries in Java by Alexandre Sorokine Shortly thereafter at the Centre for Environmental and Nuclear Sciences of the University of the West Indies Jamaica John Preston began the development of a Java Swing application for the visualization of geochemical maps At the beginning of 2003 Dr Rigon of the Department of Civil and Environmental Engineering and CUDAM of the University of Trento decided to start a new project on the shoulder of the the Jamaican and he supplyed funds and a developer and coordinated with the research group at ITC which includes Markus Neteler In this way began the development of JGrass He also disclosed the code of the Horton Machine a large set of Tools for terrain analysis which are one of the largest application of JGrass 2 0 At the moment JGrass is an application that can be run locally although the future implemen tation of remote running is planned It is a Java Swing application based on an MDI multiple document interface and provides standardized ways of interaction between the interface and the GRASS ker
142. ou will realise that by carrying out this operation the region limits are set automatically 80008 g region parameters Active Data Region M edit calculate active cells north 5114440 0 south 5110830 0 west 1637140 0 east 1640690 0 map format grass _ _ __ _ _ ____ 22 map selection dem Trentino Default Region edit set region from map extend region with map calculate active cells north 5114440 0 south 5110830 0 west 1637140 0 east 1640690 0 map format grass Y write the active region to disk default mapset _ write the default region to disk 4 Figure 6 15 Graphic interface of the region manager tool used to set the active data region to the dimensions of the imported map A view of the map with the new region settings is shown in figure 6 16 Take note that for a better view the zoom parameters were adjusted and the map was redrawn to the current display resolution by clicking on the redraw icon 3 in the map display toolbar 99 6 Creation of a New Workspace 80008 JGRASS Java GRASS Build 200604281059 File View Gis Raster Vector Extra HortonMachine Help vaso iom T a O Figure 6 16 Visualization of the map imported with the r in asci command In this way it is possible to import all the GRASS and ESRI ASCII raster maps you need for future processing The r in lidar Command By means of the r zn lidar command you can import
143. ow gt flowmapset lt flowmapset gt flowformat lt flowformat gt slope lt slope gt slopemapset lt slopemapset gt slopeformat lt slopeformat gt usegui The command is one of the geomorphological analysis tools integrated in JGrass It requires as input the depitted digital terrain model pit the drainage directions map flow as output it gives the slope map slope The options in square brackets are not indispensable for the execution of the command and can be omitted those that are not in square brackets must be specified Some options are particular and are present for all the commands e quiet allows you to follow the command progress actually this option is not very significant in JGrass e verbose shows you all the progress of the command and the internal console messages this option can also be activated with the console information icon e usage displays the option string shown above e usegut launches the graphic interface directly from the console it is the equivalent of clicking directly on the command icon 130 9 Use of the Console Therefore to execute the h slope command from the console you have to type h slope pit pit pitmapset trentino flow flow flowmapset trentino slope slope slopemapset trentino and to view the newly created map the command is d rast slope 9 2 Scripting The scripting language used by JGrass is the Java Beanshell language
144. portant to select the destination mapset even if it is the only one listed otherwise the map will not be copied and the procedure will have to be repeated from the beginning If the process went well and the map was copied successfully the message shown in figure 5 29 confirming the creation of the new map appears Click ok to end the operation 0200 Choose New Map Wizard Ol Location spearfish PERMANENT dem PERMANENT lt Prev Finish Cancel Figure 5 28 Last panel of the JGrass copy raster map wizard FP BDO Message 2 a elevation dem copied successfully to dem Figure 5 29 Closing message of the JGrass copy raster map wizard The new map can be viewed with the display command or used for the processing and creation of new maps Remember that the dem map is in the esriascigrid directory and is therefore saved in ESRI ASCII format and can be used as an exchange map with other applications To consolidate the concept of copying a map from one directory to another we propose that you also copy the other maps of the Spearfish dataset respectively e aspect to grassascii format with the name esposizione e geology to standard GRASS format with the name geologia 1 5 First Steps with JGrass 5 6 2 Renaming a Map The r rename mj command is used to rename a map or to move it to another directory or mapset The rename raster map wizard is very similar to the one for copying maps The first two pan
145. r very precise representations of a land area and the preparation of digital elevation models with resolutions as fine as lm x 1m There is therefore a substantial amount of data that must be visualized and processed in order to carry out the required environmental analysis JGrass will be enhanced with an innovative system for data visualization ROAM similar to that used at Livermore Laboratories of Berkeley as well as an efficient data mapping system for the number crunching routines 1 3 Extra Information We have been working on the JGrass Project for a number of years and a complete series of tools has been activated for both users and programmers These tools are e mailing list for users and programmers addresses and registration instructions can be found at http www hydrologis com jgrassml html in the Tools section e bug tracker to report bugs in the software to send a message all you have to do is go to https sourceforge net tracker group_id 144497 5atid 758942 and follow the instructions e manual The Horton Machine available at http www ing unitn it dica eng Quaderni index php 1 Introduction 2 An Introduction to GIS In this manual not much space will be given to the description of Geographic Information Systems and their development over the last number of years It is assumed that the user that approaches JGrass has a smattering of GIS For this reason only the main terms that will be us
146. rd Select GRASS location projection The projection is a mathematical means of displaying the 3 dimensional geographic information on a two dimensional computer screen Different projections are used for different types of maps for example a projection that accurately represents the shapes of the continents will distort their relative sizes Select the projection to use or Custom to define your own then Monte Mario Rome Italy zone 2 Monte Mario Italy zone 1 Monte Mario Italy zone 2 Filter EPSG Codes ita Figure 6 6 Window to select the reference system and cartographic projection parameters for the new workspace The next window has a summary of the the reference system and cartographic projection pa 90 6 Creation of a New Workspace rameters selected All the values are already set to default values the only ones that we advise you to edit in order to better manage the workspace are those referring to the region limits and spatial resolution For example the parameters of figure 6 7 are characteristic of the Trentino region in Italy To continue just click Next 0060 Workspace Wizard Select GRASS geographic window The GRASS workspace defines the geographic window also known as extent projection mapsets and default raster resolution Edit the window parameters listed below some of which have already been set then click the Next butto
147. re 10 5 the display colour of the points was changed by right clicking on the map name in the legend window and selecting proprieties from the popup menu JGrass 2 0 Trento File View Gis Raster Vector Extra HortonMachine Help Easting 1639982 trentino x Northing 5 113261 Figure 10 5 Visualization of a point map in GRASS format in JGrass Once you have the point map you can carry out the g statistics command with its various options 146 10 Statistical Processing 10 2 Statistical Report of the Data Set You can view a statistical report as well as a selection of data from the file specifying the number of rows to be displayed in the graphic interface by checking the first two options of the command interface figure 10 6 rparameters options info about the dataset Statistical summary about the dataset plot the probability density _ plot the ecdf and the pnorm _ do geostatistic interpolation map format grass the point ma as p siti_flanginec workshop number of rows to use columns to take into account number of steps for pnorm ok cancel Figure 10 6 Graphic interface of the JGrass g statistics command requiring a statistical report The so called statistical report gives the more important data of the data set contained in the map figure 10 7 number of data e
148. re 5 7 JGrass display options for loaded raster maps 000 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help BSS B El Map Grid Map Grid El North Arrow i North Arrow Map Scale F Map Scale Map Values Grid Legend Printarea Data Mask Ba amp E JGRASS Test Database x GRASS Test Database ew s AR ee Figure 5 8 JGrass map display properties e Map scale displayed the position parameters have been set so as to place it in the lower left part of the screen 56 5 First Steps with JGrass e Map values grid this has not been displayed because the option is not completely activated yet We advise you to display the map values grid only for small portions of the map at any one time as the operation could require some time Map Legend In order to display the map legend it is not sufficient to check the option that appears in the menu shown in figure 4 24 this option in fact only works after all the parameters necessary for the creation of the map legend have been defined In order to define these parameters you will need to select Legend from the properties list and define its properties If for example you wish to create the map legend for the elevation dem map you will have to do so by means of the interface shown in figure 5 9 i ene Map Legend Display Object Properties map for the legend elevation dem Tr
149. re 6 19 Output of the JGrass r in gdal command If you now try to display the imported map a message will appear warning you that the map is completely external to the displayed region You must redefine the region parameters or extend the region to include the new map figure 6 20 or you can set the region limits to the newly imported map figure 6 21 In this second case it will also be necessary to edit the default region and set it to the same map or extend it otherwise you would have the inconsistency of an active data region outside the default region 103 6 Creation of a New Workspace Ai S ooo E a G Figure 6 20 Extension of the active data region to include the new map imported with the r in gdal command emas O o O a Y Figure 6 21 Setting the active data region to that of the new map imported with the r in gdal command In the case shown if you zoom in the details of the provincial technical map of Trentino can be seen very well figure 6 22 The resolution of the new workspace if the region is set to the new imported map passes from 10 metres to 1 metre The map scale and the working resolution are displayed in the lower part of the screen If you use such extreme zooms by using a window zoom on a part of the map it is better to redraw the map at the current zoom in order to view it adequately 104 6 Creation of a New Workspace 0009 JGRASS Java GRASS Build 20060
150. reduce the snap value It is not possible to select various maps with the query vector map command you can query only one map at a time To exit the command click the exit button As a revision of a part of what has been seen in the previous paragraphs you can view the elevation dem map as in figure 5 21 and modify the map scale and the transparency options of the displayed maps 65 5 First Steps with JGrass AAO JGRASS Java GRASS Build 200604281059 File View Gis Raster Vector Extra HortonMachine Help i BoA GA RBrQagqggqgagaaw 55 BO 3 Raster Layers E Vector Layer 4 WM roads streams L SEA e06 d what vect 20 pactual maps Coord 594596 3125 4925361 0 roads streams Attributes the_geom ID MULTILINESTRING 792 E a rprevious Coord 608553 0625 4924831 0 Attributes o Easting 590462 Northing 4923594 Distance 13966 809605722417 Free working memory 196MB Figure 5 20 Graphic interface for the query vector map command 000 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help en Map Scale Display Object Properties 380 BAB BeRQQAQAA Transparency Factor Map Grid North Arrow Map Scale M Map Scale Y Position of screen X Position
151. rtvalue startcolor endvalue endcolor 4 p 4 Y a G G G G G EME a T M 1 1066 SELECT SELECT TTM aaa Recent aaa Ja M last SELECT 1840 SELECT PREVIEWLABEL UNDER CONSTRUCTION _ _ A EEEE es add rule load original colormap create colormap Figure 5 35 Graphic interface for the creation or editing of a raster map colormap in JGrass 800808 choose mapset PERMANENT choose map elevation d B HSB RGB activate startvalue startcolor endvalue endcolor M 1 1066 SELECT SELECT aaa alas Ja aaa Malal 43 m 2 SELECT SELECT M 3 SELECT SELECT mese 00 00 00 0 __ AL AAA DAA M last SELECT 1840 SELECT PREVIEWLABEL UNDER CONSTRUCTION load original colormap create colormap Figure 5 36 Graphic interface for the creation of a raster map colormap in JGrass creation of the data subranges you have to select it from the colours window on the right and then click the SELECT button in correspondence of where you want to assign that colour The active colour is also displayed in the Recent panel on the far right of the window Once the colours have been assigned you have to click the create colormap button This is followed by a message confirming the creation of the colormap and indicating the path to where this new file has been saved To exit the command you simply close the window An example of colormap definition is
152. ry will be created on the filesystem you only have to ok the message to continue 89 6 Creation of a New Workspace Workspace Wizard 8000 Create a GRASS location To create a GRASS workspace you must first identify a directory where the location database mapsets geographic boundaries projection information etc is stored Enter the path to an existing GRASS location or a new one to be created then click the Next button Workspace Wizard Y The selected location does not exist Do you want to create it Path Users erica grassdata gb_ovest 3 Description Gauss Boaga su Roma40 Fuso ovest Figure 6 5 Warning message that a new directory will be created in the filesystem In order to load a new workspace you need to specify the work region settings starting with the reference system and the the cartographic projection If you are unsure of the exact wording to use it is sufficient to write the initials of the country to which the data refers and a selection of the projections to use will be made automatically All you have to do then is select the correct option from the options proposed with the aid of the notes that appear by passing over the name of a projection with the mouse pointer as shown in figure 6 6 In the example it is proposed to lt Prev Next gt Finish create a location using the Gauss Boaga zone West projection e06e Workspace Wiza
153. s E a E A es add A of ond aspect Figure 5 45 Command to create a new raster map based on the aspect map but with data from table 5 2 32 5 First Steps with JGrass CATEGORY NUMBER INTERVAL EAST NORTH EAST 0 22 5 22 5 67 5 NORTH 67 5 112 5 NORTH WEST 112 5 157 5 WEST 157 5 202 5 SOUTH WEST 6 202 5 247 5 SOUTH 247 5 292 5 SOUTH EAST 8 292 5 337 5 EAST 9 337 5 360 Table 5 2 table with the aspect angle values for the creation of the map categories 5 10 Editing Raster Map Values Sometimes it is necessary to edit in some way or another raster maps for the most diverse of reasons If you should need to do so the tool to use is r correct Actually there are two versions of this tool e r correct allows you to edit all the cells of a raster map one by one e r correct polygon A allows you draw an area on the map and assign a specific value to the entire area 5 10 1 Editing Raster Maps Manually The tool to manually edit a raster r correct allows you to view the data of a map selected from a list of available maps in a mapset and to edit them manually The tool shown in figure 5 46 refers to a portion of the elevation dem map Using the standard tool options it is only possible to view an area of five cells by five cells horizontally and vertically around the cell selected with the mouse To change the number
154. s of the user specified data type to standard output g manual display the HTML man pages of GRASS g mapset Change current mapset g mapsets Modifies the user s current mapset search path affecting the user s access to data existing under the other GRASS mapsets in the current location g mlist Apply regular expressions and wildcards to g list g mremove Apply regular expressions and wildcards to g remove g parser g parser g proj Prints and manipulates GRASS projection information files g region Program to manage the boundary definitions for the geographic region g remove Removes data base element files from the user s current mapset g rename To rename data base element files in the user s current mapset g setproj g setproj g tempfile Creates a temporary file and prints the file name g version Displays version and copyright information 132 9 Use of the Console 1 X commands Command 1 cca i class i cluster Command i fft i fusion brovey 1 gensig 1 gensigset 1 group i his rgb 1 ifft l image mosaic 1 maxlik 1 O1f i ortho photo 1 pca 1 points 1 rectify 1 rgb his 1 smap i spectral i target i tasscap 1 vpoints 1 ZC Description Canonical components analysis cca program for image process ing 1 Class An imagery function that generates spectral signatures for land cover types in an image using a clustering algorithm The re sulting signature file is us
155. s the other directories accessible from JGrass Click Next to continue Once you have chosen the directory of origin it is possible to choose the map to copy from the list of loaded mapsets In the example of figure 5 26 the elevation dem map is being copied Once you click finish a panel similar to the previous one appears where you are asked to choose the destination directory In the example the map is copied to the esriasciigrid directory see figure 5 27 Click Next to continue 69 5 First Steps with JGrass 606 Copy Raster Map Wizard fluidturtleascii a grassascil grassbyrow esriasciigrid lt Prev Next gt Cancel Figure 5 25 First panel of the JGrass copy raster map wizard F 4 006 Copy Raster Map Wizard El Al Location spearfish E PERMANENT lt Prev Finish Cancel F fA Figure 5 26 Second panel of the JGrass copy raster map wizard 6068 Choose New Map Wizard fluidturtleascii 7 grass H grassascii grassbyrow esriasciigrid lt Prey Next gt Cancel Figure 5 27 Third panel of the JGrass copy raster map wizard 70 5 First Steps with JGrass In the last panel you are asked to choose the mapset where you want to copy the map and to write the name with which to save it In the example the only loaded mapset is PERMANENT therefore once you have selected the mapset and written the new name dem you can click Finish to end the operation It is very im
156. sity Functio s t s s e ea A A BD ce ee we 148 10 4 The Cumulative Distribution Function e 149 10 5 Geostatistical Interpolation with the Kriging Interpolator 150 11 Printing 157 12 Uninstalling 161 111 CONTENTS 1V 1 Introduction We have been asked to write a JGrass manual for quite some time and now we have finally decided to do so The manual that we now present to you tries to follow the logical steps applied when using JGrass starting with a presentation of the programme and the main algorithms that are imple mented then passing to the definition of particular environmental parameters in particular hydro logical and geomorphological ones This manual will give you a general overview of the capacities of JGrass it will also give you some hints and ideas on how to solve certain spatial problems In the HTML version of this manual http geoserver ing unitn it jgrass there are two ways to proceed the pages are ordered in a linear fashion At the beginning and at the end of each page there are four directions to choose from The left arrow takes you back to the previous page which not necessarily is the last page viewed while the right arrow brings you to the next page of the manual Clicking on the link to the index brings you to the contents page of the manual with a brief description of each chapter Finally the A Z link brings you to an analogical index of all the JGrass modules
157. spearfish as moovida a y gt ee Y Objects SOL Sl spearfish Row IDs Versions H information_schema y 1 oa 1 EF ars C3 pg_catalog Info Content Row Count Columns Primary Key Exported Keys Imported Keys Indexes Privileges Column Privileges public H E INDEX al il il Signature Rock lt Other gt 114854241 H O SEQUENCE 2 2 2 No Name lt Other gt 114854242 SYSTEM INDEX 3 3 3 Canyon Station lt Other gt 114854243 H O SYSTEM TABLE 4 4 4 Spearfish Creek lt Other gt 114854244 a SYSTEM TOAST INDE 5 5 5 No Name lt Other gt 114854245 a SYSTEM TOAST TABL 6 6 6 Prairie Site lt Other gt 114854246 SYSTEM VIEW 7 7 7 Jensen Pass lt Other gt 114854247 E TABLE Z 8 z No Name lt Other gt 114854248 D 9 9 9 No Name lt Other gt 114854249 bugsites 10 10 10 Slaughterhouse Gulch lt Other gt 114854250 L geometry_columr 11 11 11 No Name lt Other gt 114854251 3 L roads 12 12 12 Elkhorn Peak lt Other gt 114854252 L spatial_ref_sys 13 13 13 No Name lt Other gt 114854253 streams 14 14 14 No Name lt Other gt 114854254 TEMPORARY INDEX 15 15 15 No Name lt Other gt 114854255 EH TEMPORARY TABLE 16 16 16 Boulder Creek Cabin lt Other gt 114854256 Ca VIEW 17 17 17 Ridge lt Other gt 114854257 H 8 PROCEDURE 18 18 18 Cole Creek Mine lt Other gt 114854258 a UDT 19 19 19 No Name lt Other gt 114854259 20 20 20 No Name lt Other gt 114854260 mr ler Hi pr EG Wihiteswood Clate Othors AIAQOCAIG
158. ss analyse store and display in graphic and alphanumeric format data referred to a certain land area GPS Global Positioning System A system that by means of a receiver software and a constellation of satellites allows you to determine the position and altimetry of a point with a precision that goes from a few millimetres to a few metres depending on the type of equipment and the operative procedures of detection used Image processing Set of activities relative to the processing of images in raster format Many of the techniques used in this discipline require complex mathematical procedures and are aimed at determining the phenomena described by the image such as pollution humidity and temperature at the surface vegetation type etc L Layer see informative layer Legend An instrument present on the map which associates the graphic symbols used to indi vidual characteristics and so consents a precise reading of the map Longitude see geographic projection M Map A map is a graphic representation of geographic elements and other spatial phenomena lakes rivers roads cities that gives two types of information about the area that is repre sented position and appearance The position informs where a certain geographical element is 10 2 An Introduction to GIS found on the surface of the Earth and what is its relation with other elements The appearance illustra
159. ss_boaga_ovest postgis xml OK Figure 8 16 Error message for connection to the Postgis spatial database If the postgis xml file has been created correctly and saved in the JGrass location directory you can proceed to view the data The window for viewing Postgis data is very different from the standard JGrass window It allows you to choose the database to connect to and the tables to view figure 8 17 126 8 Environmental Databases Database Chose databases tables u Figure 8 17 First window to view data from a spatial database with Postgis By scrolling down the dropdown menus of the two fields one listing the available databases for the workspace and the other listing the tables therein you can choose the map to view figure 8 18 ix Database Chooser databases osnabrueck X tables gewassaerflaechen gruenflachen poi strassen Figure 8 18 Window where to select the map to be viewed from the list of spatial database data In this case you can view polygons lines and points as shown in figure 8 19 127 8 Environmental Databases kKkKkKkKkKkKkKkKk k k kk A S File View Gis Raster Vector Extra HortonMachine Help 1B RQQQ QQAAAAD BS5i Be 3 Raster Layers E Wector Layer K gewassaerflaechen k poi K gruenflachen Point Layers osnabrueck x Figure 8 19 Visualization of
160. staller from our web site you will have an archive file with a jar extension its default name is jgrass_installer jar www hydrologis com 3 Installation Windows On some versions of Windows if you download a jar file this is automatically renamed with a zip extension If this happens it will not be possible to carry out the installation first the file must be renamed again with its correct jar extension and you will then be able to proceed with the installation This is only a little of the enterprising spirit typical of Windows The file is an executable java archive and a double click should launch the installation However in some versions of Windows the connection to Java for the the execution is not recognised In these cases it is necessary to launch the installation from the command line by typing java jar jgrass_installer jar In many cases however it is sufficient to set the file as a Java executable application and then double click on the file icon the installation will be launched Linux In the Linux environment almost no browser supports the execution of jar files Therefore unless you are one of the lucky few open a console change the directory to the one containing the installation file and type java jar jgrass_installer jar MacOSX The MacOSX environment supports the execution of jar files it is sufficient to launch the installation by double clicking on the file icon
161. statistical operations which will be presented in following paragraphs 123 8 Environmental Databases 8 2 2 The Interface for a Spatial Database A spatial database as mentioned previously contains all the information about geometry and about the reference system and cartographic projection Potentially it can contain all the features that a GIS can support points lines polylines and polygons Even here for a JGrass connection to a database of this type you need to write a connection configuration file Paradoxically this file or rather this type of connection is much simpler than that used for point data because the spatial database tables have all the information needed for viewing the data You have only to add a data source called Postgis Postgis refers to visualization of data on a PostgreSQL type database with a Postgis spatial extension Before considering the JGrass aspect the data from the Spearfish spatial database is displayed As can be seen in figure 8 14 in this case other than the data tables roads archsites bugsites and streams there are other tables with spatial information e geometry_column geometric descriptions in binary format of all the geometric shapes con tained on the database All the data in the the_geom field of the data table refer to this table e spatial_ref_sys reference system and cartographic projection information 3 2 spearfish
162. stem Another uninstall option is simply to remove the directory where JGrass was installed In fact JGrass is completely installed in its installation directory and does not need files in other filesystem directories The more expert users can also uninstall the program from the console command line by exe cuting the uninstall jar file found in the Uninstaller directory of the JGrass installation directory 12 Uninstalling 162
163. stics software already installed on your computer In the dialog box relative to the installation options shown in figure 3 5 you need to input the complete pathname of the directory containing the R executable file and the connection application for JGrass called Rserve exe in the space corresponding to R The text to be inserted is C Documents and Settings Utente R bin Rserve exe owww grass itc it www r project org 2i 3 Installation The Rserve exe application can be installed in the following dialog box by selecting the item R engine and later copying it to the directory containing the R executable file e MacOSX and Linux both programs must already be installed GRASS insert the complete installation path for the GRASS commands in the dialog box of figure 3 4 in the space corresponding to GRASS R insert the path to the R executable file in the dialog box of figure 3 4 at the line corresponding to R With these operating systems the Rserver package is installed like any other R package by downloading it from the web For this reason only the path to the R executable is needed and not the path to the Rserve package 3 3 1 The R Packages Used The programs developed in JGrass that rely upon the R connections use specific commands from some R packages Unfortunately not all of these packages are included in the basic version of R and therefore they must be installed separately following the speci
164. t for what lies outside the region By deactivating this option the entire window is white even though only a part of it is the active data region e Legend allows you to eliminate the legend from the display and to view it only when all the necessary options have been configured e Automatic Redraw activates the automatic redraw function so that all maps are redrawn every time an operation that changes the display is carried out for example a change of zoom or a new map being loaded The configuration of the the elements selected can not be modified from this menu for this operation please refer to Paragraph 5 3 1 Display Options 48 5 First Steps with JGrass 5 1 The Spearfish Test Data Set The free Spearfish data package which is installed automatically with JGrass contains raster vector and point data The name derives from the name of the area in South Dakota USA to which the data refer The data are given in a UTM conic projection with Clarke66 ellipsoid and NAD27 datum These projection data which may seem strange to an Italian user are of common usage in the USA Furthermore the type of projection used is not a fundamental factor while working within a single workspace as long as it is coherent with the data being used it does become fundamentally important when working with maps from different workspaces 5 2 Region Parameters If you want to view the boundaries of the active data regio
165. t this will be given in Paragraph 3 3 External Programs Set the preferences Location of the java runtime environment Path to the runtime environment Hhomefsilli jak1 5 0_04f UserlnputPanel search browse Set application language en it de es fr Set the initial Java heap size in Mbytes Set the maximum Java heap size in Mbytes Environmental variables for particular needs Leave as is if unsure Full Path to the R executable Path to the GRASS GISBASE for Windows leave as is Creato con IzPack http www izforge com Q Indietro O avani Q Esci Figure 3 4 The screen panel with the installation options In the following panel the chosen parameters are summarized so allowing you one last check before the actual installation At this point it is still possible to turn back and modify the setup In the following step you must select the packages to install Figure 3 5 binary the base package for the installation of JGrass windowsbinaries package of precompiled GRASS commands for Windows src the JGrass source code testdataset a data set to be used for an initial launch of JGrass 19 3 Installation i 606 IzPack Installation of JGrass f Select the packs you want to install Q Note greyed out packs are required vV binary 30 52 MB windowsbinaries 139 76 MB FA sre 8 11 MB Y testdataset 3 48 MB Description Compiled GRASS commands only for Windows XP
166. ta file Trentino C browse grid type Browse region settings Si mean 3 min max what to do with duplicated points ok cancel Figure 6 17 The r in lidar graphic interface in JGrass The r in gdal Command This command is one of the native GRASS commands It allows you to import all the formats that are supported by the GDAL libraries The graphic interface is very simple it allows you to select the input file in any directory by means of the browse button and to define the operations that can be carried out 16 6 3 select the colour band to import when importing image files if no colour is specified all the colour bands are imported and a raster is created for each band a suffix relative to the colour is added to the name e g red be congruent with those of the current workspace outside the active data region www gdal org list the supported formats 101 define the location name where the data projection is to be read extend the region limits to those of the imported map define the name of the new location to be created if the projection characteristics should not ignore the information about the region limits so as to be able to import even maps that are 6 Creation of a New Workspace 7 consider the band number rather than the name of the colour when importing images In the example given the optio
167. tained in the database corresponding to the configurations saved in the sql file directly from JGrass To do this you must view the data as points sites that is to say click the icon in the map display toolbar The display wizard integrated into the command provides a first window were you can select the format of the data to be viewed in this case Figura 8 12 the data to be viewed is in sqldatabase format 122 8 Environmental Databases AA 1 E rie F yy 42 Please select the format of the site data Site Data Format grass M saldatabase Next gt Cancel Figure 8 12 The first window of the display wizard to view point data from a PostgreSQL database By clicking Next you can select the maps to display Each one of these maps is the result of a specific query to the database which is saved in the corresponding sql file This is why in the graphic interface the names of the point maps do not appear but rather the names of the files in the sql directory figure 8 13 E a Location gauss_boaga_ovest SA trentino lt Prew Cancel Figure 8 13 Second window of the display wizard to view point data from a PostgreSQL database Once you have selected the desired map click Next and then Finish to display the points At this point all the processes that can be carried out with JGrass sites can also be carried out on the points extracted from a database Of particular interest are the geo
168. tes both qualitative and quantitative characteristics of the element represented Other than the spatial and descriptive information every map also has some technical characteristics that de fine it and determine its use These characteristics include scale accuracy projection system and coordinate system Mosaicing A series of operations in a GIS environment by which different digital maps are joined together so as to have territorial continuity N Nominal scale A parameter that defines the reference scale of a digital map as a function of the corresponding scale of a traditional map made with to the same metric precision requirements O Overlay topological Spatial analysis operation where the informative layers are superimposed and intersected In this way the information from each layer is joined in a new synthetic layer P Photointerpretation Technique which allows experts to determine and classify territorial phe nomena by reading aerial photographs or other remotely sensed images Examples include vegeta tion typology faultline identification and the updating of existing cartography R Raster image Any image can be thought of as being made up of a set of small equal areas called pixels arranged in rows and columns so as to form a matrix The values associated with each cell can express either graphical information colour greyscale etc or descriptive information temperature slope
169. th path to the GRASS libraries binpath path to the GRASS command binaries esrigridpath directory where files in ESRI ASCII Grid format are to be saved for their direct management with JGrass fluidturtleasciipath directory where files in FluidTurtle format a swap format between JGrass and GEOtop a catchment area hydrological balance application used mainly for small mountain catchments are to be saved for their direct management with JGrass grassasciipath directory where files in GRASS ASCII format are to be saved for their direct management with JGrass shapepath directory where files in shapefile format are to stored in order to be viewed in JGrass by means of the d vect command This option has been outdated with the introduction of the new d shapefile command which allows you to view this type of file saved in any directory of the filesystem sqldbpath directory where the files containing the query definitions for the database are saved Even this option is partially outdated by the direct connection to the PostGIS database jgrassgrouppath directory used for the management of groups of raster maps created in JGrass Under development commands name of the file with the definitions of the executable JGrass commands epsgdata path to file with the cartographic projection definitions given by the OGP Sur veying and Positioning Committee 2 WWW epsg org 45 4 First Start Up of the Program Frame
170. the reference systems and projections used in different countries For coded digital maps in certain file formats it is possible by means of a series of commands which shall be illustrated later to create on the basis of the file itself a new location that is coherent with the map in terms of reference system and projection This operation is only possible with those file formats that contain other than the map the meta information that specifies the reference system and the projection For those file formats that do not include this information e g the ASCII formats it is necessary to manually create a location which is coherent with the map that you want to import In this case you can refer to EPSG codes that allow you to create a location without having to manually insert all the parameters that define the reference system and the cartographic projection of the map Specifically in JGrass in the window where you are asked to select the reference system and the projection figure 6 6 it is possible to select the opportune EPSG code and so load the EPGS specified parameters automatically With reference to Italy among the available options for the choice of reference system and projection the phrase Gauss Boaga on Rome 1940 does not appear This combination is indi cated internationally with two titles depending on the longitude associated to the Italian reference meridian the one that passes through Rome Monte Mario
171. the settings of workspaces which will be created Having said all this it is advisable that you keep the JGrass directory only as the application container while you keep all data you are working with the so called workspaces in a separate directory on your hard disk which you can call workspace or jgrassdata jgrassdb or simply data 23 3 Installation In this way a new version of JGrass can be simply installed over the previous version and the data and configurations of the previous version remain unvaried Only the example data are installed in the main JGrass directory because they are installed anew with each new installation and therefore they can be overwritten without any problems 3 5 Data Structure The structure with which data are written in order to be processed with JGrass is based on the GRASS structure and it has been studied in such a way that you do not have to deal with it directly very often By all means it is important to know the data structure because it helps during the data import and export procedures The data that are used in JGrass must be saved in a directory called DATABASE that the user makes on his filesystem independently of JGrass In the DATABASE directory data can be organized according to project or area and saved in subdirectories called locations A location is defined by its coordinate system cartographic projection and the geographic limits within which the work region is fou
172. to activate the automatic redraw mode as 54 5 First Steps with JGrass explained in Paragraph 4 4 so that these operations are carried out automatically by the program This choice is convenient if you are dealing with few data 1t slows everything down if you have to manage a lot of data or if you have a lot of maps loaded Display Options To control the map display options it is necessary to display the Legend window by clicking on the button In this window you can decide whether to display a loaded map or not by simply checking the check box in correspondence of the map name You can also remove loaded maps from memory to speed up the visualization process when they are no longer needed To remove a loaded map it is sufficient to right click on the name of the map and choose the option Remove map name This operation removes data from RAM it does not remove data from the filesystem In this way you can avoid overloading the memory of your computer which would slow down the display operations and calculations The maps that are removed can be displayed again at a later stage should the need arise by loading them from the hard disk By right clicking on the name of the map you can also define the transparency to assign to it Figure 5 7 shows an example where the geology map has been loaded but is not displayed The same figure shows the popup menu that appears by right clicking on the aspect map and the window that
173. tributes Table Tables are an integral part of the informative layer Each table refers to a homogeneous group of geographic elements of the map roads rivers contour lines etc and is made up of a variable number of rows and columns Each row record contains the description of a single geographic element Each column field or attribute stores a specific type of information The characteristics of the geographic elements are usually expressed in alphanumeric code before being input to the table B Base cartography It is the set of maps of a certain area made with topographical or pho togrammetric means that show the planimetry watercourses roads railways bridges buildings etc and altimetry by means of benchmarks or contour lines of the area C 2 An Introduction to GIS Coordinate System see Reference System D Database A database is a set of different types of information These data are organized accord ing to precise criteria that allow quick consultation Digital cartography In the digital version of a traditional map the position and the description of an element are memorized in a series of files on the computer To identify the position of an element an x y or x y z cartesian coordinate system is used each point is represented by a single pair of x y coordinates each line is stored as an ordered series of x y coordinates each area is stored as an ordered series of x y coor
174. u the point map format to be displayed As a general rule select the GRASS format insomuch that or click on the icon The window shown in figure 10 2 will appear where it is possible to select the other formats are in substitution phase with the relevant commands Click Next to continue 144 10 Statistical Processing Please select the format of the site data Site Data Format grass sqidatabase shape grass Next gt Cancel Figure 10 2 First window of the site point map wizard in JGrass The second window figure 10 3 allows you to select the mapset where the data to be displayed is found in the example the trentino mapset has been selected it is the current mapset where the file with point data has been saved Click Nezt to continue E a Location gauss_boaga_ovest E E trentino siti_flanginec Cancel Figure 10 3 Second window of the site point map wizard in JGrass The next window allows you select the point display options the character used the colour and the dimensions of the point Select the desired configurations and click Finish 145 10 Statistical Processing Choose Site Point Map Wizard Please select the symbol Size Multiplier 1 Line Width 2 Symbol Color red C Preview symbol lt Prev Finish Cancel Figure 10 4 Third window of the site point map wizard in JGrass The resulting point map superimposed on the DEM is shown in figu
175. ude areas of a catchment area that drain artificially into other catchments the r correct polygon tool is very useful With this tool you plot a polygon on the map to be edited and so delimit an area to which to assign a specific value even the null value in fact in the example of figure 5 47 the null is assigned to the area contained within the polygon The plotted polygon is visible in blue in figure 5 48 r _ e608 r correct polygon parameters map format grass elevation dem OPERMANENT Browse null gt Value to use for correction F TASS ok cancel Raster map to correct Figure 5 47 Graphic interface for raster map editing with the use of polygons in JGrass To create a new map it is necessary to click ok after having plotted the polygon to start the processing The exact map display shown in figure 5 49 was obtained by removing the plotted polygon from the menu options in the legend panel of the main screen 34 5 First Steps with JGrass 0009 JGRASS Java GRASS Build 200605080954 File View Gis Raster Vector Extra HortonMachine Help FQARAAAALAE B55 BR 3 Raster Layers ea Vector Layer Point Layers Easting 609300 Northing 4925422 Elevation 0 JGRASS Test Database O LS A YO A Figure 5 48 The delimiting polygon to which the null value will be assigned 80008 JGRASS Java GRASS Build 2006050809
176. w thematic map e g the superimposition of a natural park boundary over a map of the administrative regions so as to determine the jurisdiction of each municipality or the the percentage of protected area in each municipality e Spatial querying that is the interrogation of data according to spatial criteria vicinity in clusion superimposition etc e Buffering defines a polygon around a point line or polygon at a fixed or variable distance 2 An Introduction to GIS as a function of the attributes of the element e Segmentation algorithms usually applied to linear elements in order to determine a point at a specific distance from the beginning of the element e Network analysis algorithm to determine the shortest route between two points of a linear network e g road network 2 5 Glossary The definitions in this section make reference to the on line GIS term glossary the complete and updated version can be found at http www glossari it glossariogis html A Attribute Descriptive information associated to a geographic object which characterizes it Gen erally it is used to indicate the non graphic characteristics of an element or those graphic charac teristics which cannot be represented at the scale of acquisition For a linear element arc that represents a road the attributes could be the type of paving the average number of vehicles that transit the width etc At
177. work GRASS Environment Cluster Console Parameter Mame Parameter Yale Idishase usrflibfgrass scriptpath scripts ippath fs fli grass fli binpath sd fis fli fgrass fin jesrigridpath esrascigrid fluidturtleasciipatn ffluidturtleascii grassasciipathn grass shapepath i site_lists sqidbpath sgl jgrassgrouppath i jgrassgroup commands commands xml Jepsgdata usriflocal share projfepsg Figure 4 20 The GRASS configuration panel window under the Linux and MacOSX operating systems El Grass Preferences Framework GRASS Enironment Monitor Cluster Console Parameter Mame Parameter Yalue Igisbase scriptpath scripts libpath i binpath ti Jesrigridpath fesriasciigrid fuidturtleasciipath fuidturileascii grassasciipath grassascii shapepath site liste Isqldbpath sal igrassgrouppath ligrassgroup commands lt commandsxml epsadata _ lusiflocalisharelproiepso Figure 4 21 The GRASS configuration panel window under the Windows operating system Monitor In this section the display options are defined We again point out that many of these specifi cations are only modifiable by those users that are very familiar with both the operating system and the application program What you will find in this section is shown in figure 4 22 The most important thing to highlight in this section is the possibility to change the graphics

JGrass 2.0 User Manual - Università degli Studi di Trento

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JGrass 2.0 User Manual - Universit&agrave; degli Studi di Trento

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JGrass 2.0 User Manual - Università degli Studi di Trento