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1. Also it could be relevant to see if other data should work as selection data like the data describing ownership and type This could be show only data using standardized measurement methods or something similar It could also be relevant to look into how non spatial data could be represented in the web application As demonstrated in 4 Results the non spatial data can be accessed in two ways visually some data can be read from looking at the map and in the data box in the bottom of the screen Datais only communicated through GeoServer which makes non spatial data difficult to deliver If more time for imple mentation was available it would have been relevant to investigate how users could access data in other ways that only spatially Examples could be e To give the user access to the development of the measurements of a certain compound in a certain facility or area presented on charts orin a spreadsheet e To give the user access to specific data about more than one selected facility This could be by boxing circling or choosing one or more municipalities for selection 7 3 Improve the performance and interoperability A longer implementation period would have made performance improvements possible As discussed earlier the performance is an important issue Certain performance configurations can help improve the performance The data structure could be reviewed and literature about performance scrutinized to improve the performance
2. WMS architecture Besides the three major tasks of WMS there are four major processing stages in WMS filter service display element generator render service and display service Cuthbert 1997 mentioned about these four stages which describes data visualization from data to map that is showed in Figure 13 Stage 1 the selection of geospatial data to be displayed Stage 2 the generation of display elements from the selected geospatial data Stage 3 the rendering of display elements into a rendered map and Stage 4 the display of the rendered map to the user 33 Thin Client image constraint Medium Client Style Thick Client Query constraint Data Source Figure 13 Map display process and relationship with clients Source Peng and Tsou 2003 The whole map display process can be integrated with the client server relationships for example thin client thick client and medium client If only rendered map is carried over the Internet to the client it will be athin client system There is no client side capabilities present in the process GIF files are such kinds of rendered maps If the display elements are carried over the Internet to the web browser it would be a medium client system Medium client system allows very limited opportunity for client side processing like panning zooming and selection And if the geospatial data and display element generator service is carried over the internet to the web client it wou
3. Parametric view The parametric view or the SQL view is a feature in GeoServer allowing parameterized queries using string substitution to a spatial database GeoServer 2012 WMS or WFS can as previously described be used to represent data from spatial databases With the parametric view a dynamic view to the spatial 37 database can be created This allows for querying using SQL and in the SQL parameters can be inserted like this SELECT FROM spatial data WHERE column name value Here values is the parameter adding the dynamics to the query When the WMS or WFS is requested in JavaScript from the GeoServer parameters can be set to alter the view An example could be layer mergeNewParams viewparams value 100 Then only entries in spatial_ data where column_name 100 will be in the view which will reduce the number of features in the layer Even more dynamics can be added to the query if the left part of where equation is parameterized or other and bigger parts of the query An unlimited amount of parameters can be used in the queries but they must all have default values to use if no parameter is parsed with the mergeNewParams command Regular expressions For hackers wanting to gain access to the database that the view is pointing to or even others on the same server parameters should be protected using regular expressions also known as Regex Regex is a language for matching strings in GeoServer parametric vi
4. The first impression of the styling of the data is shown on Figure 44 Figure 44 Data showed when loading the style at first All the points of discharge are shown categorized in 3 colours green yellow and red signifying good medium and bad From this first picture it is easy to identify everything is not as it should be there are more red ones than green ones which is the basic message of this map The huge number of points makes it possible to see the contours of Denmark even without any boundaries or costal lines The size of the dots is designed to fit the map without too much overlap between each point It is sought to make it all as intuitive as possible to fulfil the needs of both the professionals and the citizens When zooming in the design keeps its style until the range of 1 500 000 At the range of 1 600 000 it looks like Figure 45 But at 1 300 000 it looks like Figure 46 R nde T strup Feldballe e o o e gt Egens e y A e e E Knebel a Bjodstrup Landborup A a e M r a arselisborg e Figure 45 points at a large zoom Figure 46 points at a close zoom We made the points bigger to underline the important elements in the map Furthermore we attached the name of each facility to the point of discharge to improve the identification of each point 72 We added the municipality borders as a selectable layer Users who want to add this layer to the maps w
5. A a eS Figure 51 Lead measurements Figure 52 Lead measurements and all treatment sites Figure 51 and Figure 52 are two screenshots showing data for lead measurements which has not been conducted on all facilities points of discharge The blue dots representing the Facility location is very much distracting the image and it makes the important data less readable Ideally the blue dots and pipes would only show corresponding to facilities where there is data available Selection code Code have been created that through the parametric view allows the user to have only measurements from a named facility shown or only measurements from facilities in a named municipality shown But the 81 JavaScript functionality has not yet been implemented So the code is not assigned to any buttons or input fields but is written andis commented out in the code because of time limitations Performance and drawing The Open Street Map background map uses the Spherical Mercator projection OSM wiki 2012 As this is the background map and it consists of tiled images the overlay layers will have to be in the same projection in order for them to be shown correctly No matter which projection the GeoServer WMS layers are served in can easily reproject them to the projection of the background map But this reprojection takes some time Therefore ideally the WMS layers should also be in Spherical Mercator projection to save time on the reprojection This h
6. Longley 2004 252 DBMS reduces data redundancy Therefore the maintenance cost of data is low as it decreases data duplication by storing data in one place Many users can use database management systems that help to improve the management the system and thus can transfer user knowledge to the system In DBMS data security is highly established The biggest advantage of DBMS is to maintain standards and security It helps 17 to make files more consistent to manage data in an easier way when multiple programmers are involved Data is easier to access and manipulate through it It also reduces the reliance of individual users on computer specialists to meet their data needs DBMS allow multiple users to access the same data resources Though users are benefitted this way there arise some security risks due to it It is necessary to protect some information Through the use of passwords database management systems can be used to restrict data access to only those who should see it Longley 2004 On the other hand DBMS has some disadvantages The initial cost of acquiring and maintaining DBMS software can be high and in some cases DBMS can be complex in data management The implementation of DBMS system can be expensive and time consuming For large organizations training requirement alone can be very costly Longley 2004 Types of DBMS There are four structural types of database management systems hierarchical network relational and obje
7. To better understand the project some information and theory is needed In our report we discuss system design strategies theory on database management systems web architecture programming languages and web based GIS This section will give understandings of different concepts used Phase 2is where data preparation and methods are discussed In the methodology section we describe our system design database structure design and user requirements for the project Then we discuss the implementation process where we discuss system implementation and user interface design This phase also includes the methods we follow in the implementation Next we present our results by using web applications and taking some screenshots of the outputs 11 The last phase of the report is discussion and evaluation phase which contains discussion and conclusion In the discussion part we discuss the choices and outputs from the choices It also includes the shortcomings of the work In the conclusion part we answer our three research questions and in the end we look at the project perspectives 12 2 Theory In this chapter an introduction to the theoretical aspects of the project will be presented We will have a lookinto different system design strategies Afterwards we will focus on describing the underlying pillars of the theoretical aspects in the project 2 1 System design strategies In the following section two system design strategies is discussed
8. o Controls Zoombar 54 Navigation getFeature Mouse position e Panel in the bottom Here information about a clicked facility is shown o Info about clicked features o Bottom bar GeocoderComboBox for facilities GeocoderComboBox for munidpalities e Panel on the right hand side Here everything is controlled o Simple tab Legend Compounds picker dropdown Zoom to Denmark Layers add Compound information o Advanced tab Custom limits Selection of facility types Selection of facility ownership History slider Update button Reset button It applies that every element that is a child of another must be defined before its parent within its parent or be added to the parent after both the child and the parent are defined For example the compounds picker dropdown is defined before the Simple tab because it is a child of the Simple tab GIS Analysis In this section we will describe how we have used GIS analysis to create spatial analysis To create some of the extra features we added to the application we used GIS as a tool to create these features We used common toolsin ArcMap to do the analysis GeocoderComboBox data preparation The GeocoderComboBox js has a build in configuration of the wanted zoom level But there is a bug in the script so it always zooms to the bounding box of the selected feature ignoring the zoom configuration That means if the selected feature is a point which by definition has
9. var ct4 formAdv getForm getVal Is var ct5 formAdv getForm getVal y 3 var ct99 formAdv getForm getValues checktype99 if ct2 0n 8 ct4 on amp amp ct5 0n s ct99 on alert No facility types selected elsel array for making string to parse to sql view for the facility types var a new Array if ct2 on a push 2 if ct4 on a push 4 if ct5 on a push 5 if ct99 on a push 99 types syntaxer a type First four local variables are defined they are set to either on or undefined whether the four checkboxes are checked on or not undefined The checkboxes are elements of the form called formAdv and they are individually called checktype2 checktype99 Then there is an if else statement checking whether any of the checkboxes are checked or not If none are checked an error message will appear If this is not the case the else code will be executed Here an Array a list called a is created locally The list will then have 1 4 elements appended with the JavaScript build in method push In the end a global variable will assigned to a string using the function syntaxer which was explained in the first part of this section Important syntax to notice is the semicolon in the end of each executed line If a line is broken up into several lines but only have one semicolon it will be r
10. y Other View Historical data Showing data from 1 July 2012 Update Reset Figure 40 The advanced tab options private municipal and other in three checkboxes The historical data is the next tool It is positioned under the Select ownership types and is represented by a slider bar Under the bar there is text where the chosen date is written Figure 41 42 soe advance Nae Currently selected compound is BIS unit mg l National limit 75 min km Select displayed plants by type Y leaning facity Separat surface water Industrial wastewater Other E Private E Municipal E Other View Historical data gt e cM 3 gt Now showing data from 1 June 2012 A xl A Figure 41 Data from 1 June The last two buttons on this panel are the update and the reset button The J Smple Advanced Currently selected compound is BIS unit mgl National limit 75 mgl AR max li min jim Select displayed plants by type y Y Cleaning facity Y Separat surface water Y Industrial wastewater Other _ Select ownership types Private Municipal Other View Historical data Now showing data from 1 April 2012 Update x Bare Figure 42 Data from 1 April update button as mentioned before makes possible to apply the changes to the Update map The reset button restores all changes to default Figure 43 Reset Figure 43 71 4 2 Design
11. HC A Byte of Python 2005 W3C HTML5 Definition complete HTML5 Definition Complete W3C Moves to Interoperability Testing and Performance 17 December 2012 http www w3 org 2012 12 html5 cr accessed January 3 2013 WM data Vejledning i brug af WinSpv4 11 December 2006 84
12. are not aware of the whole process and need to start from the previous step again while Waterfall method does not give such kinds of opportunity 2 2 Database management system DBMS A database is a collection of one or more data files which has integration linkages and cross reference with each other The main advantage of database is that they can be easily organized Software called a database management system DBMS is used to retrieve data Normally DBMS which is a crucial component of most successful GIS are used to store manipulate and retrieve data from a database files that allow users to create edit and update It is also possible to add delete change sort or search in DBMS Longley 2004 Fundamental characteristics of DBMS Database will serve all kinds of individual rather than a single individual There are some fundamental characteristics of DBMS are described below and these factors enhance the efficiency and productivity in data management e The method of data storage can be considered independently of the programs that access the database e A controlled and standardized approach to data input and update can be enforced with appropriate validation checks to ensure data integrity and consistency between data files e Security restrictions on access to specific data subsets can be applied e A consistent approach can be adopted for managing simultaneous multi user read and update operations on specific files or tables
13. codes and names are referring to before the municipal reform in 2007 Therefore the data is joined with a conversion table in order 61 to get the correct municipal names and codes This could just as easily have been done at other points in the process 7 2 Lastly the view created from step 8 is put into a table instead of a view This is done in order to add a spatial index in order to speed up the drawing of the data When the above steps are followed the resulting table will have all the nee ded data structured in a way so it can be easily accessed Measurement Database Newest data Compound 1 data Compound m data Nef Soe Newest Com Newest Com pound 1 data pound m data Total for O Limits data Total with limits for newest data Measurement Database Total with limits for 1 historical iteration ae Newest and Total with limits historical for another O r anc iterations historical together iteration Figure 26 Steps to get to the desired table A flexible view GeoServer offers a service called parametric view The implemented parametric features are e Relate measured value to limit value e Choose compound for visualization e Use custom limit values e Choose a subset of facilities based on facility type and or facility ownership 62 e Choose either newest data or data from up to another predefined list of datetimes The parametric view allows us to enter parame
14. gt suzeme _ Select compound for overview ST Zoomto Denmark E Show wastewater treatment facilities and pipes Show municipal borders Mal for vandets surhedsgrad En neutral opl sning har en pH p 7 En syreoplosning har en pH mellem 1 097 og en basisk opl sning har en pH mellem 7 og 14 x y i 34226 coordinates 20 35016 55 13660 Search for municipality Figure 35 PH chosen as the shown compound Zoom to Denmark Show wastewater treatment sites on Zoom Show municipal borders Figure 36 The selectable layers Underneath the dropdown button there is Zoom to Denmark button when used the application zooms to the initial extent Figure 36 p __ Hvall s O ei Show 1 MN 3 A treatment Figure 37 The corresponding facility to the point of discharge The simple panel also include two check boxes that are positioned under the zoom to Denmark button The first checkbox is Show wastewater treatment facilities and pipes When checked the treatment facilities are displayed as small blue circles and lines connecting the fadlity to the corresponding point of discharge See Figure 37 69 The second checkbox is Show municipal borders and when used a layer with municipalities is added to the map See Figure 38 Figure 38 An example of the municipality borders turned on Using the next tool the opacity slider the opacity of the mun
15. interchange format which is based on JavaScript Programming language as defined in the ECMA European Computer Manufacturers Assodation It is easily understandable JSON is smaller than XML and it is easy for machines to parse and generate as JSON is a native data type Mainly JSON serves as an alternative to the XML format JSON is completely language independent but cooperates with C family languages induding C C C Java JavaScript Perl and Python etc All these properties make JSON an ideal data interchange language Fu and Sun 2011 Example of XML and JSON is given below An XML example lt xmlversion 1 0 encoding UTF 8 gt lt students gt lt student gt lt name gt John lt name gt lt hobby gt Basket Ball lt hobby gt lt student gt lt student gt lt name gt Lisa lt name gt lt hobby gt Movie lt hobby gt lt student gt lt students gt A JSON example students name John hobby Basket Ball 1 name Lisa hobby Movie Python Python is one of the few programming languages which can be used simply and powerfully with both the beginners and experts Swaroop 2005 It is easier to concentrate of problem solution in Python than making the syntax and structure of otherlanguages Python is an easy to leam powerful programming language It has efficient high level data structures and a simple but effective approach to object oriented programming Python s elegant synta
16. interface Fu and Sun 2011 The language tells the web browser to present lay out information text images etc in the browser window The language is a markup language where you markup text in a document with tags to give it a 26 special meaning In that way you add the structure of the document where the markup indicates the different parts of the product For example you can use an opening tag lt html gt and a closing tag lt html gt with the content that the tag is applied to in between them and the slash is the only marker of the closing of the tag Peng and Tsou 2003 Like a tree each element is contained inside a parent element where each element can be spedfied by any number of attributes An example of a HTML structure is seen below Document Structure lt html gt lt head gt lt title gt My First Web Page lt title gt lt head gt lt body bgcolor red gt lt h1 gt This is a header lt h1 gt lt p gt A Paragraph of Text lt p gt lt body gt lt html gt This markup allows letting a web browser display the document in turns because the script tells the web browser how to display this structure Important HTML Tags is lt head gt lt head gt found at the beginning of an html document and will contain information such as the title keywords CSS and Java script information lt body gt lt body gt the substance of your web page is found between these two tags and contains the information yo
17. is wrong one can start again a new approach It opens a door for communicating with all the members in the project including development team project leader and clients In the development process it is possible to change as the method is more flexible Agile Methodology 2012 The agile methodology provides many opportunities for software development throughout the development lifecyde as it follows iterations of the cycle In the agile approach every aspect of the development requirements design etc is followed in every cycle and if the project is stopped then there is a possibility to follow it in another direction Here the development teams have many chances to reach the goal while in Waterfall methods the development teams have only one chance to reach the goal Agile 16 methods reduce both development costs and time to market The development methods help companies to build the right product AgileMethodology 2012 Pros and Cons The Agile methodology Pros Delivers value fast fist iteration work cycle can be demonstrated High flexibility No significant rework Product is tested early because of the short iterations Risk decreased by always having working software Good if end state is unknown May lead to unrealistic expectations Not process orientated which can lead to the lack of documentation Though there are pros and cons for both the two strategies Agile methodology is used widely when the developers
18. the conclusion we have underlined that the web application we have created during this project answers the stated problem fully The used methods support the applicationin a good way However we have stated that the time has made some limitations and further work would improve the system In this section we will describe some development perspectives on the system 7 1 Designing the map We tested different online background map services that could be implemented instead of the very detailed OpenStreetMap symbology For instance we created a Cloudmade map on maps cloudmade com This is a service where different layers can be edited removed and attached to the map We made it totally clean besides from the country borders When zooming in at appropriate levels lakes streams canals etc is visible for the viewer This was not implemented within the timeframe of this project but would be possible if more time was available 7 2 Access to more data As previously noted much of the WinSpv data was skipped and not put to use If a longer implementation period was available it would have been a good idea to look more into this skipped information It could have been assessed which of these data could be implemented visually on the map as colouring or otherwise This accounts for especially for data specific to the measurements Data about quality of the measurement measurement method and measurement uncertainty could be displayed visually in some way
19. the map Here are some examples of geoext elements are e MapPanel element is the most important and used in GeoExt applications Using OpenLayers JavaScript it displays rendered data using popular mapping services as Google Maps or Open Street Map A Map Panel coding example is shown below mapPanel new GeoExt MapPanel title GeoExt MapPanel region center height 400 width 600 map map center new LonLat 146 4 41 6 zoom 7 e LegendPanel element is a panel that shows legends from all the layers in the layer store The legend elements are displayed depending on the type of layer The displayed data can be configured in layer store using the configuration options dynamic filter layerstore or preferredTypes A Legend Panel coding example follows legendPanel new GeoExt LegendPanel defaults 41 labelcls mylabel style padding 5px width 350 autoScroll true region west e Ext Panel element defines the interface of the GeoExt application arranging and putting together all the panels declared and included into Ext Panel An example of Ext Panel is shown below new Ext Panel title GeoExt LegendPanel Demo layout border renderTo view height 400 width 800 tbar new Ext Toolbar 1 items text add remove handler addRemoveLayer text movetop bottom handler moveLayer text togglevis handler toggleVisibility text hide show h
20. the newest date summarize data count occurrences get average number and more e Union Tables can be added together using union If two tables are united all records from the two tables will be put in to one big table with the combined number of entries except for duplicate values that is toinclude duplicate values union all can be used PostGreSQL 9 2 PostGreSQL is an open source object relational database system ORDBMS It runs on all major operating systems induding Linux UNIX AIX BSD HP UX SGI IRIX Mac OS X Solaris Tru64 and Windows PostGreSQL itself follows standards supporting complex queries triggers backup and views among database features Its SQL implementation conforms to the ANSI SQL 2008 standard The software can be easily extended by adding different functions It has native programming interfaces for C C Java Net Perl Python Ruby Tcl ODBC etc PostGreSQL 2012 The PostGresSQL uses a server process and the user client s applications request e A server process It performs database actions from the client side and accepts the connections to the database from the client applications and thus manages database files e The user client s applications request Client applications can be very diverse e g a text oriented tool graphical application web server or a specialized database maintenance tool Some client 21 applications are supplied with the PostGreSQL distribution but most of them are
21. the user select which parts of data he or she wants to have shown in order to prevent distraction and over representation of data e Intuitive controlling The map that can easily be controlled with minimum introduction The cartography and the instruments are all self explanatory e Free and open source usage The selection of software and tools for implementation of the application has been done by prioritizing open source and free selection The only not totally free tool used is Ext js The following functionality has been implemented in order to give the user options for data selection on the map e Choose compound e Custom limits e Selection based on facility types and ownership e Historic data Answering research question 2 Chapter 3 explains how data went from being a raw WinSpv data sheet to being fully functional updatable spatial databases The following steps were executed e Analysis How is data looking and what could be used e Sieving Bad and unused records and data are removed to improve performance and clarity of the data e Refining Data is refined for better usage This includes converting commas to periods and adding IDs 77 e Database Data is stored in a relational database normalization is the key word here e Queries Queries are designed in order to align data in a table suited for interaction between GeoServer and e Updating A script is created that creates new fields in the measurement table a
22. time consuming When the user sends requests for large amounts of data it takes time to send the requested data by the server If the server sends complex data sometimes it is very difficult to process that datasets from the client s side unless it is not powerful and it makes the system very slow The user needs adequate training to process complex datasets On the other hand intemet bandwidth and client computing power hampers the tasks The server cannot send gigabytes of data over internet to perform GIS operations Fu and Sun 2011 23 request amr All processing Client done at client gt ar Applets Figure 8 Example of a client side strategy Foote og Kirvan 2012 Thin client Server side processing of data Server side strategies allow performing most of the tasks by the servers while client do less of the job Users simply send requests to the server via intemet and server does the processing through map generation and analyzing data It returns a response to the client with the output information The client s browser displays the result information Server side architecture follows these steps First the client sends request to the servers Then the server processes requests and sends information Then the output required by the client is returned to the server and send response to the client The last step is that client can see the information is their browser Server side strategies have some advantages There
23. 0 All facilities l z u a sSpno ooo o o 1 march00 00 for another poi time iteration n 1 march00 00 e Other E i j datetimes Figure 25 Desired look of the final table The way this is achieved is by splitting the data up in several ways and then combining it again like shown in Figure 25 In the process more than 100 views are created with exerts of data from the measurement database The number of facilities is called n and the number of compounds is called m The following steps are done to get a suitable result Data must be split on the compounds so that there is one view per compound Data not relevant to the historical datetime must be removed This resultsin m n records The two above must be joinedin one view per compound This results in views with n records FPwWwNn rR The views from step 3 must be joined together in a full join also adding the facility database This allows the structure where the compounds appear as different columns for the same fadlity This results a view with n records 5 The view from step 4is then joined together with the limits table 6 Then step 2 5is repeated with another historical datatime for as many iterations as is wanted 7 All the historical datetime iterations are then added together on top of each other This results in a view with n m 7 1 As mentioned in3 3 Data the facilities database municipal
24. 0 Total N 1 Till b DS EN ISO 11905 1 mg l 0 Total N 1 Afi b DS EN ISO 11905 1 mg l 0 Total N 1 Afi b DS EN ISO 11905 1 mg l 0 Total N 1 Till b DS EN ISO 11905 1 mg l Table 4 The first seven rows of the original data 58 00000000 0 NULL 0 NULL 0 NULL 0 NULL 0 NULL 0 NULL 0 NULL 0 NULL Drop null values and other odd values At first glance some gaps in the data can be found The gaps are represented by the values NULL or just Some fields are critical and some are not It is therefore necessary to decide which fields are critical and then filter out bad records Python scripting is used to do this by reading each line and testing whether they meet the requirements Critical Keep Loose Facility Name Municipality Number Notes Last Update Type of discharge Contact Person DS year of requirement FLETBIS Purpose of measurement Ownership Telephone Fax Opt out water Attribute UTM_N Facility Adress Date created Rain mm Detection limit UTM_E Facility Postal Code Date demolished MINANT_VANDF Notes UTM_N Discharge Mobile Catchment MINANT_RES Quality UTM_E Discharge E mail SYS34_X facility UNDERTRYK_REVPRV Uncertainty Timestamp SYS34_Y Facility UNDERTRYK_KRVPRV Man Opt out Result SYS34_X Discharge Use of Trapez SYS Opt out Compound Short Form SYS34_Y Discharge WaterTime Series Opt out Place HYDROL_REF Use Average Opt out compound Unit Distance STOFMET1 MAN opt out compound Discharge number STOFMET2 Number per Unit M
25. 2th 2011 to January 8th 2013 The project is furthermore written based on the M Sc Programme in Geoinformatics study guide for 7th semester In the project period the courses Spatial Data Infrastructure and Geospatial Information Technology has introduced us to databases programming and Web GIS Dedsions about which programs to use have been based upon experienced gained during these courses The project group s main supervisor is Morten Fuglsang at Aalborg University Reading advice The reading advice is prepared to simplify the flow for the reader through the report Source references The Chicago referencing style is used to source our references It is an author date system that consists of two parts the citation in the text and a bibliography at the end of the report The authors surname and the year of publication appear in the citation in the text The author s surname other names as initials year of publication title edition and place of publication are shown in the more detailed bibliography Figure 1 shows how the source references are managed in the citationin the text and the bibliography Author Surname s Page s Fu and Sun 2011 34 35 Year of publication Author s Title Place of Publication Publisher Fu P and J Sun 2011 Web GIS Principles and Applications 1st ed Redlands ESRI Press Year of publication Edition Figure 1 Examples of the Chicago method to the left is seen the citation wi
26. 401 727150 6173401 727150 6178401 727150 6178401 727150 6178401 OPLANDNAVN UTM_N_ANLAEG UTM_E_ANLAEG UTM_N_UDLOB UTM_E_UDLOB 729915 729915 729915 729915 729915 729915 729915 729915 AFSTAND BEMAERKNINGER FLETBIS FRAVALG_VAND REGN_MM MINANT_VANDF MINANT_RES UNDERTRYK_REVPRV NULL NULL 0 0 NULL NULL NULL 0 0 NULL NULL NULL 0 0 NULL NULL NULL 0 0 NULL NULL NULL 0 0 NULL NULL NULL 0 0 NULL NULL NULL 0 0 NULL NULL NULL 0 0 NULL UNDERTRYK_KRVPRVY ANVEND_TRAPEZ_VED VANDTIDSSERIE ANVENDMIDDELTAL 0 NULL W AA 0 NULL lu AA 0 NULL W AA 0 NULL W AA 0 NULL W AA 0 NULL W AA 0 NULL W AA 0 NULL W AA 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 STOFMET1 GNS 18 09 2012 K GNS 18 09 2012 K GNS 18 09 2012 K GNS 18 09 2012 K GNS 18 09 2012 K GNS 18 09 2012 K GNS 18 09 2012 K GNS 18 09 2012 K 00000000 SIDST_OPDATERET PROEVEFORMAAL STARTDATOTID ATTRIBUT RESULTAT DETEKTGRNS KVALKLASSE MAN_FRAVALG SYS _FRAVALG FRAVALGT MAN_FRAVALG STOF 07 02 2012 NULL 7 3 0 05 NULL NULL 21 02 2012 NULL 33 0 05 NULL NULL 21 02 2012 NULL 5 1 0 05 NULL NULL 05 03 2012 NULL 54 0 05 NULL NULL 19 03 2012 NULL 51 0 05 NULL NULL 19 03 2012 NULL 3 6 0 05 NULL NULL 12 04 2012 NULL 5 3 0 05 NULL NULL 16 04 2012 NULL 53 0 05 NULL NULL FRAVALGT_STOF KORT_FORM ENHED Sted Metode Enhed 0 Total N 1 Afi b DS EN ISO 11905 1 mg l 0 TotaLN 1 Till b DS EN ISO 11905 1 mg l 0 Total N 1 Afi b DS EN ISO 11905 1 mg l 0 Total N 1 Afi b DS EN ISO 11905 1 mg l
27. Abstract and a Graphic with one defined colour size and shape More advanced styling available as well More colours can be defined corresponding to attributes or corresponding to a certain zoom level SLD can be divided in rules and each rule can have a filter generated in the attributes This filter describes which records to render Multiple symbolizers describe how those records are rendered Open Geospatial Consortium Inc 2007 Many examples are found through the SLD Cook Book Pumphrey 2012 But the frame of the possibilities of SLD is much more widespread than the content of this book The legend is created through the SLD as well Each time there is a call to the WMS the legend is refreshed and shows all graphic styles that are shown in the certain session Open Geospatial Consortium Inc 2007 2 6 Cartography theory Information on a map is a representation of the real world It is an attempt to reproduce information on a way that makes the information understandable for the consumer To make information understandable is an infinite discussion on what understandable is Traffic lights show information on when to go and when not to go with the colours of red and green The problem with this is that one in every 10 persons are colour blind on red and or green Brodersen 2008 With this in mind it would be obvious to use other colours But what colours can be understood by the majority as go and not go instead of green and red To man
28. D r ETE E EE E E EEI EA EEI E E E EE EE 56 A RESUIE OO 65 AI FUNC OMANI DY a 65 A 2 A ua iwecdubedbede lees E R E E a E E E sesh E a EE EE unde EEE EEE EES 72 A NS 74 A NN 74 A Ne 75 SS eo lor Lo y EE E ccs A E E vung cua veedecoes Saccue vans cua ndeccabvaad gun ane get E eat lt danescecees 75 SA Aglle Vs Wat taller dador doo ia Adidas didas E ao oia S 76 5 6 Answering research QUEstiONS cccooonccccccnonononononcnonannnnnonannnnnonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnonannnnnnnannnnnnnnioss 77 A cic dccccccciteeccucevcsdcesstes T E E E E TE E E 79 AO A A 80 T ALDE SIG MINE TNE Murcia 80 7 2 ACCESS LO MOE 80 7 3 Improve the performance and interoperability oocccocoooccnnnonncnnnonancnnnnnnncnnonancnnncnnccnnnnnnnoss 80 7 4 Shortcomings of the applicatiON ooocccnccoooncnnnoncnnncnnnnnnnnnnacnnnnnnnnnnnnnnnnnnnnnnnnnnonnncnnnnnnncnnnonaness 81 BibliOgraphAy sicscecvecssicetdececeseecveatececsieestesecnestecesteassveesssecetsobesvestansscececessvesssbedecbensscesnsaseceisebsssacseetesreeness 83 1 Introduction WebGIS which is a combination of web and geographic information systems has grown rapidly after its origin of development in 1993 Fu and Sun 2011 From then it gained huge popularity as people can use GIS from the web The intemet browsers have access to GIS applications without buying software while map services allow GIS applications without hosting them locally to have the latest updates Often a client
29. GIS NCGIA Core Curriculum in GlScience Retrieved on 15 12 2012 from http www ncgia ucsb edu giscc units u133 u133 html 2012 Fu Pinde and Jiulin Sun Web GIS principles and applications California ESRI press 2011 GeoServer SQL Views GeoServer 2 3 x User Manual GeoServer org 17 December 2012 http docs geoserver org latest en user data database sqlview html accessed December 17 2012 GeoServerA Whatis GeoServer Retrieved on 12 12 2012 from http geoserver org display GEOS What is GeoServer 2012 Gosnell Denise Professional Development with Web APIs Indianapolis Indiana 2005 Horsens Vand A S Analyseveerdier for renset spildevand Horsens 2011 Kunen Isaac Introduction to Spatial Coordinate Systems Flat Maps for a Round Planet 07 2008 http msdn microsoft com en us library cc749633 v sql 100 aspx accessed 01 06 2013 Longley Paul A Geographic Information Systems and Science ISBN 978 0 470987001 3 USA John Wiley amp Sons 2005 Milj ministeriet Spildevandsbekendtg relsen Bekendtg relse om spildevandstilladelser m v efter miljgbeskyttelseslovens kapitel 3 og 41 retsinformation dk 11 December 2011 83 OGC Open Geospatial consortium Web Map Service retrieved on 12 12 2012 from http www opengeospatial org standards wms 2012 Open Geospatial Consortium Inc Styled Layer Descriptor profile of the Web Map Service Implementation Specification Specification Open Geos
30. GeoServerA 2012 Stores contain geographic data in GeoServer It contains specific data sources that GeoServer supports Like databases which contain many tables stores also contain many layers Stores must be associated with a workspace GeoServerA 2012 Like stores a layer must be associated with a workspace A layer is a collection of geospatial features or a coverage which is also the smallest grouping of geospatial data It contains single type of data points lines polygons raster etc having a single identifiable content type e g roads lakes etc It corresponds to a table or view from database GeoServer stores information which is associated with a layer such as projection information bounding box associated styles etc GeoServerA 2012 A layer group is a collection of layers which makes it possible to request multiple layers with a single WMS A layer group contains information about the given layers order projection associated styles etc This information can be different from the defaults for each individual layer Each layer group must be associated with a workspace Every layer must be associated with at least one style and GeoServer recognizes styles in Styled Layer Descriptor SLD GeoServerA 2012 A style is a visualization directive for rendering geographic data A style can contain rules for colour shape and size along with logic including attribute based rules and zoom level based rules GeoServerA 2012
31. MTVER REQUEST map LAYERS layer_list STYLES style_list SRS srs_identifier BBOX xmin ymin xmax ymax WIDTH output_width HEIGHT output_height TRANSPARET true_or_false BGCOLOR color_value Description URL prefix of the server Request version required Request name required Comma separated list of one or more map layers required Comma separated list of one rendering style per requested layer required Spatial reference system SRS required Bounding box corners lower left upper right in SRS units required Width in pixels of map picture required Height in pixels of map picture required TRUE FALSE If TRUE then the background color of the picture is to be made transparent if the image format supports transparency optional default FALSE A hexadecimal red green blue color value Oxrrggbb for the background color optional default OxFFFFFF Table 1 According to OGC 2000 Map Request Interfaces Peng and Tsou 2003 196 GetFeature The feature request interfaces identify the request mechanisms for map contents and feature attributes It answers the queries regarding what map layer is being queried and the location of places on the map showing the coordinates Peng and Tsou 2003 Table 2 shows the elements of feature request interfaces URL Component http server_address path script WMTVER REQUEST feature_info map request copy QUERY_LAYERS layer_list INFO_FORMAT output
32. Open Street Map 47 Web architecture As the system design shown in Figure 17 System design of the project suggests most of the work is done on the server side The layers are communication between GeoServer and the databases which is hosted by a server The background map is also hosted from a server this is just externally cloud based But the system is still a hybrid because a few layers are operated on the client side These are WFS layers used for the operation of controls and GeocoderComboBox These WFS layers are very lightweight and will not be saved anywhere outside the application Therefore the application can be described as a client server hybrid strategy albeit much closer to a thin client than a thick dient Database structure design In the following the design of the databases serving the WinSpv data will be described As previously described a sensible database design is essential for speed and flexibility For this purpose a relational database is chosen for the database design In the original WinSpv table there were a lot of abundances and not all the needed data So a normalization process and a database design were obvious choices The WinSpv holds both data about the measurements and the facilities so an obvious start is to split this up and create ids as primary keys To see an example of the WinSpv table see the section Preparation Facility data Measurements opens Measurement data Facilitie
33. The two methods are the waterfall and the agile methodologies The strategies are needed to make the process more functional and to perform in a better way The strategies also lower cost including time and money Two strategies which will be discussed in the following section have pros and cons which will also be considered The waterfall method In the waterfall software development all the requirements are gathered at the beginning which is followed by a design and implementation phase It is a sequential and phase wise method that does not leave opportunity for going back and revisiting all the requirements It was first introduced in 1970 The waterfall method is a linear and sequential approach in which separate teams are appointed in each stage to ensure greater project and deadline control The project team first analyses then determines and prioritizes business requirements needs In the design phase business requirements are translated into IT solutions and a decision taken about which underlying technology i e COBOL Java or Visual Basic etc is to be used Once processes are defined and online layouts built code implementation takes place The next stage of data conversion evolves into a fully tested solution for implementation and testing for evaluation by the end user The last and final stage involves evaluation and maintenance with the latter ensuring everything runs smoothly Buzzle 2012 Figure 3 General Overview Water
34. We found examples on this and it would have been essential to test these things If only time was not a limitation 80 The application could have been developed in HTML5 In this way we would have been able to develop the application to be compatible with tablet and smart phones This approach should be considered if making the application as a saleable application 7 4 Shortcomings of the application As previously mentioned the implementation of the described application has been constrained by time In this section it will be described where the application fall short where more time for implementation would have been used to improve the application There are three main shortcomings of the application as described in the previous chapter e Too many fadlities and pipes e Selection code notimplemented e Performance and drawing Facilities and pipes As explained the measurements are represented at the point of discharge on the map The graphical addition of facility sites and pipes are added as an optional graphical layer with no functionality This is how it should be The problem is that while points of discharge with no measurement data for a special selection will not appear on the map the facilities and the pipes will appear for all facilities disregarding the fact that there is no data ase hy AN oe h r 4 7 Hah f Hesingo e f 912 hns E Gette O a IA i Roskilde A Wr N j
35. WebGIS solution for wastewater facilities in Denmark Fall 2012 Geoinformatics Aalborg University Copenhagen Aalborg University Copenhagen Semester 1 semester Title WebGIS solution for wastewater facilities in Denmark Theme Gl Technology and Information System Project period 2012 September 2th 2013 January 8th Submission date 2013 January 8th Abstract Supervisor Morten Fuglsang This project concerns creation of web application by adequate Project group 2 roe searching possibility for Attendees wastewater in whole Denmark where we added several _ O A A functionalities with advanced Lars Kristian Engelsby Hansen 20120573 search options We identified two kinds of user groups who will use the application These groups are the professional and the citizens Vlad Hosu 20120203 We structured our project work by following agile method We used A A E E different kinds of platforms for the Meherun Nahar 20111794 project like python programming PostGreSQL OpenLayers GeoExt etc Number of copies 7 copies Number of pages 84 pages In appendices 62 pages Copyright O 2012 This report and attached material cannot be published without the authors written acceptance Preface This project is drafted by project group which consists of four students from Aalborg University The project is emanating from the theme GI Technology and Information System and is developed in the period of September
36. _format FEATURE_COUNT number X pixel_column Y pixel_row Description URL prefix of the server Request version required Request name required Comma separated list of one or more map layers required Return format of feature information optional How many features to return information about optional X coordinate in pixels of feature measured from upper left corner 0 Y coordinate in pixels of feature measured from upper left corner 0 Table 2 According to OGC 2005 Feature request Interfaces Peng and Tsou 2003 197 GetCapabilities The capabilities request interfaces is used to provide extensive map services like catalogue services or metadata queries For example to ask a map server about its holdings the URI parameters can be induded in the capabilities requests such as database Colorado California Peng and Tsou 2003 35 URL Component Description http server_address path script URL prefix of the server WMTVER Request version required REQUEST capabilities Request name required Table 3 According to OGC 2005 Capabilities Request Interfaces Peng and Tsou 2003 198 Web Feature Service WFS WFS provide specified geographic features in vector format for user interaction by following OGC standard WFS helps clients to perform different kinds of operations including insert update delete and query for geospatial feature data residing on the server According to OGC 2005 WFS defines the fol
37. acility The data part includes information about measurements of different compounds on the local facility This part is updated locally at the facility but the municipality is responsible for verifying the data This division in responsibility is available in Dataansvarsaftalen for punktkilder which is approved in a partnership between the Danish EPA Local Government Denmark KL and Danish Regions Danish Environmental Protection Agency 2011 Each record has two coordinate sets One for the wastewater facility referred to as in and one for the corresponding point of discharge There are no data for the pipe between the two points but a straight line between the two corresponding point will be able toillustrate the connection The system is meant to be public because data is not linked to any privacy restrictions However users with a professional or interest for wastewater are most likely to use the web application These are people that have some knowledge about the data Primary professionals working with Wastewater are the target group 1 1 Problem Statement In this report we want to test the possibilities of making a WebGIS application by designing it in order to interactively display and make searchable wastewater facilities and their measurements By creating such an application it is possible to spread knowledge and information easier Clients who need wastewater facility related knowledge can get their required data
38. age all the possibilities there are available within the visualization of information representation on a map Brodersen 2008 made a model to run through during the developing progress of the design of the map In Figure 15 the model is presented The model contains five basic elements e Values are about the values that justifies the project Who is the producer and what will he use the project for e Content is the content that enables that the user can solve his tasks e Apparatus is the part that the user through the use gets in contact with the content e Interaction is about how the user through the apparatus gets in contact with the content e Expressed information is what the user sees 43 Values Apparatus Content Interaction form user s conduct Expressed information Figure 15 Geo communication and information design model BrodersenA 2008 Brodersen 2008 distinguish between four tools within the expressed information The laws of gestalt are a main tool It is about how a visual impression is perceived An example could be a consideration about how we would know that a green polygon necessarily means a forest on a map In a visual hierarchy it is determined which elements are visually dominating and important Brodersen 2008 tells for instance that warm intense and sharp colours symbolize the point in the map while they seem strongest The level of abstraction is a matter of preferences among the users It is o
39. an be accepted with different regex 63 Either mal ormal2 are always set to zero depending on whether parsed float custom limits are used or limit values from the table are used The same logic applies to mil andmil2 The advantages of this calculation are thatif result is higher than 1 some limit is exceeded and vice versa And that when a compound like lead or any other except pH enters the calculation it will reduce to l E f Beat The disadvantages are that pH values will always appear very close to the limit values which will affect the possibilities of common visualization And minimum limit exceedences are weighed over maximum limit exceedences The calculation above covers the three first points of what the query should be able to do The where clause of the query is where the actual selection is done It looks like this WHERE types AND Sownership AND hist hist specname muni where types is an expression that contains selection of the wanted facility types ownership is very similar just handling ownership types Types and ownership are integer columns and can be selected like type 2 or type 4 hist is the column in the table keeping track of which historical iteration is shown Specname is for selecting a single facility by its name and muni is for selecting facility in a specific municipality If a spedfic municipality is wanted then muni can be set to AND m_name H rsholm Pu Kom
40. andler updateHideInLegend text legendurl handler updatelegendUrl items legendPanel mapPanel Styling the WMS Styled Layer Descriptor SLD extends the WMS standard to allow user defined symbolization and colouring of geographic features Open Geospatial Consortium 2012 SLD is an OGC styling language standard that both the client and server can understand It indudes a StyledLayerDescriptor XML element that contains a sequence of styled layer definitions Open Geospatial Consortium Inc 2007 Here is a simple example of a SLD that defines the style of a point lt NamedLayer gt lt Name gt Default Point lt Name gt lt UserStyle gt lt Title gt Point feature lt Title gt lt Abstract gt This style styles a point feature with red squares lt Abstract gt lt FeatureTypeStyle gt lt Rule gt lt Name gt Rule 1 lt Name gt lt Title gt RedS quare lt Title gt lt Abstract gt A red fill of squares with a pixel size on6 lt Abstract gt lt PointS ymbolizer gt lt Graphic gt lt Mark gt lt WellKnownName gt square lt We11KnownName gt lt Fill gt lt CssParameter name fil1 gt FFO000 lt CssParameter gt lt Fill gt lt Mark gt lt Size gt 6 lt Size gt lt Graphic gt 42 lt PointSymbolizer gt lt Rule gt lt FeatureTypeStyle gt lt UserSt yle gt lt NamedLayer gt lt StyledLayerDescriptor gt This example is simple with the following elements Name Title
41. ant to see dear and apparent munidpality borders Furthermore they want to see the apparent municipality borders at any zoom level We made the borders in a black and thick line no matter the zoom level See Figure 47 and Figure 48 to see the borders A Figure 47 The municipality borders at a close zoom Figure 48 The municipality borders at a large zoom As with the borders the facilities and the pipes were made selectable for the user The facilities and pipes are blue points and the pipes are a corresponding slightly lighter blue Both with the same size at any zoom level due to the fact that they are less important than the points of discharge Examples of the pipes and facilities are showed in Figure 49 and Figure 50 e Sam gt a e o e E El 2 e a a e i e N 2 Y A Figure 49 The lines that represent the pipes Figure 50 The points that represent the wastewater facilities 73 5 Discussion In this Chapter the choices and outputs that has lead to the results described in the last chapter will be discussed For obvious reasons not all alternatives can be discussed thoroughly and most alternatives are not mentioned prior to this section but still some choices are worth a discussion and those are mentioned in the following A choice that may not seem like an actual choice because it lies so early in the process of forming an idea that will later become a web application is the choice to represent data in an interactiv
42. ap Section STOFMET3 Method Table 5 Choices concerning use of original data Critical is data that must not be missing keep is data kept disregarding quality and loose is data not used Itis obvious from table 5 that a lot more information could be extracted from the data and possibly put to good use This topicis discussed in the 7 Perspectives Another important selection were of the compounds There was a total of 196 different compounds measured ranging from Total N measured 9634 times to several compounds only measured one time To limit the number of compounds only compounds with Danish legal limit values Milj ministeriet 2011 and compounds measured at Horsens Centralanlaeg Horsens Vand A S 2011 were chosen Having done these filters the data ended up having around 44 000 records left corresponding to about 75 of the data Limit values In order to have a meaningful display of the data an option is to relate measured values to limit values this way it can be shown whether the limits are exceeded or not on the map Some limit values are national and some limit values are local and spedfic to facilities Data on local limit values are not imme diately available so a table was created with the national limits for the compounds where national limits were available and the rest was filled out with the limits of Horsens Centralanleeg This means that the visual result for most of the measured compounds is not corresponding to real val
43. by searching Moreover WebGIS application will help for further research fadlities With these thoughts in our minds we decided our problem statement to be 10 How can an open source WebGIS application be designed in order to interactively display and make wastewater facilities and their measurements searchable To make the problem statement more concrete we made three research questions which will further guide us to follow the appropriate way The three research questions are e What types of functions could be developed to support the use of the data in the application e How can data be gathered refined and stored to fit into the application functions e Which platforms should be used in the application 1 2 Report structure Our report consists of following sections e Introduction e Theory e Methodology e Result e Discussion e Conclusion e Perspectives We conducted out report by following three phases Phase 1 Description of the Phase 2 Data analysis and Phase 3 Discussion and project implementation evaluation e Introduction e Methodology e Discussion e Theory Result e Conclusion e Perspectives Figure 2 Structure of the report Phase 1 describes about the project It consists of an introductory part and theory section In the introductory part we describe the background of the project It is followed by a problem statement and three research questions and limitations that we face while conducting the project
44. cape It primarily runs inside the web browsers JavaScript is simple so that both professional and non professional programmers can deal with it JavaScript is safe because of its limitation to the access of the client s computer OpenLayers uses JavaScript knowledge of java code construction is required However usually it is enough just to modify existing code Java needs to be enabled in the browser so one need to bear in mind that users not necessarily have java either the java application should be an enhancement of the page or there should be relevant information to the installation of java Peng and Tsou 2003 JavaScript Basics JavaScript is primarily used in the form of client side JavaScript It allows different applications of features and user interfaces for dynamic websites The code consists of objects that have properties and methods to perform different actions The code consists of objects each of which have properties and methods All code stays between lt script gt tags in HTML documents An important part of JavaScripting is creating functions for use later in the code An example could be this function syntaxer a call var t for var i 0 i lt a length i t t callt a i or t2 t substring 0 t length 4 return t2 Here a function called syntaxer is defined It should have two arguments a list a and a string call and t2 which is a string is w
45. cess to follow Again we do not have experience to fulfil the demands of waterfall methods We followed this approach for the project as we had very limited time period Therefore we followed some 76 iteration Firstly we transformed xls database to dbf and imported it to PgAdmin Then we set up GeoServer and developed html webpage application which was tested if it is working or not We found that our application is working Then we developed our second iteration by adding more GeoExt components like updating compounds database limits etc Finally we did third iterations for some improvements of the application We already induded update button We added a reset button to get back to the default values In this phase we also added some advanced search like the municipalities and facility search Then we run the program and we achieved our expected results 5 6 Answering research questions The research questions as presented in 1 1 Problem Statement section sounds as follows e What types of functions could be developed to support the use of the data in the application e How can data be gathered refined and stored to fit into the application functions e Which platforms should be usedin the application Answering Research question 1 A web application has been created in order to comply with the user requirements The most important features of the application are e Interactive data representation Data is shown little at a time letting
46. ch is usually represented in longitude and latitude Here the map projections become very 44 important in building a link between the two types of coordination systems The principle of projection is to transform spherical surface into plane through mathematical expressions Most of the GIS projects use data from different sources that do not have the same coordination system so they have to be projected or re projected before using Longley 2004 Geographic Coordinate Systems The location is defined on Earth s surface by latitude and longitude The representation of geographic coordinates is made with respect to Greenwich and The Royal Observatory The geographic coordinates notation is such as the plane coordinates with longitude as x and latitude as y the coordinates can be either positive or negative depending on the reference lines The longitude values that are measured in the eastern hemisphere are positive and negative in westem It is the same with latitude the values are positive in the north and negative in south Longley 2004 When mapping spatial features a model that approximates the surface of Earth is needed The sphere is the simplest model that the Earth can be represented on but this planet is not perfectly circular so a better approximation is a spheroid or an ellipsoid Longley 2004 The datum is used to create a reference for the geographic coordinates and it consists of an origin and the parameters of the selected e
47. check if the system meets the requirements BuzzleB 2012 14 Agile methodology Like waterfall the agile methodology is also used in software development It is an alternative to traditional project development It follows iterative work flows in the response of unpredictability of software building AgileMethodology 2012 Dr Winston Royce mentioned some issues regarding traditional software development in a paper entitled Managing the Development of Large Software Systems in 1970 He presented that projects could be developed in a sequential basis Developers first fulfil all the requirements then carry out every phase But due to some shortcomings of the traditional system in February 2001 17 software developers decided to make new methods for software development They were agreed on agile methodology and they published the manifesto for agile software development AgileMethodology 2012 Agile manifesto includes 12 principles e Our highest priority is to satisfy the customer through early and continuous delivery of valuable software e Welcome changing requirements even late in development Agile processes harness change for the customer s competitive advantage e Deliver working software frequently from a couple of weeks to a couple of months with a preference to the shorter timescale e Business people and developers must work together daily throughout the project e Build projects around motivated individuals Give th
48. common web based GIS System with Getcapabilities server Peng and Tsou 2003 168 Map Servers Application Servers Open Geospatial Consortium OGC Standards The Open Geospatial Consortium OGC consists of 483 companies govemment agencies and universities that have mutual understandings to develop publicly available interface standards OGC standards support 32 interoperable solution and empower technology developers to make complex spatial information and services accessible and useful with all kinds of applications The main purpose of OGC is to serve as a global forum for the collaboration of developers and users of spatial data products and services and to advance the development of international standards for geospatial interoperability One of the main goals of OGC is to provide guidelines for internet GIS so it can be communicable with others OpenGeospatialConsortium 2013 The interoperability program of OGC covers wide range of areas from geospatial data to geospatial processing Web mapping is one of them The OpenGIS Web Map Service WMS interface implementation specification was published in April 2000 which focuses on how to describe a Web map server and map services with standardized URI syntaxes and semantics WMS operations can be done by submitting requests to the web browser in the form of Uniform Resource Locators URLs WMS implementation interface spedfication indicates that WMS should be able to do three tasks produc
49. cond user groups the access to the software is not the biggest concern but for the general public the installation would be a barrier Also the fact that the application is not limited by being a browser application attributed to this choice As described in the theory section there are two kinds of approaches regarding clients thick and thin client In case of thin client client does not have anything to do like editing deleting etc They can send request to the server while server processes their request and they get back the result On the other hand thick clients get the opportunity to edit something when they send request to the server and server processes the request It is not user friendly to be exclusively thin or thick client In our case we combined both the approaches and both the server and client can process the request as we used wms and wfs for processing our application JavaScript is used in order to give the web application rich content Mainly in order to have as a part of the web page and also to have user inputs that can communicate with the map elements This might be doable in other ways But due to time constraints only JavaScript and were tested and proved useful and not limiting Ext is only partly open source It can be used freely if it is for personal educational or open source purposes If ext is used commerdally a license fee must be paid Sencha 2012 This application is indeed created for educational use t
50. creating new documents 25 DELETE will ask the server to delete the information corresponding to the given URL POST creates a new object or appends information linked to the specified object identified by a URL LINK links an existing object to the specified object UNLINK removes link information from an object Peng and Tsou 2003 As HTTP includes all the methods described above it would be an easier task for the web browser to communicate with the web server If the user enters file requests by typing URL or by clicking on a hypertext link the browser builds an HTTP request e g GET HEAD or PUT and sends it to the web server HTTP daemon receives the request and based on the HTTP methods returns the requested file to web browser Once the requested file is returned to the web browser the communication between the web browser and web server is done Peng and Tsou 2003 API Application Programming Interface API is a service delivered by a company who wants developers and users to build applications on top of their product Gosnell 2005 refers to companies as Google eBay Amazon MapPoint and FedEx who have open APIs This is developed to ensure that website developers easily can incorporate the content from the API to the web pages Technically speaking it is a protocol that allows some software to interact with another piece of software When accessing an application that contains one or more API the API makes a call to its or
51. ct oriented Relational Database Management System RDBMS In the relational databases data is connected in different files by common key field In the relational databases data is stored in different tables having uniquely identified key fields Each relation is composed of tables attributes or fields It is not necessary for the users to know how the data is stored in the system because data exists independently in a relational database In relational databases tables or files filled with data are called relations and columns are referred to as attributes or fields A Relational Database Management System RDBMS is a software program used for data creation maintenance modification and manipulation in a relational database Relational databases are more flexible than any other databases Longley 2004 The relational database is popular due to two reasons Relational databases do not require training They can be used with little or no training Another reason is that database entries can be modified without redefining the entire structure The disadvantage of this method is that it takes more searching time for data than if other methods are used The relational DBMS is the dominating DBMS Anfindsen 1993 41 even though this source is quite old and the world of databases moves fast this statementis still relevant Hierarchical Database Management System HDBMS The hierarchical DBMS gets its name from the fact that it stores data hierarch
52. d have been relevant to add in the information box about the facility were not chosen because of too many NULL values This is true for instance for the catchment area Oplandsnavn or the local rainfall Regn_mm Through an agile approach we discovered the relevant data with an acceptable quality Every time we ran through an attribute and accepted it for our data model we rethought the data model and renewed it if it was necessary We developed four databases with relevant attributes The IR diagram helped us getting the overview of the databases and to see it in a larger perspective We discovered on an early stage that we due to the agile approach would edit the input to the databases many times An approach to edit the table could have been to use Excel to delete attributes rename attributes remove bad values etc But the Excel approach would be too time consuming with the often repeatable edits Instead we chose to use scripting so all our commandos where gathered and processed at once We made an effort in getting the commands to work in the script but it was definitely worth it to get it work This will also help processing newer extractions of the WinSpv database in the future A number of database approaches was identified in the theory section Each having advantages and disadvantages depending on the use of the database The hierarchal database for instance is suitable for libraries where one category has many books but many books canno
53. developed by the users A typical client server application is typically on different hosts which must communicate via Internet The software can handle multiple connections and therefore the master server is always opened to run client requests for a connection We use the PostGreSQL as our database management system and let the PostGreSQL database load data to the server GeoServer For this purpose we install an application called PostGIS to the software It is an application which makes PostGreSQL support geographical data PostGreSQL is a well established database program the first Postgre95 release 0 01 was released the 01 05 1995 The 9 2 1 version was released at 24 09 2012 and is a stable version working on desktops with Windows 7 OS PostGreSQL 2012 2 3 Web Architecture In the following section the most important components of the webGIS will be discussed Clients and servers are the two components where the interaction is necessary Clients send requests to the servers and servers responds toit HTTP acts as glue between the dient and server Client Server The client server model is an approach to computer network programming The approach assigns either the client role or the server role to a computer in a network The server is a computer that shares its resources The client is a computer that creates contact to a server in order to make use of the resources from the server In figure 6 is an example of the client server mod
54. e knowledge of code construction from the previous course is required OpenLayers 2012 An OpenLayers Map stores information about the default projection extents units and so on of the map Data is displayed within map via Layer and a Layer is just an information source for data about how OpenLayers should request data and display it In order to build OpenLayers viewer we need to craft HTML to be seen by the viewer and a map can be put inside any block level element This means that we can put a map in almost any HTML element on a page One is required to include a script tag pointing to the OpenLayers library to a single level element OpenLayers 2012 It is not always necessary for the location of the library to point to the js file on the OpenLayers server We can download the full code and run it locally by using the script src equal to the location of the library on the local hard drive OpenLayers 2012 Creating maps with the OpenLayers The following steps are needed to create a web application 1 Link to the OpenLayers library files 2 Create a HTML file that will hold the script 3 Create a map object 4 Create a layer object 5 Add the layer to the map 6 Define the maps extent The basics Code lt DOCTYPE html gt lt htmllang en gt lt head gt lt metacharset utf 8 gt lt title gt My Map lt title gt lt scripttype text javascript src 2 11 js gt lt script gt lt scripttype text javascri
55. e map Data was originally presented in an excel table and this could be visualized without using a map It could have been done with charts leaving out the geographic aspect This leads to a fundamental question of this project Why is the geography relevant The geography might only be relevant for some users maybe a user want to check the user s neighbourhood but does not know the name of nearby wastewater facilities But other users might not need this information One could also question the need for an interactive data representation The data could have also been shown using static maps The advantage of an interactive map is that it can be used for several things as one product If data changes or simply when data updates new maps do not need to be produced Whether the user needs the geographical information or not both specific data can be viewed by clicking and general impressions of the data the user can get quickly by viewing the map The interactive element gives the users many more options and expands the possible application of the data for people without knowledge about GIS 5 1 Data When viewing the original raw data one is struck by the vastness of the data Each record represented a measurement of one compound on one fadlity and each record have more than 60 attributes This demanded certain knowledge about the data due to relevance Another issue was the data quality for some of the attributes Several attributes that woul
56. e maps answer queries and tells other programs about the map Peng and Tsou 2003 OGC also provides standards for Web Feature Service WFS WFS not only shares data but it also uses File Transfer Protocol FTP It allows clients to retrieve and modify data In ISO 19119 the WFS is primarily a feature access service which also includes elements of a feature type service a coordinate conversion transformation service and geographic format conversion service OpenGeospatialConsortium 2013 Web Map Service WMS Web Map Service WMS provides HTTP interface to fulfil the request of a client for geographic map services WMS provides the interface with geo registered map images from different databases as JPEG PNG or another format This image is then further viewed in the web browser The interface also provides transparent images so that layers from multiple servers can be joined OGC 2012 Mainly WMS focuses on describing a web map server and map services with standardized URI syntaxes and semantics considering three major tasks It is needed to mention here that a URI is a short string that is used to identify resources in the web Therefore WMS should be able to e Produce a map as a picture as a series of graphical elements or as a packaged set of geographic feature data e Answer basic queries about the content of the map e Tell other programs those maps it can produce and which of those can be queried further Peng and Tsou 2003 192
57. e the professionals are considered to do searches depending on their aim 3 2 Implementation The implementation part is where all comes together The theory is implemented through methodology using the data The project idea is to create a WebGIS application and is described in the following steps 49 e System implementation e User interface design System implementation Agile implementation process When the project work started the main approach of the work was that which approach it will follow In the theory section two strategies are described Both of the two strategies have pros and cons Based on these strengths and weaknesses the approach of the project is decided Waterfall approach can be applied if one is aware of the whole process It has some advantages It is very simple to implement The strategy is a linear model and well documented In this approach all the things are needed to document when each step is completed The biggest problem of this approach is that each step must be finished 100 before proceeding to the next one If one fails in one step then it is impossible to proceed and needed to redo the process Another disadvantage is that if clients require any changes it is harder to implement On the other hand the agile approach can be applied even if one is not aware of the whole process and does not have much experience in developing phase The work consists of small work cycles or modules It is an iterative p
58. ead as one long line This is very different from the python syntax where line breaks has the effect that semicolons have here Every executed part of the code is embraced in curly brackets makes the rest of the line anot executed comment And indenting is only for readability this means that Java Scripts can be minified If all unnecessary spaces line breaks and comments are removed the code will be shorter and work faster but will be impossible for people to read XML Extensible Markup Language XML is a markup language that allows users to define their own tags and attributes XML is platform independent as it is a plain text file Besides XML is self descriptive where people can easily read and understand its tags and attributes XML is well structured so it can be processed automatically XML is a 29 kind of umbrella language for all kinds of elements like GML The new versions of HTML use XML XML serves different purposes from displaying geographical information to solving mathematical formulas Because of these advantages XML is the most commonly used data exchange format on the Web On the other hand as it uses tags to delimit data it is bulky sometimes On the other hand parsing XML is not effident especially in languages such as JavaScript the most commonly used scripting language on the Web Fu and Sun 2011 See next section for an example of XML JavaScript Object Notation JSON JSON is a lightweight computer data
59. earching information in these Likewise a spatial index can be created on the geometry of a spatial database This can help to speed up spatial queries and visual displaying of spatial data 19 Normalization The design of a database may not always be straight forward Normalization is a way of making sure datain a relational database is arranged with the least possible amount of redundancy and making sure change is easily manageable Balstr m Jacobi and Bodum 2006 151 Normalization is a stepwise approach of rearranging data first achieving 1 normal form through 3 5 or even 6 normal form depending on the source According to Balstr m Jacobi and Bodum 2006 s 151 normalization is not an objective science and databases are often seen as being normalized when 3 normal form is achieved On the other hand lots of sources describing the importance of higher degrees of normalization could be found The greater the size of a database the more important normalization is Balstr m Jacobi and Bodum 2006 151 Normalization of only the first three normal forms will be discussed 1st normal form For a database design to achieve first normal form the database must have a unique and unambiguous primary key so that each entry can be uniquely identified foreach record There must also not be repeated groups Balstr m Jacobi and Bodum 2006 151 152 which means that a column of properties cannot contain two or more properties for one en
60. el In the example the internet intermediates the connection between the clients and the server Fu and Sun 2011 The internetis not necessarily always the connection between servers and dients It can be on a local network between computers as the clients and a printer as the server Server Clients Figure 6 The relation between clients and servers In web application more servers can be used to fulfil the requirements of the server A basic workflow of a web application is as follows Fu and Sun 2011 22 The web server A user initiates a receives the request The user receives request Typically and returns a result the response through a browser through the through its client internet etc Figure 7 Workflow of a web application On the server side programming languages as Java PHP Python or VB etc is doing the work They are responsible for accepting requests from the clients and serving clients with responses The most popular client type is the Web browser dient Among other types of clients FTP IMAP and SOAP clients can be mentioned Fu and Sun 2011 The web browser client is a software application for retrieving and presenting information resources from a server on the Web The web browser is called the face of the Web On the technical side the browser has implemented HTML specifications so it knows how to communicate with the Web servers While Web browsers differ regarding implemented software dif
61. em the environment and support they need and trust them to get the job done e The most effident and effective method of conveying information to and within a development team is face to face conversation e Working software is the primary measure of progress e Agile processes promote sustainable development The sponsors developers and users should be able to maintain a constant pace indefinitely e Continuous attention to technical excellence and good design enhances agility e Simplicity the art of maximizing the amount of work not done is essential e The best architectures requirements and designs emerge from self organizing teams e At regular intervals the team reflects on how to become more effective then tunes and adjusts its behaviour accordingly Agile Manifesto 2012 15 Complete ae esting i u WN Y Figure 4 Development Methodology of Agile Approach Development If any project has very little planning in the beginning Agile approach can be a good method to choose for the project As it is mentioned earlier Agile is an iterative process so there is plenty of opportunity for changes The basic idea is that working with codes by doing iterations it is possible to develop additional functionalities in the system The work cycles are short If the cycle does not work then one can follow another cycle as the process is not too long The main advantage of these methods is that if something
62. en client has open access to filtered data WebGIS is usually based on server side and client side strategies In a client server network arrangement the network services responds to the requests of clients The other components of WebGIS consist of GIS database server GIS server and the Application server Figure 11 The GIS database server supports a frequently access to data and the GIS server supports a large number of users database Internet Application lt wad Eat server Figure 11 The components of WebGIS Web server mainly sends ready made map images and applets JavaScript program It also passes requests to CGI programs for further processing The application server manages connection between web server and map server It also interprets requests and passes it to the map server Application server handles transaction and security Map server as a major component of Internet GIS performs spatial queries analyses generates and delivers maps to the client A web mapping server uses different protocols from HTTP like Web map service WMS web feature service WFS and many others protocols to respond the client The protocols are designed specifically for the transfer of geographic information whether it is raw feature data geographic attributes or map images See Figure 12 A common web based GIS System with Getcapabilities server for examples of this Peng and Tsou 2003 Tier 1 Tier 2 Tier 3 e Figure 12 A
63. est different approaches to improve the performance An approach could be to compare the performance from data that was imported to the database system as a shape file compared with a database table Other configuration settings could be tested to improve the performance As background map we chose to use an API Google maps is as earlier described the API within map APIs Primarily due to the tremendous support available on the intemet But the Google Maps API suffers from lack of possibilities to edit map styles OpenLayers is known for its flexible behaviour due to controls and styling etc It is easy to implement and is by far the most popular open source map API OSGeo 2012 We discovered that the popularity of an API helped supporting implementation through forums and blogs For that reason it is seen as a reliable map API to us We chose from the beginning of the project that we should try to stick to open source software to be able to add and manage as many functions in the system as possible This way we will be able to modify the system to meet the demands from the users One could argue that this approach seems like the waterfall to choose something from the beginning and use it as a guideline the rest of the project But on the other hand this choice gives the opportunity to modify the system according to the agile approach 5 3 Application This project was carried out as a web application While this may not seem as a subject to discussio
64. evandet for at undg iltsvind York j3 Hvis der er kv lstof i fjord eller s Leeds Kingston upon Hull pue Olsztyn fremmer det vaeksten af alger ig Schwerin Iitsvind del gger dyre og A Szczecin EPSG 4326 coordinates 9 86920 56 72420 planteliv statior earch for municipal Figure 27 The overview design Map panel The map panel contains of course the map which has the OpenStreetMap as a background map zoomed to the full extent of Denmark The map controls are displayed in the left part of the map and they control moving around and zooming In the right bottom corner of the map there is the pointer coordinates that are real time updated And in the bottom left the scale bar is placed The data is represented on Denmark s territory by small circles with three different colours See Figure 28 65 ae Me ir Manera Han UA Naron i She Figure 28 The map panel Bottom panel View Stations VIEW STATION fid name adress postal_cod contact_na phone1 phone2 email m_name total_n datec1 total_p datec2 ph datec3 Apr 11 Apr 11 Apr 11 y _ Grumvej Ulrik 2021 Hedensted 2012 2012 2012 ViewStation 186 Juelsminde 48 8721 a 76749280 7569 uf hspv dk Komo 55 0 7 00 00 6 0 7 00 00 8 0 7 00 00 AM AM AM AAA Figure 29 The bottom panel When a facility is selected the information about name contact address and all latest measurements are displayed in this panel Bottom bar The bottom bar has two search boxes that allow the u
65. ew it can be used to limit the amount of legal inputs and thereby preventing unwanted use of and access to the database GeoServer 2012 Regex syntax is not straight forward and as is stated in the GeoServer handbook Regular expressions are a complex topic that cannot be fully addressed here GeoServer 2012 This also holds true here The default regular expression is set to A w d s which will accept w Alphanumeric characters plus Xd digits and s white space characters But not characters like Danish letters like ze a A A and If special characters need to be accepted this has to be taken into account Adding single can be done by adding Y to the expression e g A w d s Other examples can be A d eE which only accepts floating point values which the default does not because floating point can include the character And A Accepts everything except and which characters such as prevents most hacking attacks GeoServer 2012 OpenLayers OpenLayers is a dient side JavaScript framework which makes it possible to put a dynamic map in most modern web browsers Since it is a purely client side application it is independent of any server It is capable of supporting various mapping APIs such as Google Yahoo OGC WMS OGC WFS KaMap Text layers to name just a few One big advantage of OpenLayers as compared to its commercial counterpar
66. f course vital to understand the user s ability to learn about these abstractions The graphical variables can consist of points lines polygons pictograms text etc These can vary in size darkness shape colour orientation texture etc In general will no visualization ever be perfect but with a little consideration the level of satisfaction a person gets using a product will increase Fu and Sun 2011 Representation of geographic data The spatial information is distinguished by other kind of information through an important element the geographic location Representing data in GIS systems is related to representation of geographical location The biggest benefit of GIS is the location because different kind of information can be visualized in the same geographic location In GIS if there is more information that has the same location it is fundamentally to have the layers that the data is represented on aligned If the layers are not aligned then a common spatial reference system must be chosen Longley 2004 The spatial reference system is defined by projection coordinate system and datum The features usually have their location represented on the surface of earth based on geographic coordinates while most GIS data is visualized on a plane map In this case the map features are based on x and y Figure 16 Measurements of geographic coordinates while the objects have geographic coordinate coordinates Kunen 2008 system whi
67. fall model Buzzle 2012 The goal of the model is to fulfil every step 100 unless one cannot proceed to the next step The steps in the model are described below 13 Requirement gathering and analysis The first phase of waterfall model is the requirement phase which indudes meeting with the clients to understand their requirements The most crucial part of the system is to understand the requirements of the clients carefully as misunderstandings may raise validation errors The team should be very careful with the requirements so that in the endit can fulfil all the requirements System Design The requirements of the dients are studied very carefully and these are broken down into several sections or modules Then the hardware and software requirement are identified to follow the steps Interrelation between the modules and the algorithms diagrams etc all programming and implementation are identified in this step System Implementation Actual coding is taking place in this step In the system design phase all the algorithms are designed and here a software program is written based upon them and the codes written for every module are checked System Testing In this stage the implemented software modules are tested and if there exists any bugs or errors these are correctedin this step After the code is rewritten it is tested again until the desired outputis achieved System Deployment and Maintenance The final phase of the waterfall
68. ferences in performance and compatibility may happen Thick client Client side processing of data Clients interact with the data and other GIS services through the internet Thick client architecture relies mostly on the client beyond servers to perform any functions accomplishing by a web browser or a native client application Here the dient performs most functions Client side applications allow the thick client to request the source data from the server When the server processes requests and sends information the client renders maps and performs analysis In this architecture the server does not perform all the tasks It sends downloadable GIS capabilities and data is processedin the user s computer An example illustrated in Figure 8 Example of a client side strategy Client side architecture follows some steps First they send a request to the server Then the server processes the request and returns information and data Then data is processed on the user s computer Due to several advantages client side strategies are good Clients can interact very fast with the server Data resides and processes locally The users posses the controlling power of data handling When users send requests to the server and get the response they can work with the data immediately Againit minimizes pressure on the server as only few tasks are performed there Fu and Sun 2011 But client side strategies have some disadvantages also This strategy is sometimes
69. gy is shown in Figure 21 Related to the theory we know that a map should not contain more information than necessary for the purpose of the map Later in the report we will make a perspective on how this can be improved y 1 i Figure 21 Local symbology visually interferes with the point of discharge Our data is presented through a web map service The choices for styling in this web map service follow the model presented by Brodersen 2008 figure 15 52 The value is that the producer wants to make data more accessible The way to do this is through the apparatus called a WebGIS solution The content is the data from the WinSpv database and the interaction is how we manage to express the information We do this through the styling of the WMS as explained earlier but how should data be represented visually Points will be used to represent each facility and each point of discharge Since we are showing facilities that have an exceeded compound value due to the limit at the points of discharge only points of discharge will be shown in the first place Each point will have a red yellow or green colour depending of the degree of exceeding the limit value Green means that limit is not exceeded Yellow means that the limit is close to being exceeded and red means that the limit for the certain compound is exceeded It is defined in the styling that this will be shown in the range from 1 15 000 000 to 1 500 000 In the range of 1 500 000
70. h GIS involve a lot of coordinate transformation That means that a data registry about coordinates reference systems and transformations is required The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations accessible through a data registry This registry has geographic data coverage of the whole world but unfortunately it cannot cover all possible geodetic parameters used around the world The Geodetic Parameter Dataset is maintained by a subcommittee of International Association of Oil and Gas Producers OGP Registry 2013 45 The projections are defined in GeoServer in ESPG codes If the data that has to be published in the GeoServer do not have an equivalent projection in ESPG code then a custom ESPG code can be created The data used in this project has a well defined ESPG code so it is irrelevant to discuss how to create a custom code 46 3 Methodology In this part the process used for achieving the desired objectives is described First there is the description of the system design documented and argued Further on is the implementation chapter where the system is detailed and the reasons why there were chosen specific procedures are presented The chapter ends with data description and preparation where datais describedin details and the preparation are argued 3 1 System design The system design is the conceptual implementation of the project Based on the t
71. has open access to filtered data This semester we decided to conduct a project on webGIS application The purpose of the work is to create a webGIS solution for wastewater with the possibility to search from different perspectives such as geographical searches and searches on spedfic measured parameters Therefore we chose wastewater data in Denmark The data is an extract from the database called WinSpv containing data about wastewater from Danish wastewater facilities The data is used for various tasks regarding wastewater governance WM data 2006 WinSpv is an older database and it is required that each wastewater facility report analysis on a number of compounds a number of times every year Compound is a word that will be used throughout the report It is used as a common word for chemical substances measured in wastewater All data is collected in a database The age of the database is for instance visible in the municipality codes which still follow the old municipality numbers Our extract contains data from January 2012 until November 2012 Each time a sample is made on a facility measuring one compound there is one row We have more than 58 600 samples rows spread on 721 wastewater facilities all over Denmark exduding Bornholm Data in WinSpv is divided in an administrative part and a data part The local municipality is responsible for keeping the administrative part updated The administrative part includes information about the f
72. hat is returned This particular function will concatenate a string with the elements from the list a with the string call and some other strings and then return the result string to where the function was called The first line within the function is where a local variable t is defined t can only be used inside this function and is not defined in the rest of the script The for loop is iterated over the number of elements in the list a The loop will add call the iterated element of a and or to the string for every iteration Then the next line will remove the last 4 characters of the string And finally the string is retumed to where ever the function is called If the following code is used strvar syntaxer a b c type Then the variable strvar would contain the string type a or type b or type c And strvar could be used in the code Here the order of appearance is very important A function cannot be called before it is defined and the code is executed from top to bottom this means the function must be defined prior to the call and the use of the strvar must be subsequently 28 Usually you would want JavaScript for dynamic interaction between the website and the user and example could be checkboxes Checkboxes can be defined in a number of ways the following code will demonstrate how to use the result get the type checkboxes var ct2 formAdv getForm getVal Iz
73. he website will never be published and there are therefore no direct problems with the licensing The application development can be described as pseudo devel opment We are pretending to produce a product for a client which may or may not have commercial uses for the application More liberal alternatives do exist But they would not as easily communicate with GeoExt which communicates well with OpenLayers 5 4 Agile vs waterfall Among most of the renowned strategies Agile and waterfall approaches are used mostly by the software developers Waterfall strategy is applied when people are aware of every step they follow The biggest problem of this approach is that each step must be finished 100 before proceeding to the next one If one fails in one step then it is impossible to proceed and needed to redo the process Another disadvantage is that if clients require any changes it is harder to implement On the other hand Agile approach can be applied even if one is not aware of the whole process and does not have much experience in developing phase The work consists of small work cycles or modules Itis an iterative process So it is possible to get a more suitable output for satisfying the product by following some cycles We decided to follow agile approach for the project as we are working on the project was dealing with this kind of problem statement for the first time The reason behind is that there was no knowledge about the whole pro
74. hen the name from the list is selected is the part where differs Stations ithin limit Value close to limit Limit exceeded Select compound for overview M Zoom to Denmark Show wastewater treatment facilities and pipes Show municipal borders Det samlede indhold af kv lstof i spildevandet Det skal fjernes fra spildevandet for at undg iltsvind Hvis der er kv lstof i fjord eller s fremmer det v ksten af alger Titsvind del gger dyre og planteliv from the other tool because the map is zooming to the selected Figure 32 The simple search municipality Figure 34 A search result from a spatial search in the bottom bar Right panel The right panel is divided in two search options simple and advanced These are described separately but they are linked in terms of usability 68 Simple search The simple search panel contains the legend panel that include the types of markers from the map with their description Under the legend panel there is a drop down button Select compound for overview which contains a list with the compounds See Figure 32 If a compound is selected then the map is showing the markers according to the selection In Figure 35 for example the pH is selected so the colours on the map are displayed according only to pH values and the relationship to the according limit values ECAC Stations m Within limit Value close to limit m Limit exceeded ventspils
75. ically in tree structures The rules are that every node in the tree can have several children but only one parent and that only one to one or one to many relations downwards in the tree are allowed Balstr m Jacobi and Bodum 2006 144 This way of ordering data is well known from way files are saved in folders and searched in for example windows browser A folder can have a number of subfolders which can have a number of files but a file cannot be in two folders at the same time without being actually copied and thereby having redundancy Network Database Management System NDBMS The network DBMS has a lot of similarities with the HDBMS The difference is that here children can have more than one parent so it opens up for many to many relationships Balstr m Jacobi and Bodum 2006 144 With this feature some redundancy can be eliminated by not forcing the same information in more branches but instead the information having several parents 18 Object Oriented Database Management System ODBMS The object oriented DBMS is both newer and more immature than the other three mentioned DBMS types Anfindsen 1993 42 It follows the structure of the object oriented programming and includes classes subclasses and objects with inherited properties According to Balstr m Jacobi and Bodum 2006 s 156 the ODBMS has great unutilized potential and they are well suited for some spatial data because a lot of spatial information and metadata
76. icipal borders layer can be set in order to make it appear less distracting Figure 39 Figure 39 An example of opacity differences A little further down there is a description box that contains data about compounds See the bottom right of Figure 40 Advanced search The advanced search panel it is a little different from the simple search see Figure 40 Here there is an update button and any change that is made in the panel has to be updated in order to have an effect on the map In the top of the panel are inputs for custom limits with two boxes for maximum and minimum limit There is also a text where the selected compound and ts maximum limit are written The default value is the Total N which is the total appearance of chemical compounds containing Nitrogen N I Under limits in the advanced search panel there is the tool select displayed plants by type with 4 checkboxes cleaning facility separate surface water industrial water and other These types can be selected one or many at the time butin order to take effect the update button has to be used The select ownership types is the next tool built in the panel that has three 70 Simple Advanced Currently selected compound is Total N unit mg l National limit 8 mg l Select displayed plants by type 4 Cleaning facility Y Separat surface water Y Industrial wastewater Y Other Select ownership types Y Private V Municipal
77. igin which returns aresult inside the application A commonly known API within WebGIS is the Google Maps API The Google Maps API is a free API and widely supported in tutorials forums etc This is by Gosnell 2005 called the main issue to make a popular API the availability of support OpenLayers is an API as well It differs from the Google API due by having an open source approach 2 4 Programming The following subsection describes the different programming languages used The languages are introduced and their advantages and disadvantages are discussed Other than that their basics are described this includes the terminology the syntax and some examples with relation to their use in the project are described and commented HTML Hypertext Markup Language Hypertext Markup Language which is the main language for creating web pages developed by scientist Tim Berners Lee in 1990 HTMLis the hidden code that helps us communicate with others on the World Wide Web WWW It contains contents a layout and format The web browser interprets the HTML code and displays the webpage in the web designer s point of view Tags e g head body table center and fonts are added in the text while writing HTML These tags tell the browser how to display text or graphics in the document Web pages with pure HTML have a plain user interface HTML allows images scripts like JavaScript and objects like browser plug ins to be embedded to enhance the user
78. ined features of each municipality and the facilities of each municipality and Municipal border then these two were merged and dissolved in one layer with 98 features named after each municipality A E D Figure 23 Minimum bounding geometry for municipality borders and points of discharge Figure 24 Result of minimum bounding geometry for Danish municipalities excluding Bornholm The shape setting used is called convex hull which makes a polygon like in Figure 23 In Figure 24 the whole analysis is displayed When a municipality is chosen in the GeocoderComboBox the convex hull shape will be zoomed to ensuring all munidpality features and points of discharge will be in the picture XY to line The wastewater reaches the wastewater facility and is cleaned From the fadlity the water continues through pipes to the point of discharge We have both the facilities and the points of discharge but we need to create our own fictional pipes to visualize that there is a connection between the facilities and the points of discharge so that the user knows which facility connects to which point of discharge This is done by the XY to line tool in ArcMap We simply use the two corresponding points to create a straight line that will represent the pipe 3 3 Data How data is structured is a deciding factor for how the work process comes along and in this chapter the relationship between the data and the project will be described The cha
79. ingful colouring a relational value would be preferable For example if we have a pH of 8 9 and the limit is 8 then we would from the above get 0 9 and as a comparison the value for calculating lead in water resulting in 0 9 means that the value is just inside the legal range So these two numbers cannot be evaluated in the same way because one is relational and one is not We ended up favouring the many compounds over pH byimplementing the following calculation Abs 1 CASEWHEN mal mal2 c lt c mi1l mil2 THEN Smal mal2 c mal mal2 ELSE c mil mil2 c END AS result Where mal mal2 are maximum limits mil mil2 are minimum limits and c is the value result is the value used for visualization The above first examines whether to look at the maximum limit or the minimum limit by doing the comparison max minlimit value value maxlimit Then this value is divided the maximum limit or the measured value depending on which limit is examined If a non pH value is examined the minimum value of 10000 is parsed which potentially makes the calculation vulnerable to very high values The reason that both mal andma12is used is due to regex complication this is explained in 2 5 Regular expressions Like explained in the implementation the limit values can either be user assigned floating point values or default values taken from the table Floating point values and table values c
80. inx FLOAT arcpy AddField management tableName iny FLOAT arcpy AddField management tableName outx FLOAT d n eNa d When the fields for the two tables are created we insert a curser in each table We start reading the data file in a for loop for each line like described earlier in Common language examples un There are some lat lon values which contain a instead of In order for them to be floating point values this must be corrected This is done by using the module re which has substitution functionality if in aList 10 aList 10 J re sub aList 10 We start writing to each field and define which attributes from the old table goes to which attributes in the new tables Converting from CSV to DBF In the previous section we showed how to split a csv file At the same time we convert it into a database format that can be handled within databases The conversion is done by using the arcpy CreateTable_management This creates a new table in a spedfic workspace We use a spedfic script to convert a couple of tables that are within the csv format The script can of course be modified to delete or replace certain records etc Database processing This section will explain the database querying done in order to get the relevant data out of the database structured as illustrated in figure 25 The querying is divided in two parts e Creating a suitab
81. is inherited Basic elements of a database In this subsection basic elements in databases and relational databases in particular are described This is done in order to lay the ground for the use of the terminology later on Tables Tables can be described as the data containers of relational databases They have a number of fields and a number of entries usually represented in a matrix like figure 5 Fields examples 1 Tom 25 Entries 2 John 4 Ann 96 Figure 5 Example table In the example in figure 5 there are three entries corresponding to three people with matching information meaning Tomis 25 years old and has ID 1 There are three types ofinformation about these people called fields A database can contain several related tables Views A view is a dynamic representation of data a window of the data so to speak Date 2004 73 While a view will look like a table they differ from tables by not being stored as data but rather as queries on one or more tables ibid Because views are dynamic and light in data storage they can be used for splitting up advanced or extensive queries Indices An index is a data structuring that is used to speed up searching in data on a table Balstr m Jacobi and Bodum 2006 138 Indices are not visual to the user and in that way they can be seen as maps of the data for the computer to find its way through the data Indices are created on one or more columns in order to speed up s
82. is less work for the users to perform The user needs only a Web browser to perform the task Any other software is not needed here to install from the user side Most of the tasks are processed in the server so the client does not need to have a powerful computer On the other hand it has some bottlenecks also The servers always stay in pressure due to the lots of requests Interaction with the user is very limited as the interface is build with HTML and JavaScript which is not compelling with the user interaction Fu and Sun 2011 Processes request ae sends information Si _ gt J f LS CGI Script Client Po sil ien displays Response Server Output returned y 5 send to information to server client Figure 9 Example of server side strategy Foote og Kirvan 2012 24 The division of the tasks between thin and thick client Due to the advancement of technology both the server side and client side strategies are becoming more and more powerful and can take greater workloads Figure 10 Distribution of tasks of the very thin and thick layer and how it can be best practiced shows different task divisions between the server and the client in a best possible way In the very thin client architecture most of the GIS activities are performed by the server while the opposite scenario is seen in case of very thick client architecture The best practice recommends that base maps query and analysis are done by the server while dient ma
83. l zoom the map to the extent of all of Denmark e UpdateView This function contains some of the main functionality of the JavaScript It is run every time the data from the database should be re fetched according to the userinputs The most important part of the code is the layer method layer mergeNewParams This makes a request to the GeoServer WMS with new parameter input for the parametric view When data is retrieved from GeoServer the layer and the legend are redrawn When defined these four functions can be used in the rest of the code The syntaxer functions are actuall y used in order to call the UpdateView with SQL syntax for the new parameters Functionality The functionality is implemented object wise This means that all the visual elements are coded separately and then put together The whole page is filled by a viewport A viewport is a container element from Ext that can contain other elements namely the map and panel so that they will resize to match the page document The viewport is defined in the last part of the script This is because the elements that is inside the viewport must be defined before the viewport in order for the execution of the code to work elements must be defined before mentioned in the code Inside the viewport the following structure applies Viewport e The map map element o Background map o Overlay Layers Points of discharge Facilities Pipes Municipality Selection layer
84. ld be a thick client system which provides with unlimited opportunities from client side Peng and Tsou 2003 WMS specifications The WMS specification covers primarily the picture class where only pictures of maps are shown to the web client while all other tasks induding data selection map rendering are conducted in the server Map servers should be able to answer the user s request Especially three functions are needed to consider First the map server should be able to provide users with maps in their browser secondly provide information required by the client for example information on specific areas and specific layers And finally the map server should be able to provide information on map interfaces and map layers that it can serve These three functions are supported by three WMS interfaces map feature and capabilities interface which are also known as GetMap GetFeaturelnfo and GetCapabilities Peng and Tsou 2003 GetMap Map request interfaces mainly focuses on the display and production of web based map services in the form of gif png tiff The URI parameters provides the information regarding the coordinate system of the map area information to be shown output size format rendering style and other parameters like map layers picture format picture format background colour etc Table 1 shows the parameters used in the map request interfaces Peng and Tsou 2003 34 URL Component http server_address path script W
85. le table with all the relevant data lined up in a way so data can be accessed easily from this one table See appendix 8 3 Creating a table from the databases e Creating a flexible view from the table allowing parameters to control the visual output of the table See appendix 8 3 Parametric view 60 A suitable table Because of the implementation structure we have chosen one layer in the final webGIS application is one database view For this reason we need to assemble all the relevant data from our four databases in one table See ER diagram figure 16 in 3 1 Database structure design The elements required to be in this table are e Facility data Thisis the address contact information facility name ownership munidpality etc e Measurement data We need two columns for each compound one with the measured value and one with the corresponding time e Limit data Data showing the limit specific to the fadlity and the compound e Historical data In order to show historical data each historical iteration of the table must be added to the total table so that each facility is represented the amount of historical records plus the most recent data Facility data Limit data Measurement data Name adaress sz les ies All facilities AA ee ee ee _ 1 june 00 00 for one time gt iteration n 1 june00 0
86. llipsoid There are various coordinating systems and most of the countries have created their own for an easier measuring inside their borders Some examples of coordinating systems are WGS84 World Geodetic System NAD83 GRS80 etc Longley 2004 Projected coordinate systems The projected coordinating systems are map projections of converted geographic coordinates to plane coordinates This is done using mathematical expressions The projected coordinating systems have a constant area of length and angle across 2 dimensions contrast to the geographic coordinate system The most common map projections are Transverse Mercator Equidistant Conic Albers Equal Area Conic and Lambert Conformal Conic The most used systems are The Universal Transverse Mercator UTM Grid System the State Plane Coordinate System SPC and The Universal Polar Stereographic UPS Grid System A very important aspect is that changing the coordinates for a location is related to the datum and ellipsoid under which the coordinates were based Longley 2004 W Paul 2004 It is a must to realize and understand for GIS applications that each UTM zone has a different projection and system of coordinates When a bigger area is shown and maps from different UTM zones are merged into a single map some distortions may occur This problem can be overcome by using a different coordinating system and re projecting the data Longley 2004 EPSG Geodetic Parameter Dataset Workings wit
87. lowing main operations Get capabilities Requests service metadata The response is an XML that describes service content and capabilities including the feature types it can serve and the operations it supports DescribeFeatureType Requests the structure of the feature type that WFS supports GetFeature retrieves a geographic feature and its attributes to match a filter query LockFeature Requests the server to lock on one or more features for the duration of a transaction Transaction Requests the server to create update and delete geographic features Fu and Sun 2011 72 Based on these operations two main classes of WFS can be defined namely basic WFS and transactional WFS WFS T Basic WFS is considered a read only WFS It implements GetCapabilities Describe Feature Type and GetFeature while WFS T implements all the capabilities of basic WFS with the transaction operation This also implements the Lock Feature operation WFS T is considered as a read write WFS WES can be used for mapping and query It is also used for geographic data clipping projection zipping and shipping Fu and Sun 2011 GeoServer 2 1 3 GeoServer is an open source software server written in JavaScript language which allows users to view edit and share geospatial data by following Open Geospatial Consortium OGC It shares data from any major spatial data sources for example from files on the local disk to databases as it is designed for interoperabilit
88. model is the maintenance phase in which the completed software product is handed over to the client after testing When the software product is handed to the client it is the responsibility of the software development team to take maintenance responsibility by visiting the client site If a customer wants any changes then the system has to follow the steps from the beginning which is the biggest shortcoming of the system Waterfall model is easy to implement It depends on different phases thus this interdependency may lead to development issues In spite of the shortcomings waterfall model is accepted all over the world Buzzle 2012 Pros and Cons The Waterfall method Pros The linearity makes it simple and low cost to implement Agreat advantage is that every stage is easy to document this makes the designing phase easier to understand Cons There is no tuming back if something in the requirement or design step went wrong It can be complicated to smooth outin the implementation step Ifthe client you work for comes up with additional requirements to the software it can cause a lot of confusion Additionally the environment can change also leading to new requirements Changes made later in the completed software can resultin a lot of problems The biggest drawback is that there is no working system until the final stage of the development is over So it is not possible for the client to make comment in the process or even
89. mune 64 4 Result In this chapter the functionality and design of the web application are presented The chapter starts with the functionality of the product where every service is described argued and accompanied with an example The design is related mostly to cartography part described in theory so here the layout scheme is presented and argued The shortcomings are the services that were not finished but they could have been if the time would not have been an issue 4 1 Functionality The functionality of the project is infact represented by what the web application can do The application is formed by its services that work together as a whole The functionality description starts with an overview of the website and is followed by the each service separately Overview design The start page of the application shows on a map the latest measurements problematic or not see Figure 27 It also has the functionalities built in the map panel bottom panel bottom bar and right panel which are described further on tec Simple Advanced ig ma Stations m Within limit Jonkeping Value close to limit m Limit exceeded Gireg Bors Select compound for overview Vaio 5 Kalrrar ra Zoom to Denmark Show wastewater treatment facilities and pipes E Show municipal borders Opacity Kannn nrpan Gdynia A Det samlede indhold af kveelstof i e Gdansk spildevandet Det skal fjernes fra y Koszalin Elblag spild
90. n alternatives do exist and it is sound to examine why the web application was chosen Most notably the project could have been carried out as a non cloud based software It could have resulted in a program installable on computers or smart phones or other devices Even though there might be a general discourse of IT moving towards more cloud and browser based solutions a lot of GIS software is still being developed for offline and or separate software use This might be closely related to the discussion of thin vs Thick client where thin client applications are mostly limited by the bandwidth and the server speed thick client applications are more limited by the client side performance which might be sped up by having separate software and data stored locally We will discuss the thin and thick client again later An important argument towards web application over separate software is access A web application runs on common software such as java that many users will have before they encounter the web application 75 therefore the application will be immediately available and accessible to them whereas the separate software will have to be downloaded and installed So the type of software must be chosen to comply with the requirements of the users and maybe also how to reach the most users As described the application have three distinct target user groups the professionals the NGOs and the general public For the first and maybe the se
91. nd custom limits selection based on facility types and ownership and historic data that could be applied in the map We created a web application following the user requirements We presented interactive data to prevent distraction and over representation of data The cartography and the instruments are self explanatory Our second research question was How can data be gathered refined and stored to fit into the application functions It explains how data went from being a raw WinSpv data sheet to being fully functional updatable spatial databases To answer our second research question we followed some steps First we analyzed how data is looking and how it could be used We removed bad and unused records and data to improve performance and clarity of data Then data is refined for better usage by converting commas to periods and adding Ids Data was stored in a relational database where data was normalized Then queries are designed in order to align data in a table suited for interaction between GeoServer and OpenLayers A script is created that creates new fields in the measurement table and runs the queries in order to have the new data in the final table Our third research question was Which platform should be used in the application To answer this research question we used python programming PostGreSQL GeoExt etc instead of other platforms In the discussion chapter we justified why we used these platforms The whole project followed s
92. nd runs the queries in order to have the new data in the final table Answering research question 3 Our main intention was to prepare a WebGIS application with searching fadlities for wastewater treatment and their measurements For this we used different platforms in our application We used python PostGreSQL OpenLayers and GeoExt for the execution of the application e Python programming A spatial database was created from the primary data which was in xls format by using python programming e PostGreSQL Spatial database is handled on the PostGreSQL that is directly linked with GeoServer e OpenLayers and GeoExt We used JavaScript and html document to run the application with advanced search applicability 78 6 Conclusion The purpose of the project was to create a webGIS solution for wastewater measurements with the possibility to search from different perspectives such as geographical searches and searches on specific measured parameters For this purpose we chose data in Denmark Our problem statement was How can an open source WebGIS application are designed in order to interactively display and make searchable wastewater facilities and their measurements To solve the problem we identified three research questions Our first research question was What types of functions could be developed to support the use of the data in the application To answer this research question we identified some functionality for example choose compou
93. ng and graphics in the loaded links in the top e GeoExt js is a further extension of the possible functionality This enables the use of a legend panel map panel feature reader and more e js is also an extension of the JavaScript functionality This enables the use of the map the layers the communication with GeoServer Other than this the title and the character set are assigned JavaScript implementation In the following section the implementation of the web application using JavaScript will be discussed The overall structure will be outlined and parts of the code will be explained 53 The JavaScript used in the HTML document can be viewed in full length in Appendix 8 1 HTML and JavaScript It consists of two main parts e Initialization definition and assignment of global variables and functions e functionality here everything to do with the actual map and layers functionality is executed Initialization In the first part of the JavaScript global variables are defined and assigned default values This is done in order for them to be dynamic part of code later on Their values will change according to the user input and will be put to use in functions and methods In the initialization four functions are defined e syntaxer a call and syntaxer2 a call These are used for making chosen elements appear in SQL compatible syntax the code is also explained in 2 4 JavaScript e startpos A function that wil
94. no BBOX size it will zoom as close as the background map allows This is not desired as it is simply too close The other GeocoderComboBox used to zoom to the municipalities had another problem While the bounding boxes worked as they should the problem is that the shape layer of the 98 Danish municipalities contained 1777 features of which one could be zoomed to at a time This was due to the fact that islands are separate shapes even though they are part of the same municipality Another issue was that some of the facilities points of discharge was located in the ocean outside Figure 22 Example of a buffer around the facility 55 the municipality boundaries and if a municipality was zoomed to the zoom might now show all the important features To respond to the first issue 3 km buffer zones around each point of discharge were created The buffer size of 3 km was chosen to ensure that when zooming to a facility both the facility the point of discharge and the immediate surroundings could be seen Using the GeocoderCombo Box with the buffer zone layer instead of the point features will zoom to the periphery and use these as bounding box See figure 22 The buffer analysis was done using the Buffer analysis tool in ArcMap This requires shape file as input and the chosen buffer size The other issue took a little more work to get around ArcMap has a tool called Minimum Bounding Geometry this was applied to both the comb
95. ome steps The first step of the project was to make a spatial database from WinSpv excel data by using python programming The spatial database is mediated on the PostGreSQL program that is linked to the GeoServer on two directions The first link is directly to the GeoServer because it is using the data from the Spatial Database through PostGreSQL the server requests to SQL program on parameters used on the website through the parametric view is the second These processes are done automatically when the webpage is accessed Finally using JavaScript all the parts are put together in the html document and run as a website through the GeoServer and with the service from OpenStreet Map We decided to follow the agile approach for the project as we are dealing with this kind of problem statement for the first time The reason behind is that there was no knowledge about the whole process to follow We do not have experience to fulfil the demands of waterfall methods But we dedded to follow the documentation of the programming and development from waterfall method as the documentation is necessary for the project In the beginning of the project we identified some of the functionality for the system and we managed to accomplish most of them that satisfied us in spite of having lack of programming language and time limitations In spite of this we hope that our project will help anyone for further research 79 7 Perspectives Throughout the discussion and
96. onprofit organization OpenStreetMap 2013 The OpenStreetMap Foundation has some objectives e To make OSM data available for anyone for editing and in whole 51 e The data being current e The data to approach geographic truth or ground truth e That human add and curate data e That the data and responsibility for it belong to all contributors e To facilitate decision making in the community where necessary e To be the ultimate court of conflict resolution OpenStreetMap 2013 Anyone can download and use map data from OpenStreetMap But geodata is controlled by a license The most positive thing is that it is free to use that means people do not need to pay to use geodata There is no copyright license usage and other kinds of fees Anyone can use data for any purposes like personal community educational commercial government or any other uses OpenStreetMap 2013 Cartography The user interface is designed with simplidty and intuitiveness in mind All tools and controls are aimed to be self explaining in order to maximize convenience of use The graphical interface regarding the map and the representation of data is designed to be as simple as possible at the first look One thing that can really disturb a map is its background map We ended up using OpenStreetMap despite of disturbing symbology The disturbance consisted of a too detailed symbology relative to the needs in the system An example of the symbolo
97. ools that were used the project has the following diagram that is described and shown in Figure 17 Municipality layer Parametric OSM Background map PostgreSQL PostGIS Spatial Database WinSPV data update data Figure 17 System design of the project The main idea of the project is to display and work with the geo referenced data on a map through the web in this case represented on a website In order to do this a spatial database had to be created from the initial data WinSpv data received in an excel document using python programming The input data for the spatial database has three entries because besides the starting data the WinSpv there has been designed an upload data python script that converts the data into executable SQL commands and sends them to the database and one more entrance is the over layer Municipality is uploaded manually The Spatial Database is mediated on the PostGreSQL program that is linked to the GeoServer on two directions The first link is directly to the GeoServer because it is using the data from the Spatial Database through PostGreSQL the server requests to SQL program on parameters used on the website through the parametric view is the second These processes are done automatically when the webpage is accessed Finally using JavaScript all the parts are put together in the html document and run as a website through the GeoServer and with the service from
98. ould be importedin pgAdmin Afterwards the GeoServer was set up and the html webpage application was developed Finally the system was tested In the second iteration the system was developed More GeoEXT components were added The database limits were set through the parametric view and a compound update script was done The update button was set This is important because all the components from the advanced search are taking effect because of it The third iteration was for improvements If there is update button there should be something for the system to get back to the default values so a reset button was added New layers were added and using the Geocoder two new types of search was set up the municipalities and facility search Web Application Implementation In the following the implementation of the web application will be described The implementation of the web application in the following is divided in to three parts cartography describing the cartographical choices and implementation methodology HTML implementation describing the structuring of the HTML document and basic code elements and the JavaScript implementation describing the functionality of the web application OpenStreetMap OSM OpenStreetMap provides free geographic data like street maps and encourages the growth development and distribution of geospatial data for using and sharing by everyone It is supported by the OpenStreetMap Foundation an international n
99. owever we were unable to do this For unknown reasons the data was shown correct for all other projections than the Spherical Mercator but with slower drawing speed The drawing could be sped upif this problem was resolved 82 Bibliography Agile Manifesto Principles behind the Agile Manifesto from http agilemanifesto org prindples html Retrieved on 6 12 2012 2012 Agile Methodology Agile methodology from http agilemethodology org Retrieved on 5 12 2012 2012 Anfindsen Ole Jorgen Introduction to database systems Telektronikk 1993 37 43 Balstr m Thomas Database Technology slides Aalborg University Denmark 2012 Balstr m Thomas Ole Jacobi and Lars Bodum Bogen om GIS og geodata Forlaget GIS Geodata 2006 Brodersen Lars Geo communication and information design Aalborg Forlaget Tankegang A S 2008 BrodersenA Lars Kommunikation med kort K benhavn Nyt teknisk forlag 2008 Buzzle A Waterfall Model Phases from http www buzzle com artides waterfall model phases html Retrieved on 5 12 2012 2012 BuzzleB Waterfall model advantages and disadvantages from http www buzzle com articles waterfall model advantages and disadvantages html Retrieved on 5 12 2012 2012 Danish Environmental Protection Agency Bilag 4 til Dataansvarsaftale Appendix for accord 2011 Date C J An Introduction to Database Systems Pearson Education inc 2004 Foote Kenneth E and Anthony P Kirvan Web
100. patial Consortium Inc 2007 Open Geospatial Consortium Styled Layer Descriptor 2012 http www opengeospatial org standards sld accessed 1 3 2013 OpenGeospatialConsortium Open Geospatial Consortium retrieved on 04 01 2013 from http www opengeospatial org standards 2013 OpenLayers What is OpenLayers retrieved from 14 12 2012 from http docs openlayers org index html 2012 OpenStreetMap Open Street Map Foundation Retrieved on 4 01 2013 from http www osmfoundation org wiki Main_Page 2013 OSGeo OpenLayers Info Sheet 2012 http www osgeo org openlayers accessed 1 3 2013 OSM wiki Mercator wiki openstreetmap org 16 December 2012 http wiki openstreetmap org wiki Mercator accessed December 21 2012 Paul Woodward Map Projections and Coordinate Systems http maps unomaha edu Peterson gis notes MapProjCoord html accessed 01 06 2013 Peng Zhong ren and Ming hsiang Tsou Internet GIS Distributed Geographic Information Services for the Internet and Wireless Networks New Jersey John Wiley amp Sons 2003 PostGreSQL PostgeSQL about retrieved on 07 12 2012 www postgresal org 2012 Pumphrey Mike SLD Cook Book 2012 EPSG Registry EPSG Geodetic Parameter Registry 2013 http www epsg registry org accessed 01 06 2013 Sencha Licensing Sencha Ext JS Products Sencha sencha com 2012 http www sencha com products extjs license accessed December 23 2012 Swaroop
101. pt gt var map function init map new Map map element var wms layer map new Layer WMS WMS Layer Title http vmap0 tiles osgeo org wms vmap0 39 layers basic i map addLayers wms if map getCenter map setCenter new LonLat 10 55 6 lt faeript gt lt head gt lt bodyonload init gt lt divid map_element style width 500px height 500px gt lt div gt lt body gt lt html gt The first 1 7 lines are the basic html where the character set and the title is defined Here in line 6 it also defined the OpenLayers library And in line 9 a global variable is created There are two main sections in the code One is function init and other is map add layers These functions load all the code to set up OpenLayers map Creating a function that gets called when the page loads is a common practice The global map which was declared before is needed to make it into a map object from the map class Here the map class ID map element is defined In this section a layer object is also created from the WMS subclass of the Layer class In OpenLayers every map needs to have at least one layer The layer points to the back end or the server side map server Here layer s title and layer properties are also declared The source of WMS file is also shown here Thus wms_layeris created in this section Another thing in the code is that it needed to add wms_layer to
102. pter will focus on data handling as 56 scientific documentation for the purpose of being able to follow the thought processes going on behind the handling of the data We will describe how we process the data onits way to be published Preparation To make the data ready for publishing and improve performance some preparation is needed Data is by defaultin csv format Table 4 is showing how the first 7 rows of the original data look 57 KOMMUNE LOBENR ANLAEGSNAVN DS_KRAV_FRA UDLEDNINGSTYPE EJERFORHOLD KONTAKTPERSON 101 5 Lynetten 101 5 Lynetten 101 5 Lynetten 101 5 Lynetten 101 5 Lynetten 101 5 Lynetten 101 5 Lynetten 101 5 Lynetten TELEFON ADRESSE 32573232 Refshalevej 250 32573232 Refshalevej 250 32573232 Refshalevej 250 32573232 Refshalevej 250 32573232 Refshalevej 250 32573232 Refshalevej 250 32573232 Refshalevej 250 32573232 Refshalevej 250 POSTNR 1432 1432 1432 1432 1432 1432 1432 1432 FAXNR 32543122 NULL 32543122 NULL 32543122 NULL 32543122 NULL 32543122 NULL 32543122 NULL 32543122 NULL 32543122 NULL NNNNNNNN 6178210 6178210 6178210 6178210 6178210 6178210 6178210 6178210 2 Kim Rindel Carsten Thirsing 2 Kim Rindel Carsten Thirsing 2 Kim Rindel Carsten Thirsing 2 Kim Rindel Carsten Thirsing 2 Kim Rindel Carsten Thirsing 2 Kim Rindel Carsten Thirsing 2 Kim Rindel Carsten Thirsing 2 Kim Rindel Carsten Thirsing 727150 6178401 727150 6178401 727150 6173401 727150 6173
103. rocess So it is possible to get a more suitable output for satisfying the product by following some cycles The approach relies more on codes rather than documentation So there is avery little scope for documentation Another problem of the approach is that it leads higher expectations to get best possible solution We have decided to follow the agile approach as we are dealing this kind of problems for the first time The reason behind is that there was no knowledge about the whole process to follow Again we do not have experience with fulfilling the demands of waterfall methods But we have dedded to follow the documentation of the programming and development from waterfall method as the documentation is necessary for the project It was decided to follow agile approach considering all the pros and cons of the two methods as it gives opportunity to change when itis necessary If we are getting stuck in one step itis possible to start a new iteration that does not take much time The approach provides opportunity to divide the tasks among the members dynamically so no one had to wait while the others were working See Figure 20 50 Figure 20 Agile implementation process The method is also used because of the short time assigned to this project In this matter the whole project was developed in iterations In the first iteration a simple application with minimum functions was developed The database in xls was transformed in dbf soit c
104. rt an appendix is presented The appendix intended to substantiate the facts written in the report Each appendix is numbered and can be found in the contents of the appendix Content PROP ACO A costes concctvcceucdoveceeceny T sonsceecunssseoaceseses 5 RAGING AAVICC E T A A ei cals sdonuavsetacssssconssssees 6 Source METEKEMCO Siisera niaro ibs cau chews od ib dada 6 Character eterno Sii as i 6 Lists Of Abbreviations ertasini ido rated adn ie cd ies 6 No oy Loly ARPA DEI ENCON OO EEA E I E R OREN 7 CONTENU E E A E E EE E E ET 8 TL INtrOMUCTION PRE TTT T adanicnniaio tanos di cani0s 10 1 1 Problem Statement isisisi ana aai aea aa a E aa aaa 10 1 2 Report structure eienenn a oia 11 DTNCO Y AE EE T E A E E E EE E E 13 2 1 System design Strategiles cooooonnnccoconnnnnonononenonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnninnnnnaness 13 2 2 Database management system DBMS ooccccccccccnnccnoconnnnnonnnononcnnnnnnnnnnnnnnnnnnnnnnnnnnonnnnnnnnnnnnnnnnonanes 17 2 3 Web Archit CtUNG aia ana aeaaea oane ra aSa De Rana aaa Sangean RAAE EEE EEr ARAARA EREA 22 2 4 Progra MIMIN ca a ER E A E E a 26 2 5W b based GIS win sisissniesedeveesannssvavenedeveadsvieesaguealeas En aE n GEE SAE AEE AA REEE EO AERE ENERE EAER 32 2 6 CartO AE ONY LE E I E AE EAN 43 eA aolo Lollo A E T TT E A E E 47 L ES YStOM RSS E OENE E ENNE OSO REAN E 47 3 2 implementa ON arero ce 5850 Enie Seas bee AEE EEE EEEE TEE TSE EAEE AAE a ae 49 ERA
105. s Facility 1D Figure 18 First step in normalization of the databases The first step as depicted in Figure 18 achieved to get rid of all abundances related to facility data which initially were there for each measurement In order to get the needed information about the measured compounds and limits this data needed to be added to the database in order to not interfere with the normalization of the database therefore database describing compounds was related one to one with the compounds one compound measured in one measurement The limit values are specific to both the facilities and to the compounds Therefore a fourth database with a one to many relationship the facilities one facility has many limits and a one to many relationship to the compounds every compound has limits for each facility was added 48 Facility data Measurements Limits Measurement data Facility 1D Facility 1D Compound ID _ Limit data Compounds Compound data Figure19 ER diagram Facilities are uniquely identified by a Facility ID Measurements by a measurement ID and compounds by a Compound ID and limits by a combination of a Facility ID and a Compound ID User requirements To identify our users we have created 3 user types The types are made from thoughts on who might have interest to use our system based on information from Danmarks Milj portal about the users User 1 am working at the Danish society for nature conser
106. sed SQL sub languages are Data Definition Language DDL e Creation and modification of relational schema e Schema objects indude relations indexes etc Data Manipulation Language DML 20 e Insert delete and update rows in tables e Query datain tables Data Control Language DCL e Concurrency control transactions e Administrative tasks e g setup of database users security permissions Balstr m 2012 SQL supports logical data model concepts such as relations and keys It can express common data intensive queries Listed below are some examples of typical SQL functionality e Select distinct Distinct selections are used to make sure only unique elements are selected This is only relevant in non key only selections e Join A Join is a combination of two or more tables tables can also be joined with them self This makes it possible to display and compare columns from different tables This is usually done by acommon field in the two tables so that the information is combined in a meaningful way e Full join Full joins are like joins except joins only keeps records with matches So full joins can have NULL values where there are no match where this will not be an entry in the join e Sql functions In sql it can be helpful to change datatypes For this the CAST function can be used CAST integer column AS text will convertintegers in a column to text strings Also aggregate functions can be useful These can be used to select
107. ser to search for a specific location or to search for a municipality Search Specific station Search for municipality Figure 30 The bottom bar For a better understanding of this tool an example is presented If the user types something in the box the program is automatically searching through the Facility names and shows a list with facility names that includes the searched characters For example in Figure 31the tool is used to search for o so the program displays all names that include this letter 66 Arla Foods H gelund Mej Vojens S nderborg Centralrens Mikkelborg J Hovslund Stationsby lt Troldk r _ Mojb l Fole lO Search for municipality Figure 31 An example of a search for a specific facility After one of the names from the list is selected the mapis zoomed to that specific facility The search for municipality tool works the same as the search for a specific location regarding the search action ESG 4326 coordinates 8 14451 55 76283 Search for municipality 67 oe K benhavns Kommune a a Frederiksberg Kommune N Ballerup Kommune AY A Br ndby Kommune J Lyngby Taarb k Kommu T rnby Kommune gt Vallensb k Kommune Fredensborg Kommune Gribskov Kommune Holb k Kommune Kalundborg Kommune i i i Guldborgsund Kommune Vordingborg Kommune Bornholms Regionskomm Figure 33 An example of a search for a specific municipality W
108. ster Layers are composed with pixels These are fixed with the projection and cannot be changed from the client side view side OpenLayers 2012 Overlays All the layers except the base layer are called overlays In OpenLayers there are Vector Overlays and Marker Overlays Vector overlays present data in the browser Lines polygons and other features can be drawn through the vector overlays Marker overlays display HTML image objects More capabilities for example maintenance interaction with the remote severs can be eamed from vector overlays as it gives more opportunities to present data Marker layers supports the capabilities which vector layer cannot support Mainly Markerlayer is maintained for backwards compatibility OpenLayers 2012 GeoExt GeoExt combines geospatial knowledge of OpenLayers with the user interface of Ext JS to build powerful desktop style GIS applications on the web with JavaScript The aim of GeoExt is to make a powerful and resourceful presentation style of GIS applications on the website with the help of JavaScript It is also client side web mapping with an open source extension to OpenLayers It can support toolbars map panel legends print zoom level layer selection scale etc GeoExt is used here to integrate ext interfaces with the OpenLayers as it makes possible to handle data in more presentable way In the OpenLayers legend functions are not directly available therefore GeoExt is used to build legend modulesin
109. t be in many categories The network model allows this and is therefore not really suitable for a library In relation to Wastewater facilities we have many facilities with many compounds measured and many measurements Therefore neither the 74 network nor the hierarchical model suits However the relational database has its advantages to interact across the different information levels which are required in our system The relational database model suffers on performance though due to literature Longley 2004 but not in a degree that we would have considered to replace it 5 2 Servers A number of services that can do the job that GeoServer does for the application described in this report All of them cannot be covered in this section and all of them could not possibly be tested within the timeframe of this project GeoServer is open source OGC compliant and very simple to use The administration interface makes it usable with very limited introduction Even though further assessment of alternative options might have proven useful GeoServer was chosen as the spatial data server program The performance of the server is an issue that needs to be discussed Performance of the system is one of the most important issues due to users overall impression of the application Most of the performance is independent of the server Unfortunately we did not make performance tests because of the short project period It would though have been relevant to t
110. teration over each line in the inFile line 2 This will achieve that the two indented lines of code will be run for each line in the csv document The variable 1ine will change to be the actual line read from the file An important module specifically for GIS usage is the ArcPy module import arcpy This module will allow ArcGIS functionality inside a python script For example we would be able to make a database table like this tableName table arcpy CreateTable management r C path stations3 gdb tableName arcpy AddField management tableName name STRING arcpy AddField management tableName column0 INTEGER arcpy AddField management tableName columni FLOAT This will create a table in the specified file geodatabase of the name table with three columns one string one integer and one floating point value curl arcpy InsertCursor tableName for i in dict keys rowl curl newRow rowl name i rowl column0 dict aList i 0 rowl columnl dict aList i 1 curl insertRow rowl del curl rowl This piece of code will copy the dictionary into the database file using the ArcPy added functionality 31 2 5 Web based GIS WebGIS helps to make geographical information available to the clients The internet browsers have access to GIS applications without buying the software while map services allow GIS applications without hosting them locally having the latest updates Oft
111. ters that can be parsed from JavaScript into the view So in principle we would be able to have the entire view query as sql and then parse a query But that would call for some risky Regex leaving the website open to hacking So to make things simpler the strategy is to have the view query as static yet versatile as possible The select part of the query is where the columns used are selected These have two purposes as information when a point of discharge is clicked on the map and to colour the points on the map The information shown when a point of discharge is clicked is not subject to the parametric view therefore there can be no dynamics Information to colour the points of discharge on the map on the other hand needs to be dynamic This is done by calculating one value as a function of the measured value and the limit It is needed to check whether the limit value is exceeded or not This should be done parametrically When measuring a compound like lead in the water the value should be as close to zero as possible This can simply be done by calculating n If this value is more than one the limit is exceeded But for the case of pH values this is not a good way to calculate it pH values have both a maximum limit and a minimum limit And it must be investigated if either of these is being exceeded or which is the closest to being exceeded So the math should be max minlimit value value maxlimit In order to do mean
112. the styling change so it has the name of the facility attached to the point together with the earlier defined colour The pipe between the facility and the point of discharge can be activated by the use The width of the pipe on the map is slightly thinner than the point of discharge and the wastewater facility This is done to avoid that the pipe seems more important The wastewater facilities treatment sites as opposed to points of discharge can as well as the pipes be activated The size is the same as the size of the points of discharge However the colour of the facilities is different from any of the discharge points to avoid confusion By using different visibility at different zoom levels we make sure that the user does not drown in information that is not viewable anyway If we had added all information at any zoom level it would have been confusing with too much information HTML implementation The web application is a HTML document The document consists of two parts the HTML and the JavaScript inside the HTML lt Script gt tags The application is almost exdusively running on JavaScript functionality so the HTML part of the application implementation is basically just loading files for use in the JavaScript These are e Ext JavaScripts and css Ext is extra JavaScript functionality linked to graphics files css So when new Ext form ComboBox is used in the JavaScript it is known because it is linked to additional scripti
113. the map object It is done by calling map addLayers where an individual layer or many layers are passed Finally the map s viewable area is specified Here the actual code that moves the map to the zoom centre point The final digit is the zoom level This if statement checks to see whether the map already has a centre point Basic terminologies In this subsection we define some basic terminologies Base Layers A base layeris at the very bottom of the layer list and all other layers are on top of it One may also have multiple base layers However only one base layer can be active at a time Base layer determines the projection and zoom level on the map The projections of the other layers need to be the same as base layer otherwise the base layer can be distorted Any layer can be a base layer only if it is given the Base layer property but in most raster layers the Base layer property set to true by default even though it can be changed in the layer options OpenLayers 2012 Non Base Layers Non Base Layers are alternative layers of Base Layers Therefore it performs the other tasks which Base Layers do not carry out Non Base Layers are also sometimes called Overlays Many of the Non Base Layers can be active at a time while in the Base Layer only one can be active at a time Non Base Layers do not 40 support the zoom control while some layers can support re projection to the base layer projection OpenLayers 2012 Raster Layers Ra
114. thin the text and to the right the text in the bibliogra phy Murdoch University 2011 Character references References to figures tables code samples and appendixes are used in certain ways They are numbered sequentially from the start For example figure 1 in the text refers to a figure identified as Figure 1 Tables and code samples are referred to as figures Appendixes are referred to with continuous numbers Lists of Abbreviations API Application Programming Interface CGI Common Gateway Interface CSS Cascading Style Sheets DBMS Database Management System DCL Data Control Language DDL Data Definition Language DML Data Manipulation Language ECMA European Computer Manufacturers Association EPA HDBMS HTML HTTP JSON NDBMS ODBMS OGC ORDBMS PHP RDBMS SLD SQL SQL URI URL WFS WMS www XML Appendix Environmental Protection Agency Hierarchical Database Management System Hypertext Markup Language HyperText Transfer Protocol JavaScript Object Notation Network Database Management System Object oriented Database Management System Open Geospatial Consortium Object Relational Database Management System Personal Home Page tools Relational Database Management System Styled Layer Descriptor Structured Query Language Structured Query Language Uniform Resource Identifier Uniform Resource Locator Web Feature Service Web Map Service World Wide Web Extensible Markup Language In addition to the repo
115. try like a book having more than one author This shouldinstead be described in a distinct table in order to achieve 1 normal form 2nd normal form The 2 normal form is achieved if the first normal form is achieved and if a column does not only describe part of the primary key This is only problematic if the primary key consists of more than one column Balstr m Jacobi and Bodum 2006 152 Let us say the table achieving the first normal form with the authors has book and author combined as primary key In this case a column about the date of birth of the author which is only describing part of the primary key would violate the 2 normal form Then a third table would need to be generated with information about the author with only an author id or author name as primary key 3rd normal form The 3 normal form is achieved if the 2 normal form is achieved and if no columns describe non primary key columns Balstr m Jacobi and Bodum 2006 152 Let us say that the books from the previous example contains information about the publisher This is ok but if another field describes the publisher address or publisher phone number another table must be created to include this information as it describes a non key column Structured Query Language SQL SQL is a database language that manages mainly database management systems RDBMS SQL are combinations of commands clauses expressions predicates and options The three most u
116. ts is that its JavaScript library is open source making it free for any user It can be driven easily with any server language such as PHP PERL since it is a pure client side application Maps can also be embedded directly into a plain HTML file in order to build one s own map as required Basically OpenLayers API has two concepts which are imperative to understand These concepts are Map and Layer Even though OpenLayers is JavaScript based it does not require one to be an expert in JavaScript language before using it even though knowledge of it will be very helpful in handling errors in the script OpenLayers 2012 38 OpenLayers lives on the client side One of the primary tasks the client performs is to get map images from a map server The client ask the map server for the map in the Bounding Box of the application every time a pan zoom command is issued the client makes a new request OpenLayers makes it easy to put a dynamic map in any web page It can display map tiles and markers loaded from any source OpenLayers has been developed to further the use of geographic information of all kinds OpenLayers is completely free Open Source JavaScript released under a BSD style License So it can be said that OpenLayers is an Open Source map viewing framework written in JavaScript an alternative to commerdal mapping APIs which are designed to integrate well with existing GIS Since OpenLayers uses JavaScript syntax for coding th
117. u actually can see lt font gt lt font gt applies font type and size to text and lt b gt lt b gt creates bold text and lt i gt lt i gt italidze it lt ahref www link com gt lt a gt makes a hyperlink to for example an email or webpage lt p gt lt p gt paragraph lt br gt line break Peng And Tsou 2003 A HTML page allows the user to send a model for example FORM with data to the web server in order to be processed by a server side application which generates and sends a page in response The client user can send data to the server through the main interface elements GET the parameters are encodedin the URI POST the parameters are communicated through the HTTP message ACTION specifies the URI where data are processed name of the server and location of the CGI software Commonly used form elements Text fields Radio buttons Checkboxes Submit buttons Peng and Tsou 2003 HTML5 is the 5 and newest version of the HTML standard Itis a stated goal to reduce the need of plugin based technologies such as Flash Silverlight and Java etc W3C 2012 It is an extension of the previous HTML standards Video and audio become new elements and old outdated elements are removed HTML5 has better device compatibility due to the massive development within smart phones and tablets 27 JavaScript JavaScript is a popular scripting language which makes web pages more dynamic and interactive It was invented in 1995 by Nets
118. ue limit relationship but a pseudo value used for having some limit data to work with Splitting data Data is now slimmed and ready for implementation In accordance with our database structure the data is split into two databases the Facility database and the Measurement database Each record is assigned a unique ID attached While one facility has many measurements each measurement gets its corresponding facility ID attached as well 59 The split is made using Python scripting The input file is the output file from the previous processed CSV file We start by defining the table names We use the function CreateTable_management which is a part of the ArcPy module The demanded function parameter is a workspace and the table name This creates an empty ArcGIS table By using the function Addfield_management we create field in the empty table The necessary parameters are the table name the fieldname and the data type tableName Facilities arcpy CreateTable management r C Skole 7 sem data gdb tableName arcpy AddField management tabl me outy FLOAT arcpy AddField management tableName type INTEGER This is an excerpt there are more actual fieldsin the table See Appendix 8 2 Split data arcpy AddField management tableName f id INTEGER arcpy AddField management tableName name STRING arcpy AddField management tableName muni_code INTEGER arcpy AddField management tableName
119. vation In my daily work keep an eye with the quality of the water in Denmark It can provoke a catastrophe if wastewater that exceeds the limit values enters the nature Easy access to the datais therefore a huge advance in my work to monitor wastewater User 2 am working at the Danish Nature Agency My organisation has the governmental responsible to secure that wastewater is not destroying our environment A better access to data is therefore expedient in my daily life User 3 am an ordinary citizen and live by the sea right next to a point of discharge from a wastewater facility This is normally not a problem due to the good quality of deaning at the wastewater facility However before taking a swim would like to be able to see the measurements of each compound Therefore have a huge interest to be able to see data about the point of discharge Concluding on the three users we have two main user groups the professionals and the citizens In a professional matter access to the data is quiet political and seems necessary However the system is made public for all so a benefit to publish it is that citizens can get information about the water that they use for recreational activities It is expected that each user group has different preferences to the way to interact with the system This is mainly caused by their existing knowledge on the Wastewater field A citizen is expected to have a curious way of acting in the application whil
120. x and dynamic typing together with its interpreted nature make it an ideal language for scripting and rapid application development in many areas on most platforms Swaroop 2005 1 Python has several key features It is a simple language and easily readable Pythonis extremely easy to get started with as it has very simple syntax Python is a Free Libre and Open Source Software FLOSS It is 30 easily available It does not require high level of language Python is object oriented language where it combines data with functionality Python programs are easily extensible to the other languages Python has a standard library which has modules for every task Swaroop 2005 Common language examples Python scripting can be used for file handling For this feature it is relevant to import modules Modules are language and functionality extensions that can be imported to extent the features of a python script Consider the following code infn r C Users Thomas Documents My Dropbox Wastewater data working data dataslimmed csv inFile open infn r This piece of python code will allow the script to read the document dataslimmed csv and process the data it holds If the dataslimmed csv is a semicolon separated table the data can be inserted into a dictionary like this dict for line in inFile aList line split dict aList 0 aList 1 len aList inFile close Notice the use of the for loop starting the i
121. y GeoServer creates maps in different output formats through following Web Map Service WMS and Web Feature Service WFS standards GeoServer operates data through workspaces stores layers and styles GeoServer also integrates which make map operation GeoServerA 2012 36 localhost 8080 geoserver web e 189 Logged in as admin al Logout GeoServer __ co Welcome About amp Status dl Server Status GeoServer Logs This GeoServer belongs to The ancient geographes INC Service Capabilities Welcome Contact Information wes About GeoServer 39 Layers Add layers uno 1 1 1 t ed a 12 Stores Add stores WES Ll Layer Preview 11 Workspaces Create workspaces 1 0 0 E Workspaces 1 1 0 Stores WMS T This GeoServer instance is running version 2 1 3 For more information please contact the S Layers 1 1 1 administrator W Layer Groups 1 3 0 Cached Layers TMS Styles 1 0 0 WMS C Services 111 amp wcs WMTS i wFs 1 0 0 la wms Settings 3 Global GeoWebCache Ela El coverage Access Security amp Users Figure 14 GeoServer admin page A workspace groups similar type of data It is a container that contains similar types of data If there presents no name conflicts among the layers then it is possible to use identical layers in different places Normally workspaces are presented by a prefix to a layer or store name Stores layers layer groups all must have an assodated workspace
122. y handle operational layers Very Thin Client Best Practice Very Thick Client GIS Database To GIS Database E Data gt Intemet lt gt mene Map Query Client Client Analysis gt ntemet a M gt m Map Query Analysis Figure 10 Distribution of tasks of the very thin and thick layer and how it can be best practiced Fu and Sun 2011 41 HyperText Transfer Protocol HTTP is the main way tolink web clients and web servers by exchanging files between the web browser and web server As a message carrier HTTP carries user requests from browsers to servers and takes the requested information text graphic images sound video and other multimedia files from servers back to browsers To communicate between the web client and web server it uses different commands or methods Each Web Server has an HTTP domain to listen to HTTP requests from the web browser When HTTP daemon receives the request it processes the request based on some standard methods These methods include GET HEAD PUT POST REPLY etc Peng and Tsou 2003 GET is the most commonly used method in retrieving whatever data are identified by the URL induding running scripts It is also used for searches HEAD represents only the HTTP headers not induding the actual document body PUT stores the data to the supplied URL in the Web server The URL must already exist POST and REPLY should be used for

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