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Feasibility study on automated geo

1. Individual Sentences Translate GPS Data GPGSA Sentence GPRMC Sentence Split Sentences Split Sentences GPRMC words GPGSA Extract Extract _ Precision coordinate information information Coordinates PDOP value Coordinates Precision l Figure 1 4 Detailed DFD for GPS interface The external agents in the GPS interface DFD Figure 1 4 are the surveyor who provides input into the setup of the interface i e selects which COM port the GPS receiver sends the GPS sentence to The other external agent is the GPS receiver The GPS receiver converts the incoming satellite information and converts it to a set of GPS sentences which provide the positional information on which the remainder of the processes are based The outputs from the process are three variables latitude longitude and PDOP which are made available for the rest of the application Automated Geo referenced data entry for agricultural land use 110 1 4 Database Design There are three databases linked to this application The primary one is the output database where all the field survey point data is saved The second and third databases store the classification reference data The primary key for the project output database is a combination of the PSU and SSU identities all other point information is linked through this primary key Within the database there are six data tables five of these hold the point data and th
2. 13 0 428020823 52 004016952 0 428021494 52 004016880 0 047 14 0 428019380 52 004016047 0 428021055 52 004014707 0 188 15 0 425734005 52 004294064 0 425733280 52 004294054 0 050 21 0 425733476 52 004293648 0 425733159 52 004294412 0 088 22 0 426231210 52 006248424 0 426230588 52 006248265 0 046 23 0 426232486 52 006249076 0 426228889 52 006248027 0 273 24 0 428579800 52 005823641 0 428562329 52 005834203 1 679 25 0 428581503 52 005821582 0 428583153 52 005824538 0 348 3 4 Discussion The field test was a success The application recorded all of the required information including the sample point coordinates from the GPS This information can now be incorporated in to a GIS for further analysis The field test did raise a few questions that can be looked at in the future One concern was whether the position should be recorded if the sample point is inaccessible If you do record the coordinates for the location that you are at then you can t use them to position the sample however if you don t record them then returning to the point at another time is difficult The GPS coordinates recorded from the NMEA signal compare very well to the coordinates recorded through TerraSync There are some minor variances between the two These can be attributed to the recordings being taken at slightly different times as it was impossible to record the positions simultaneously 3 5 Conclusion The a
3. Transfer All to complete the transfer process During data transfer a progress bar will be displayed showing the progress on the task Once file transfer is complete a file transfer completed message will be displayed e Dismiss the transfer complete message by clicking close During transfer a log file txt is created in the project folder Should transfer be unsuccessful it is recommended that this file is opened from either the transfer failed window or My Computer Inspection of this file is recommended to determine why transfer was unsuccessful Survey point locations As the survey point locations are all predetermined according to the sampling scheme these data can be transferred onto the GPS unit to aid navigation The following steps assume that the survey point locations are held in a georeferenced shapefile projected to the same coordinate system as the raster image files Two methodologies can be followed for the transfer and display of these survey locations The first methodology uses the same approach as the vector background files in which the shapefile is converted to a Trimble format via the import function in Pathfinder Office prior to transfer to the unit Alternatively the shapefile can be transferred to the GPS device in its current format conversion to a Trimble data file format is then achieved within the TerraSync software To allow further exploration of the function of TerraSync the second methodolo
4. and unsuccessful bottom image connection to a device If a connection cannot be established after re clicking the connection button check all cabling and ensure that the ActiveSync guest or partnership connection is properly established Once a successful connection has been established the data dictionary and raster maps can be transferred e In the Data Transfer dialog select the Send tab to enable transfer of data to the device e Once the Send tab is selected click the Add drop down menu Specifying the data dictionary e Select Data dictionary from the Add drop down menu e Inthe Open dialog which opens automatically browse to and select the survey data dictionary e Click Open The data dictionary file should now be listed in the file transfer dialog Specifying the raster images e Select Background from the Add drop down menu e In the Open dialog browse to and select the appropriate raster image s e Click Open The raster image file s should now be listed in the File Transfer dialog Specifying the imported vector files e Select Data File from the Add drop down menu e Inthe Open dialog browse to and select the imported vector file 1mp Automated Geo referenced data entry for agricultural land use 66 e Click Open The vector file s should now be listed in the File Transfer dialog Transferring the files e Click
5. e Click OK to accept the coordinate system and return to the parameter setup window ESRI Shapefile Tab e Ensure that the Export Tracking Themes option is left unchecked e Click OK to accept the setup parameters and return to the export utility e The changes made to the export parameters should be reflected in the summary at the base of the Export Utility dialog e Click OK to accept the parameters set and proceed with the export The export utility will proceed with the export process and the creation of a series of shapefiles A series of files are created as a unique shapefile is created for each feature type i e the land use feature and third stage LCCS dichotomies These files are named according to the feature label specified in the data dictionary e When export is complete an Export Completed dialog will be displayed This includes a summary of the number of features exported Ensure that the appropriate number of features i e the number of survey points in the file have been read and exported If there is a discrepancy between the number of features read and number exported the export parameters in particular the positional filter properties should be checked e Click Close to dismiss the Export Completed dialog It is important to note that the file naming conventions used in the export are standardised and set by the software As a result on running a second export process
6. e Data Entry Main flow of events The surveyor is able to add data to the selected project including area and sample ID s general sample point details land cover details land use details and photograph details When the surveyor starts recording each point the GPS position is recorded and added to the database Exceptional flow of events If the sample point reference already exists the user will be prompted to check and re enter the reference Exceptional flow of events If the area sample reference already exists the user will be prompted to check and re enter the reference e Close Project Main flow of events Surveyor selects close project All records are saved to the database and the surveyor is returned to the main page Automated Geo referenced data entry for agricultural land use 105 Exceptional flow of events If the surveyor selects add another sample point they are returned to the beginning of the data entry process 1 1 2 GPS Interface Main flow of events The GPS signal is received by the GPS receiver and then translated to produce latitude and longitude values and a PDOP figure for the precision of the GPS position Live coordinates are displayed along with the PDOP value GPS coordinates are collected over the period of the point data collection and averaged to increase the positional accuracy Exceptional flow of events If there is no data at the selected port the system raises a prompt and returns the s
7. e From the Options list menu select Set Nav Target followed by the survey point which will be identified in the menu via its unique identification number followed by the name of the datafile i e 9 survey points location The navigation target symbol should be displayed over the survey point to which you wish to navigate Automated Geo referenced data entry for agricultural land use 81 Navigating to the target location e Now that the navigation target is set move to the navigation section of TerraSync select Navigation from the section list menu e Confirm that the navigation target is set by ensuring that the set target reads Target ID Survey location Point at the top of the navigation window If the display reads Target No Target the target has not been set successfully return to the map section and reset the navigation target using the previous instructions Prior to starting the navigation section the close up range should be set e Select Navigation Options from the Options list menu in the navigation section The navigation dial will be replaced by the navigation options form Figure B4 6 Figure B4 6 The navigation options form and close up range Trimble 2006 e The close up range is specified by typing a value into the Range drop down box The most appropriate range for use of the close up screen is largely a function of landscape terrain and surveyor pref
8. from the subsection list menu Figure B5 3 Figure B5 3 Generic data collection form The data collection form will vary according to the data dictionary which forms the template of data collection the form shown in Figure B5 3 is based on a generic dictionary Characteristics common to all data collection forms irrespective of data dictionary are that that they contain at least one feature which is either a point line or polygon and that they can contain multiple features and multiple feature types Creating a new feature In the case of this survey the data dictionary and therefore data collection form contains a series of point features These independent point features are defined to represent the land use classification and third stage of the dichotomous phase of the FAO LCCS classification gt Cultivated and Managed Terrestrial Area s gt Natural and Semi Natural Terrestrial Vegetation gt Cultivated Aquatic or Regularly Flooded Area s Natural and Semi Natural Ac juatic or Regular ly Flooded Veg gt Artificial Surfaces and Associated Area s gt Bare Area s gt Artificial Water bodies Snow and Ice gt Natural Water bodies Snow and Ice gt Land use classification Greyed items are not available in the current demonstration data dictionary Behind each of these features is a set of attributes which are feature specific and determine the types of data which must be recorded at the survey location Automated
9. Area Frame Sample Designs A Comparison with the MARS Project Agricultural Statistics 2000 Washington March 18 20 Pp261 277 Cotter J and Nealon J 1987 Area Frame design for Agricultural Surveys U S Dept of Agriculture Nat Agr Stat Serv Cowell J 2002 Essential VB NET London Springer Verlag Di Gregorio A 2005 Land Cover Classification System Classification concepts and user manual Software version 2 FAO Rome Delinc J 2001 A European approach to area frame survey Proc of the Conference on Agricultural and Environmental Statistical Applications in Rome CAESAR June 4 8 Vol 2 463 472 Duhamel C 1998 First approximation of a land use classification Report to the FAO Food and Agriculture Organization of the United Nations Rome ECE UN 1989 Standard international Classification of Land Use Commission and Economic Commission for Europe UN Geneva Eurostat 2003 The LUCAS Survey European Communities Luxembourg FAO 1996 Multiple frame agricultural surveys Volume 1 Current surveys based on area and list sampling methods FAO statistical development series n 7 FAO Rome 119pp FAO 2005 Land cover classification system Classification concepts and user manual software version 2 FAO Rome FAO 1998 Multiple frame agricultural surveys Volume2 Agricultural survey programmes based on area frame or dual frame sample designs FAO statistical development series n 10 F
10. Area feature Point feature GPS trail Line feature Navigation start AA ree a Command bar Scale Figure B4 1 Main elements of the map section within TerraSync Trimble 2006 When open the Map section will illustrate features associated with the current data file the current GPS location and the navigation start and finish locations if set In addition raster images and vector datasets can be added to the display Tools for controlling the display of the Map section are located on the command bar and within the three list menus Automated Geo referenced data entry for agricultural land use 75 Command Bar Tools elt hblelele The command bar tools allow panning and zooming within the map display enabling the user to focus on particular features Pan tools Pan the map half of its width or height in a left right upwards or downwards direction a Zoom tools Zooming tools which magnify or reduce the map scale focused on the centre of the map display a Zoom to extent Resets the zoom factor to enable viewing of all data files within the view Map Tools 21 Further map display navigation tools are located within the map tools list menu A Select tool Using the select tool tap on map features to select or highlight them PE Interactive zooming tools When these tools are selected either tap on a single point or click and drag a rectangular area to magnify or reduce the scale of the map display focused on th
11. Pesticides Fungicides weed control Biological control Nutrients Organic fertilizer Mineral fertiliser Other soil amendments Erosion Tillage Levelling contour tillage terracing Cover crops Crop residue incorporation Power Sources CS1 CS2 CS3 CS4 CS5 CS6 PW1 PW2 PW3 PW4 NU1 NU2 NU3 ERI ER2 ER3 ER4 Water Management Irrigation Rainfed Non equipped cultivated wetlands amp inland valley bottoms Non equipped flood recession cropping Equipped cultivated wetlands amp inland valley bottoms Equipped flood recession cropping Full partial control irrigation surface sprinkler localized Spate irrigation Adequate drainage of excess water Other LIVESTOCK Livestock Types Asses Beehives Cattle Chickens Goats Pigs Poultry Birds Sheep Cattle Management WM1 Open grazing WM2 Fenced pastures WM3 Stall fed WM4 Improved pastures WM5 Significant share of imported breeds WM6 Water resources adequate access WM7 Feed adequate access WMS8 Credit adequate access WM9 Extension services adequate access Veterinary services adequate access Drugs vaccinations adequate access LV_1107 LV_1181 LV_866 LV_1057 LV_1016 LV_1034 LV_2029 LV_976 CM10 CM11 Automated Geo referenced data entry for agricultural land use 13 Manual PS1 Animal PS2 Mechanized means PS3 Automated Geo referenced data entry for agricultural land use 14 A
12. button check all cabling and ensure that the ActiveSync guest or partnership connection is properly established Once a successful connection has been established the almanac can be transferred e In the Data Transfer dialog select the Receive tab to enable transfer of data from the device e Once the Receive tab is selected click the Add drop down menu select Almanac e The Data Transfer window will automatically open requesting the output location and file name for the transferred file Leave these settings at the default values e Click OK The almanac should now be listed in the files to receive section of the Data Transfer window e Click Transfer All to initialise the transfer e Click Close to dismiss the Transfer Complete message e Close the Data Transfer utility and return to the main Pathfinder Office window Quick Planning e Open the Quick Plan tool using either the main menu Utilities Quick Plan or toolbar icon On opening the Quick Plan tool a wizard will automatically open to aid setup of the survey parameters e When prompted select the appropriate date for which the survey is planned e Click OK to accept the date The wizard will automatically open the Edit Point dialog box The Edit Point dialog allows selection or definition of a point at which GPS observations are planned Quick Plan will calculate satellite
13. if you are not currently viewing the Status section you should move to this section using the section drop down The Status section contains a series of elements which indicate the current status of the GPS signals and receiver Satellites being tracked North indicator but not being used to R compute positions Horizon Satellites being used to Minimum compute positions elevation 43 2950 879 17203354 147 E Current position wes 1904 esate aay Figure B3 1 The Status section of TerraSync as a means of checking the GPS status Important elements you should consider in the Status section are Figure B3 1 Automated Geo referenced data entry for agricultural land use 73 Satellite locations The central diagram of the window indicates the location of the GPS satellites relative to your position and the horizon depicted by the outer black circle Each satellite is represented by a small numbered square this number is unique for each satellite within the GPS constellation If the square is filled in black in colour then the satellite signal is sufficiently strong and this satellite is being used to compute the current location Alternatively unfilled or white satellites are those being tracked but not used to compute a location at the current time The satellites being used will vary according to their location in the sky satellites must be above the specified elevation mask indicated by the red li
14. the output filenames will already exist hence an overwrite files warning will be generated To prevent file overwrite the original export files should be removed from the export folder or renamed e Using ArcCatalog or My Computer navigate to the export sub folder of the project folder A series of shapefiles should now be present Automated Geo referenced data entry for agricultural land use 101 Appendix C Automated Geo referenced data entry for agricultural land use 102 Appendix C Bespoke GPS application 1 Design 7 7 Introduction The requirements for any field data collection application are defined by the structure and methodology of LUCAS Based on the FAO project needs and the LUCAS methodology requirements the following list has been created This list provides a basis for assessing the abilities of existing software applications as well as providing a basis for development of a task specific application if required e Data o ls field survey input and recording supported o Hierarchical data structure o Enforce data integrity o Dual themed Land Use and Land Cover o Point recording o Universal data format o Data backup e GPS Integration o DGPS compatibility o Recording of precision measurements e Usability o User friendly o User driven e Cost o Low cost Automated Geo referenced data entry for agricultural land use 103 A detailed design of the final application is required to maintain the focus of the app
15. window will open by default If it does not open then select File Projects In this dialog an existing project can be opened if a suitable project for the current work has been created or create a new project In this case the project created prior to field survey will be re opened e In the Select Project window ensure that the name of the project created prior to field survey is selected in the Project Name drop down list e Click OK to close the Select Project dialog Automated Geo referenced data entry for agricultural land use 91 File Transfer e The Data Transfer module is opened from the main menu Utilities Data transfer or using the shortcut on the Utilities toolbar Er As the data transfer utility has been used previously the GIS Datalogger on Windows CE should be listed in the Device section e Ensure the GIS Datalogger on Windows CE is selected in the device window and a connection has been established If connection has not been successful refer to section 1 of this appendix for details on re attempting the connection e In the Data Transfer dialog select the Receive tab to enable transfer of data from the device Once the Receive tab is selected click the Add drop down select Data file Locate and select the rover file in the subsequent dialog box which is opened Click OK The selected rover file should now appear in the Files t
16. 0 5 or 1 the amount of land use land cover category h in the SSU j within the PSU I n number of SSU within the PSU I di number of pairs of observation points taken Uni indicative variable associated to the calculation of the variance of the considered category In this formula of variance u U _ 18 zero if both land covers on the SSU are same ones If both land covers differ from neighbouring SSU then u u _ is one Otherwise u u _ is 0 5 Automated Geo referenced data entry for agricultural land use 129 Appendix D3 Sample size and effective sample rates for the LUCAS 2006 methodology in Sierra Leone Class Value Sampling rate Replicates Master sample Sample Effective Sampling rate Closed evergreen lowland forest 1 10 8 878 84 10 Degraded evergreen lowland forest 2 30 24 59 18 31 Submontane forest 3 10 8 2 1 50 Mangrove 6 10 8 744 69 9 Mosaic Forest Croplands 7 50 41 13718 6958 51 Deciduous woodland 10 10 8 2056 200 10 Deciduous shrubland with sparse trees 11 20 16 399 83 21 Closed grassland 13 40 32 1 1 100 Irrigated cropland 20 50 41 7 1 14 Waterbodies 26 10 8 17 2 12 TOTAL 17881 7417 Automated Geo referenced data entry for agricultural land use 130 Appendix D4 Final Sample for the implementation of the LUCAS 2006 methodology in Sierra Leone Legend 0 25 50 100 150 200 re 5 Background aa Deciduous woodland la Closed evergreen lowland forest Deciduous shrubland with s
17. Each replicate is selected up until the correct number of points is selected for each stratum according to the sampling rate identified in table 4 4 1 Appendix D describes the implementation of the 2 LUCAS approaches for Sierra Leone The LUCAS 2003 approach results in 220 PSUs with a total of 2200 SSUs while the 2006 approach would result in 7427 sample points by applying exactly the same sampling rates as the ones used for Europe This is based on applying a stratification derived from The Global Land Cover GLC 2000 classification Global Land Cover 2000 2003 This was used as an example and in practice a more detailed assessment of each point should be done based on the interpretation of satellite imagery and or aerial photography Point sampling is particularly suitable to the African environment because it does not require the identification of parcel boundaries as is the case for the other approaches Secondly because it is point based it is also particularly suited to the use of a GPS data collection device as there is a direct link between the GPS position and the point sample 4 5 Stratification As mentioned above stratification is one of the methods used to reduce variance by varying the sampling intensity depending on the stratum e g there is no need to have a high sampling rate in water areas or bare areas because there will be little variation in terms of land use however there will be a need to increase the sampling inte
18. Fragmented Striped Cellular Parklike Patches II D Leaf Type Broadleaved Needleleaved Aphyllous E Leaf phenology Evergreen Semi Evergreen Deciduous Semi Deciduous Mixed Mixed for Forbs Graminoids Annual Perennial II F Stratification Second Layer Second Layer Absent Second Layer Present Woody Trees Shrubs Herbaceous B4 B15 B11 B12 B13 Cl C2 C4 C5 C3 D1 D2 D3 El E4 E2 E4 E3 ES E6 E7 F1 F2 F3 F4 F5 F4 G Cover Second Layer Closed To Open Closed gt 70 60 Open 70 60 20 10 Sparse 20 10 1 H Height Second Layer 7 2 m for Woody gt 30 3 m gt 14 m 14 7 m 7 3 m 5 0 3 m 5 2 m 2 0 5 m lt 0 5m 3 0 03 m 3 0 3 m 0 3 0 03 m F Stratification Third Layer Third Layer Absent Third Layer Present Woody Trees Shrubs Herbaceous G Cover Third Layer Closed To Open Closed gt 70 60 Open 70 60 20 10 Sparse 20 10 5 F7 F8 F9 F10 G1 G2 G5 G6 G7 G3 G8 G9 G10 G4 G11 G12 F1 F2 F3 F4 F5 F4 F7 F8 F9 F10 Automated Geo referenced data entry for agricultural land use 17 Land Cover Classification System A12 Nat amp Semi Nat Terrestrial Veg H Height Third Layer 7 2 m for Woody gt 30 3 m gt 14m 14 7m 7 3m 5 0 3 m 5 2 m 2 0 5 m lt 0 5m 3 0 03 m 3 0 3 m 0 3 0 03 m Code G1 T FLORISTIC ASPECT G2 Single Plant Species G5 Dominant Species G6 Most Frequent Species G7 G
19. Geo referenced data entry for agricultural land use 87 Upon reaching the survey location when recording the new feature position and attributes the surveyor must initially record the land use and subsequently the LCCS information In terms of the LCCS classification the surveyor must determine which of the LCCS classification descriptions best describes the survey location as this will determine the point feature type created and required attribute fields e Locate the Land Use feature in the TerraSync data collection form Select the point feature using a single click or tap This point feature should be highlighted e Click the button labelled Create The logging position form will automatically replace the data collection window Whenever the maximum PDOP is below the specified value GPS positional data is recorded for this survey location As a result the surveyor should stay stationary at the point and ensure that the GPS antenna remains static Collecting GPS positions As stated previously as soon as the new feature is created GPS logging will commence This is indicated by the additional logging status symbol l 2 in the main TerraSync status bar This symbol is accompanied by an incrementing number indicating the number of GPS positions currently recorded at the point Ideally to improve accuracy a number of GPS positions should be recorded at each survey location to allow averaging in the final position determination The d
20. P10 P3 P11 P12 P13 P4 P14 P15 P16 Q Erosion No Visible Erosion Visible Evidence of Erosion Water Erosion Sheet Rill Gully Wind Erosion Mass Movement R Water Quality Fresh Water Brackish Waer Saline Water Q1 Q2 Q3 Q6 Q7 Q8 Q4 Q5 R1 R2 R3 U Vegetation Scattered Vegetation Present Woody Herbaceous Forbs Graminoids Lichens Mosses Lichens Mosses W Crop Cover Density Permanent Life Forms Closed Cover gt 70 60 Closed Cover 70 60 20 10 Sparse Cover lt 20 10 Temporary Life Forms High Crop Density gt 60 Medium Crop Density 60 30 Low Crop Density 30 15 LA MN YN SESESEESESS w W2 W3 W4 W5 W6 Automated Geo referenced data entry for agricultural land use 22 3 Classification implementation within a GPS device 3 1 Introduction One of the purposes of this project is to demonstrate the acquisition of data required for land use and cover classification using standard GPS equipment Section 5 compares the range of GPS units available and highlights their applicability to the requirements of this project Essentially what is required is the ability to record data about land use and cover in the field at specific sample point locations Windows CE based GPS units offer the opportunity to develop bespoke data entry applications However the remit of this project requires the use of data entry products supplied as a standard product with the GPS unit Th
21. additional processing step is required in the case of vector data prior to display This step carried out using the import utility is required to convert the vector file into a Trimble data file format imp e Ensure that the vector data is georeferenced and available on the desktop PC e Within the current Pathfinder Office project open the import utility from the main menu Utilities Import or by using the shortcut on the Utilities toolbar The Import utility dialog should appear similar to Figure B2 2 Automated Geo referenced data entry for agricultural land use 63 la Input Files Folder E ALiz Selected Files Cancel centrenontsU5kmshape shp Browse Help Output File E Li2z 6110911a imp Browse m Choose an Import Setup Sample ESRI Shapefile Setup y Format ESRI Shapefile Type of Import Features with Data Dictionary Dutput Option Combine input files into one output file GIS Coordinate System Site System United Kingdom Zone Ordnance Survey National Grid Datum Ordnance Survey Coordinate Units Meters New Delete Properties Figure B2 2 The Import utility dialog e To select the files for import click the Browse button within the Input Files section of the dialog e Navigate to and select the appropriate vector file in the Select GIS Data Files dialog Click Open to accept the selected file and close the dia
22. application functions as it should and meets the requirements laid out in section 1 1 This field test will result in a dataset that contains all the recorded data that is required from the chosen survey methodology Methodology The LUCAS methodology detailed in section 4 4 of the main report will be used as a basis for this field test The test will be carried out on a PSU site adjacent to the university site in Silsoe Each SSU Figure 3 1 will be visited and observation land cover land use and photographic details will be recorded The methodology aims to test the functionality of the GUI the database interface and the GPS interface The resultant database will be displayed providing evidence that the application records and saves the required information Automated Geo referenced data entry for agricultural land use 120 LUCAS Training Site Silsoe Cranfield Silsoe 4 0 45 90 180 270 360Metefe SSUKey 11 12 13 14 15 X 507200 507500 Y 507500 1 235346 X 507800 X 508100 1 235045 Y 236046 Source Farmer 2006 Figure 3 1 Field test sample points 3 3 Under a separate investigation a comparison will be made between positions recorded using the Field Data Collection application and TerraSync Positions will be recorded using the raw GPS data which will not be corrected in any way Five survey points will be chosen and GPS coordinates are recorded twice per application at each point A difference in distance bet
23. associated with each feature that can be selected from a drop down list These characteristics are stored in a data dictionary which can be customised using the accompanying software installed on a PC The data dictionary can then be uploaded to the GPS to be used in the field There are 3 types of mapping GPS device e Separate GPS receiver GPS antenna and data logging devices using a field computer These units offer the greatest level of accuracy and flexibility but are also the most expensive They would be too costly and complex to configure and operate for the purpose of a land use survey Units amount to around US 10 000 Automated Geo referenced data entry for agricultural land use 41 e Integrated GPS units running the Windows CE operating systems These units are fully integrated combining the GPS receiver antenna and data logger into a single handheld unit However they still offer the capability of connecting to a separate GPS antenna for better accuracy Examples of such units are the Topcon GMS 2 Thales Magellan MobileMapper CE and Trimble GeoXM XT Figure 5 4 1 In addition to the cost of a unit at least US 2500 the cost of the GPS data collection software PC interface and configuration software need to be added e Integrated GPS unit running proprietary software These units are less configurable than the above but have the benefit of being much cheaper at less than US 2000 for a Thales Magellan MobileMapper shown in fig
24. be environmental e g climate landform altitude soils and or specific technical attributes e g crop type soil type salinity Land use refers to the human activities which are related to land making use of its resources and having an impact upon it Young 1998 It is the classification of land use that forms the main focus of this section of the report The following subsections propose a demonstration data dictionary that is based upon the classifier principle outlined above The land cover and land use classification methodologies below have been selected on the basis of their potential incorporation into a field data collection device They meet the requirements set out above and represent much of the current thinking on land cover and land use classification 2 2 Land Use Classification 2 2 1 Background As has been stated by several authors Duhamel 1998 de Bie 1996 Young 1998 no universally accepted land use classification has been developed Duhamel 1998 in particular analyses the development of land use classifications and his findings are neatly summarised in Jansen 2005 However many classifications have been formulated within individual countries to meet local needs Class names may be the same or similar between different classifications but detailed examination may reveal distinct definitional variation This feature militates against their use as a reference or international classificat
25. containing the coordinates for each SSU would provide a method of navigating to the point as well as providing a quality check for the record position If the difference between the two was less than a specified threshold then the point could be classed as visited If it was above then the point could be classified as observed from distance or within a forbidden zone e Placing the GPS interface component within a separate class enabling it to be included in other application easily e Increase the application adaptability to include other classification systems e Addition of a delete button enabling the user to delete a sample point e Increase the control the user has over the GPS interface i e provide control over how often the GPS data is collected e Allow the recording of positional data in a range of different datums e Incorporate more GPS information such as the number of satellites in view Automated Geo referenced data entry for agricultural land use 125 Appendix D Automated Geo referenced data entry for agricultural land use 126 Appendix D1 GLC2000 for Sierra Leone 0 25 50 100 150 200 250 Kilometers Legend E Background Deciduous woodland Closed evergreen lowland forest Deciduous shrubland with sparse trees N C Degraded evergreen lowland forest C Closed grassland En Submontane forest Irrigated cropland W E EA Mangrove Waterbodies pa Mosaic Forest Croplands Cities S
26. cover classes by combining sets of hierarchically arranged classifiers Di Gregorio 2005 Of particular interest to land degradation studies LCCS can also include environmental attribute information such as climate landform altitude soil lithology and erosion LCCS does not contain any provision for collecting land use information however the FAO does have a land use database which could be utilised to generate a land use classification system 4 3 Survey Methodology There are opportunities for development of the survey methodology As discussed in section 4 of the main textErreur Source du renvoi introuvable LUCAS within Europe has evolved and now instead of using an 18km grid a 2km grid is used This change has resulted from the lessons learnt during the first LUCAS surveys Automated Geo referenced data entry for agricultural land use 124 The same can be true for carrying out LUCAS within Africa The selected methodology for this project is a starting point from which lessons can be learned Changing the size of the sampling grid or increasing the sample points are a future development that may improve the effectiveness of the survey 4 4 Software As discussed in section 3 4 there are many improvements that can be made to the application Some of the most significant future developments are as follows e Record the carrier phase signal to allow post processing of the positional information e Inclusion of a file
27. data integrity can be ensured with the implementation of drop down selection and required fields during data assignment As a result of this construction data dictionaries have the advantage of being able to provide a means of structuring data collection tasks according to the required features of a survey and ensuring data integrity by specifying allowable data inputs The data dictionary editor The data dictionary editor utility Figure A3 1 available within Pathfinder Office provides functionality for the creation and editing of new or existing data dictionaries lolx File Edit Options Help DOsat elt y Name Comment Features Attributes Default Feature Settings Press F1 for help Figure A3 1 The data dictionary editor utility The creation of a data dictionary within this utility is based on the definition of features and their attributes Automated Geo referenced data entry for agricultural land use 50 Creating a new data dictionary Open the data dictionary editor by selecting Data dictionary editor from the Utilities menu in Pathfinder Office By default the editor will open with a blank data dictionary allowing the creation of a new definition Specify a name for the dictionary at the top of the editor window Creating a new feature The initial step in the creation of the data dictionary structure is the creation of a new feature to which attributes can be assigned Featu
28. in the Export Menu Attributes As section click in the radio button adjacent to Code Value 1 to ensure it is selected This is very important as the data dictionary has been constructed to allow the export of coded values As a result each of the attribute fields in the dBase file will contain an alphanumeric code based on the recorded data instead of a text description For example the alphanumeric code of A1 in the life form main crop field of a cultivated or managed feature is indicative of broadleaved trees The base of the dialog contains a series of generated attributes which can be derived by the software from the GPS data These generated attributes are grouped according to feature specific categories e From the All Feature Types group of the generated attributes section select PDOP by checking the appropriate check box As a result an additional field will be added to the dBase table which contains the average PDOP value for each feature e From the Point Features group of the generated attributes section select Horizontal precision The generated field values give an estimate of the horizontal precision of the averaged position for each feature This field is a distance measure the units of which will be set in the Units tab The line feature and area feature groups can be disregarded as neither of these feature types are relevant to the survey The Attributes tab should appear si
29. labelled Pause S482 Logging of GPS positions will now be paused allowing the surveyor to move from the survey location A pause in logging is indicated by a flashing pause symbol in the TerraSync status bar 1 e To continue logging GPS positions click the button labelled Resume Resume po The logging status symbol will revert back to a pencil with incrementing numbers to indicate that logging has resumed l2 Completing Feature Creation When the attribute fields for the feature have been completed and sufficient GPS positional data collected the feature can be stored within the data file e Click OK within the logging data form MMMM e As the Confirm end feature parameter was set to Yes prior to data collection in the GPS setup a prompt is displayed to confirm that the user wishes to close and store the feature e Click OK to store the feature and return to the data collection form Note if OK has been clicked by mistake selecting cancel will return to the logging screen Subsequent to the collection of land use characteristics at the sample point the LCCS descriptors for the same location should be recorded This is achieved via the creation of a second feature based on the LCCS classification at the same sample point e Based on the LCCS descriptions determine which of the dichotomous phase class descriptions best describes the survey location e Locate the appropriate LCCS feature in th
30. of the data dictionary however means that additional default features are also available from the data collection menu of TerraSync Figure 3 3 1 These default generic features contain no data collection parameters other than feature identification and are primarily used Automated Geo referenced data entry for agricultural land use 26 for positional recording As these features are not relevant to the current survey task they would ideally for neatness and consistency be removed However this is not possible Surveyor training or a user guide is therefore required to identify these spurious features and inform the user that they should be ignored during data capture Attribute and criteria recording The third dichotomous level features of LCCS and the land use classification are each characterised by a series of attribute fields each of which are represented in the data dictionary Each attribute field contains a series of criteria represented by a text descriptor and unique code Table 2 1 Using the built in functionality of the data dictionary data input can be standardised by presenting the surveyor with data field specific drop down attribute lists Such an approach ensures that the surveyor can only input valid criteria and eliminates potential errors arising from spelling or data input mistakes A limitation of the Trimble data dictionary is that these drop down menus are hardwired on data dictionary creation and are not conte
31. processing correction has been applied to the data all positions including uncorrected must be exported Check the Uncorrected option in the Include positions that are section The Position Filter tab should appear the same as Figure B6 4 Automated Geo referenced data entry for agricultural land use 96 Export Setup Properties Sample dBASE Setup x Data Output Attributes Units Position Filter Coordinate System dBASE Position Filter Criteria Filter by GPS Position Info Minimum Satellites 20 3 or more SWs y Maximum PDOP Any Nl Maximum HDOP Any y itions That Are d V Real time Carrier Float IV Ply Code IV Postprocessed Carrier Float IV Realtime WAAS IV RTK Fixed IV Realtime Code IV Postprocessed Carrier Fixed IV Postprocessed Code Filter By Precision 68 confidence tal Precision Any Vertical Precision Any IV Include Non GPS Positions J Export Features That Have No Positions Cancel Default Help Figure B6 4 The position filter tab of the export setup dialog Coordinate System Tab The Coordinate System tab provides two alternative export options data can be exported based on the current display coordinate system or using an export coordinate system While no spatial element is being exported this coordinate system information should still be set as the parameters will control the system of the stated X and Y f
32. relevant tables within the database whenever the user moves to the next form Figure 2 5 At the end of the data entry process the GPS data is added to the database and the user is asked to add a further point move to the next PSU or exit the project At the same time the GPS information is added to the general information table Automated Geo referenced data entry for agricultural land use 118 Private Sub btnNext_Click ByVal sender As Object ByVal e As System EventArgs Handles btnNext Click Check to see if a Land cover value has been entered If finalLC1 Is Nothing Then MsgBox Please enter a primary land cover class Exit Sub End If If finalLC2 Is Nothing Then finalLC2 End If Save selected land cover information to database and move to next form Call opendatabase rs New InTheHand AdoceNet Recordset rs Open Land_Cover conn InTheHand AdoceNet LockType Optimistic Add data to fields rs AddNew rs Fields SAMPLEID Value psu amp ssu rs Fields LAND_COVER1 Value finalLC1 rs Fields LAND_COVER2 Value finalLC2 rs Fields LAND_COVER_NOTES Value txtLCNotes Text Update and close record Call updateandclose Timer1 Dispose shut True Open next form Dim openform As frmLandUse openform New frmLandUse openform Show openform Nothing Me Close End Sub Figure 2 5 Sample of code for adding the Land Cover reference to the database Through out the data e
33. sub areas to limit file size Prior to opening the survey location data file the shapefile must be converted into a Trimble file format using the tools available within TerraSync e Navigate to the Data section of TerraSync select Data from the Section list menu e Select File Manager from the Subsection menu e Select Read data from shape from the Options list menu to open the Read from Shape dialog e The Read from Shape dialog allows the shapefile to be converted into a TerraSync data file e Enter an appropriate name for the TerraSync data file in the Create data file input box e Using the From Shapefile s in drop down list menu navigate to the folder in which the survey location shapefile is stored The survey location shapefile should now be listed at the base of the dialog in the Include section e At the base of the dialog in the Include section ensure that the check box adjacent to the survey location shapefile is checked e Click OK A dialog will be shown which indicates that conversion is taking place Note once this conversion process has been undertaken the data file will be stored on the device therefore the conversion process need not be repeated at each survey location e Once the conversion process is complete dismiss the Conversion dialog To open the newly imported file or pre existing file e Navigate to the Data se
34. tado 74 POSITION DILUTION OF PRECISION PDOP ccccsssececsescecesssececseseececcsneeecsesaeeecseaeeeesseeecneaeeeeneeaees 74 BATTER STATUS ds 74 4 NAVIGATION AND BACKGROUND MAB cccscsssscscsssssssecccsessssceseccccesscsssscececcesssssssenecees 75 BACKGROUND MAPS AND DATASETS cocccccccccnccnnnononononononononononononononnnnnnnnnnnnnnnnnnnnononononononononnnnnnnncncnononoss 75 NAVIGATION EREE EE AEE OTERA a dio 80 S5 DATA COLLECTION ieisedissesscbsciecdctaceeese guess aneesscbisdecdessaseeacs c escessnsesbessateseessoasades ccdecsasdvsesacbscteacs 84 DATA FILE CREATION da cis 84 A A 85 DATA CUE TAN a cc 87 6 PROCESSING THE DATA sessssesdscsescecsnsctesssvscsesssveseesdsdneeses soscsessiccaesoesosuonsesccsesessesssosceedceessseeuoessaes 91 CONNECTING THE GPS UNIT TO THE PC oocnnnnnnnnnnnnnnncncnnnnononononononononononononononononononononononononononononinaneso 91 OPENING AN EXISTING PATHFINDER OFFICE PROJECT cccccccccccccccccscececccscscececscscecscsescsceceseceseceseveves 91 FTE TRANSFER 1 ycececeesos EE EEE ieee ape l eee a eee havo aaa ico 92 VIEWING THE RECORDED FEATURES ococcccccccnononononononononononononononononononononononononononononononononononononeneninenenes 92 DATA ER ia aid 93 APPENDIX C sossscesiscs iaceasds cseads sa chaeed destined cgtuasaecedssocscedecsssstacdessusseidedsesescuduoascvessdcvecodsessavuesecvescuscssescs 103 BESPOKE GPS APPLIGA TION ivssssssscsscscsavsscssseccosvesacvassoscosecvet
35. to reflect the default folder for this project By default the project name will be the same of the folder in which data generated by the project will be stored e Ensure that the Project Folder path is an acceptable storage location e The remaining Folder fields can remain on the default settings Automated Geo referenced data entry for agricultural land use 61 By default projects created within Pathfinder Office consist of a series of data folders automatically created by the software for use in different tasks Within the main project folder named according to the name specified for the project are three standard folders named base export and backup e Leave the remaining folder field names unchanged to accept the standard folder naming conventions e Accept the new project settings by clicking OK in the Project Folders dialog The settings you entered in the Projects Folders dialog should be reflected in the Select Project dialog e Click OK to close the Select Project dialog Additional Information If you have already created a project and wish to continue working in the same folder ensure that the existing project is selected in the project name drop down list at the top of the Select Project dialog Connecting the GPS unit to the PC The following tasks require the transfer of files between the PC Pathfinder software and the GPS unit therefore before continuing you must ensu
36. visibility from the location Automated Geo referenced data entry for agricultural land use 70 Points can be selected by clicking on a world map selecting a city from a predefined list or manual keyboard entry As the survey location coordinate is precisely known the following instructions illustrate keyboard entry for point creation e Click Keyboard in the Edit Point dialog For point definition a name latitude and longitude coordinates must be specified other data entry fields are optional e Enter an appropriate name in the Station Identification section of the dialog This may be for example the sample point identification number e Click inside the latitude input box Specify the latitude of the survey location ensuring that the coordinate is given in degrees minutes and seconds with each element being placed in the appropriate box e Specify whether the latitude coordinate is North N or South S using the radio button adjacent to the coordinate e Repeat for the longitude coordinate If further information about the survey location is known it can be entered into the remaining fields or they can be left as default empty values e Click OK to accept the changes and return to the Edit Point dialog e The coordinate and name information specified for the point should be listed in the Edit Point dialog e Click OK to create the point The Quick Plan utility automatically displays
37. with complicated program development hidden behind single click solutions Applications developed within the CyberTracker software are based on a series of data collection screens the design and sequence of which is user defined Multiple screen templates including lists check boxes and text input allow for the collection of data in various formats To ensure concise screen design data collection is based on a sequence of data collection screens which step through the predefined data collection tasks A major advantage of this approach is functionality to enable the screen sequence to be based on preceding data input The CyberTracker software contains functionality to enable the integration of field data collection with GPS location recording This data is recorded as a single point or track a series of points created as the surveyor moves A current limitation of GPS integration within the software is that GPS recording represents only a single point measurement An ideal solution would enable the recording of multiple positions averaged to provide a more accurate location estimate Once designed on the desktop PC the field data collection application is uploaded onto a mobile device Subsequent to data collection data is viewed in the desktop CyberTracker software from which export options are available to allow transfer of this data into standard GIS software The CyberTracker software suite is primarily designed for conservation a
38. 2 Technical document n 9 The estimation methods EUROSTAT LUCAS 2006 http forum europa eu int irc dsis landstat info data 2006_methodology htm Accessed December 2006 Person J 2004 Writing Your Own GPS Applications Part 1 Accessed 12 July 2006 http www programmersheaven com 2 Writing Your Own GPS Applications Remmezwaal A 1989 Classification of Land Cover and Land Use IstApproach FAO Rome 15 pp Taylor J Sannier C Delinc J Gallego F J 1997 Regional Crop Inventories in Europe Assisted by Remote Sensing 1988 1993 Synthesis Report EUR 17319 EN Office for Publications of the EC Luxembourg 71pp Trimble 2006 TerraSync Operations Guide USA Trimble Navigation Limited Whitten J L Bentley L D Dittman K C 2001 Systems Analysis and Design Methods 5h Edition New York McGraw Hill Irwin Young A 1998 Land resources Now and for the future Cambridge University Press Cambridge Automated Geo referenced data entry for agricultural land use 46 Appendix A Automated Geo referenced data entry for agricultural land use 47 Appendix A Land Cover and Land Use Survey Data Dictionary Definition Manual 1 Introduction This manual outlines the definition of a data dictionary for subsequent implementation in a GPS Global Positioning System survey Appendix B The manual will focus on the creation of dictionary within Pathfinder Office for subsequent implementa
39. 2002 2003 consist of a clustered sample and rely on a two stage sampling The initial stage defines the Primary Sample Units PSUs which can be assimilated to square or rectangular segments The second Automated Geo referenced data entry for agricultural land use 34 stage defines the Secondary Sample Units SSUs which normally consist of a grid of points within the PSU as shown in Figure 4 4 1 a Center of PSU wy 8b Cc lt 4 f o a o ens D h O 18km_ a Wa SS Figure 4 4 1 LUCAS 2002 2003 sample design Delinc 2001 As discussed by Delinc 2001 the use of a clustered sample presents a way of reducing the variance of the final estimate However another way to achieve the same goal is to undertake a stratification discussed in the next section This was the approach adopted as part of the new LUCAS methodology implemented from 2005 Instead of a clustered approach the sampling grid is based around the Lambert Equal Area coordinate system for Europe The LUCAS master sample is defined by the intersection of the grid every 2 km for even coordinates LUCAS 2006 The master sample is then combined with the country boundaries and a Digital Elevation Model DEM is used to exclude areas above 1200m elevation Each point is then photo interpreted in one of seven strata with the help of recent digital orthophotographs or if not available satellite imagery and the Corine Land Cover 2000 d
40. AO Rome 242 pp Farmer E 2005 An investigation into procedures to increase the versatility of land cover map production Landscape Ecology Remote Sensing and GIS Monitoring Ecosystem response to landscape change RGS IBG Annual Conference London 2nd September 2005 Farmer L 2006 Personal Communication Gallego F J 1995 Sampling Frames of Square Segments Official Publication of the European Communities EUR 16317 72 pp Gay C and Porchier J P 1998 Land Cover and Land Use Classification using TER UTI Agricultural Statistics 2000 Washington March 18 20 193 201 Global Land Cover 2000 database European Commission Joint Research Centre 2003 http www gem jrc it g1c2000 Automated Geo referenced data entry for agricultural land use 45 Jansen L J M 2005 Harmonisation of land use class sets to facilitate compatibility and comparability of data across space and time 11 CEReS International Symposium 13 14 December 2005 Chiba Japan Jansen L J M and Di Gregorio A 2003 Land use data collection using the Land cover Classification system Results from a case study in Kenya Land Use Policy 20 131 148 LANES 1997 Development of a Harmonized Framework for Multi Purpose land Cover Land Use Information Systems derived from Earth Observation Data European Commission CESD Communautaire Luxembourg LDCS 2006 http www planning org lbcs Accessed October 2006 LUCAS 200
41. Cranfield UNIVERSITY Feasibility study on automated geo referenced data entry of agricultural land use Christophe A D Sannier Tim R Brewer Elizabeth A Farmer School of Applied Sciences Cranfield University Cranfield Bedfordshire MK43 OAL United Kingdom e mail christophe sannier sirs fr com t brewer cranfield ac uk Automated Geo referenced data entry for agricultural land use 1 Ti INTRODUCTION besscssssesessccsvscesaceosedeceatecaesssesecsececvaysesassacueseceassatessesnesassecesbacvacesbocbabestasdenessecvas ees 5 2 CLASSIFICA TION SCHEM Eivsccscccccissteocdsescdsvsesssesuctbessenstesseenseesestuceussestdssudoevcbsbvace coessdessusdecsesss 6 2 1 BACKGROUND Sees E a antes Se ees 6 2 2 LAND USE CLASSIFICATION cccccccccsecesecssecssessseessesssesssesssesscesscessceaecesecsescaeecsssesssessessseesaserees 7 221 BACKS LOU 2 seins cas e aaa 7 2 2 2 Proposed classification approach oooocccnnconnnnnonnnannonnnanonnnnnnn cono cnno cnc conc on nora nono nn nn rnnnrnnan 8 2 2 3 Demonstration data dictionary sccccccccssecesncceesseceseceessecesecesceceeneeeaseceeeeesaceceeeeceeaeecsaeeesaes 8 3 CLASSIFICATION IMPLEMENTATION WITHIN A GPS DEVICE Q scccsssscsessseeees 23 3 1 INTRODUETION at tdt tt e T 23 3 2 DATA DICTIONARY BACKGROUND ccccccscccessceescecesceessecesscecssecesscecsseceasseessecesseesssecsteeessees 23 3 3 DATA DICTIONARY DEVELOPMENT FOR LAND USE AND LCCS CHARACTERISATION
42. Non graminoids Simulltaneous Overlapping Sequential TIT D Cultural Practices Water Supply Rainfed Post flooding Irrigated Surface Irrigation Sprinkler Irrigation Drip Irrigation Cl C2 C3 C5 C6 C7 C8 C17 C18 C19 C13 C14 C15 C16 C17 C18 C19 D1 D2 D3 D4 D5 D6 D Cult Practices Cult Time Factor Shifting Cultivcation Fallow System Permanent Cultivation S Crop Type Food Crops Cereals amp Pseudocereals Roots amp Tubers Pulses amp Vegetables Fruit amp Nuts Fodder Crops Beverages amp Stimulants Other Non Food Crops Industrial Crops Wood Timber Other D7 D8 D9 S1 S3 S4 S5 S6 S7 S8 S13 S2 S9 S10 S14 Automated Geo referenced data entry for agricultural land use 16 Land Cover Classification System Code A12 Nat amp Semi Nat Terrestrial Veg I A Life Form of the Main Strata Woody Al Trees A3 Shrubs A4 Herbaceous A2 Forbs A5 Graminoids A6 Lichens Mosses A7 Lichens A7 Mosses A9 A Cover Closed gt 70 60 A10 Open 70 60 20 10 A11 70 60 40 A12 40 20 10 A13 Closed to Open 100 15 A20 100 40 A21 Sparse 20 10 1 A14 lt 20 10 4 A15 Scattered 4 1 A16 B Height 7 2 m for Woody B1 gt 30 3 m for Trees B2 gt 14m B5 14 7 m B6 7 3 B7 5 0 3 m B3 5 0 5 m B14 5 2m B8 2 0 5 m B9 lt 0 5 m B10 3 0 03 m 3 0 3 m 3 0 8 m 0 8 0 3 m 0 3 0 03 m C Spatial Distribution Macropattern Continuous
43. Pathfinder Office software e Click the button labelled Devices to open the Devices dialog e At the base of the Devices dialog click New e In the Create New Device window select GIS Datalogger on Windows CE from the list of available devices e Click OK to close the Create New Device dialog e The GIS Datalogger on Windows CE should now be listed in the Devices dialog Click Close to close this dialog and return to the Data Transfer dialog On returning to the Data Transfer dialog the GIS Datalogger on Windows CE should be listed in the Device dropdown menu and the dialog should now be active If Pathfinder Office has been able to connect to the GeoXT the dialog will show that the device is connected Figure B2 3 If connection has not been successful the user may have to search again for the device by clicking on the Connect button Automated Geo referenced data entry for agricultural land use 65 LITT idx Device i 9 GIS Datalogger on Windows CE D 0 Bol Devices g a Connected to GIS Datalogger on Receive Send Windows CE p Files to Receive Li ioi Device Fei ais Datalogger on Windows CE y D 0 DO Devices as a Not Connected Receive Send Pane Disconnect E to Receive Add y Figure B2 3 Illustration of the Data transfer dialog after successful top image
44. S Position Info is selected e Ensure that the satellite parameters are set to minimum values to allow the export of all features o Minimum Satellites 2D 3 or more SVs o Maximum PDOP Any o Maximum HDOP Any e As no real time or post processing correction has been applied to the data all positions including uncorrected must be exported Check the Uncorrected option in the Include positions that are section The Position Filter tab should appear the same as Figure B6 4 Coordinate System Tab The Coordinate System tab provides two alternative export options data can be exported based on the current display coordinate system or using an export coordinate system If the current display coordinate system set within the main Pathfinder Office window is appropriate then the following instructions can be disregarded Alternatively an export system must be set e If the current display coordinate system is not appropriate select the Use export coordinate system radio button e Click on the button labelled Change to open the Coordinate Selector dialog Using the drop down menus within the Coordinate Selector dialog an appropriate coordinate system can be set for example in the case of latitude and longitude e Specify Latitude Longitude as the system using the drop down menu Automated Geo referenced data entry for agricultural land use 100 e Specify WGS 1984 as the datum
45. S data collection time for the LCCS feature the minimum number of GPS positions are reduced from 120 to 30 Data output from this multi feature approach will separate the land use and cover data for each sample point however it is anticipated that simple GIS techniques can be used to merge the data if required ii LCCS To enable LCCS characterisation more complex feature definition is required as the attributes recorded are dependent on previous stages in the classification hierarchy Within the data dictionary this parameter variability can only be removed via the explicit definition of several features These features must be defined to maximise feature variability so as to minimise within feature attribute variability and avoid drop down menus that are overly long In terms of LCCS this is achieved by defining feature types based on the third dichotomous phase of the hierarchy Automated Geo referenced data entry for agricultural land use 25 Using the third dichotomous phase the resultant data dictionary point features are gt Cultivated and Managed Terrestrial Area s gt Natural and Semi Natural Terrestrial Vegetation gt Cultivated Aquatic or Regularly Flooded Area s Natural and Semi Natural Aquatic or Regularly Flooded Vegetation Artificial Surfaces and Associated Area s Bare Area s Artificial Water Bodies Snow and Ice gt Natural Water Bodies Snow and Ice Greyed items are not available in the current demonstration data dic
46. Sierra Leone Automated Geo referenced data entry for agricultural land use 127 Appendix D2 Primary Sample Units for the implementation of the LUCAS 2003 methodology 50 Kilometers Legend C Background Ooo Deciduous woodland BA Closed evergreen lowland forest Deciduous shrubland with sparse trees Degraded evergreen lowland forest E Closed grassland N Oo Submontane forest O o Irrigated cropland Ooo Mangrove li Waterbodies W E a Mosaic Forest Croplands ua Cities 4 Sierra Leone NW LUCAS 2003 PSUs Automated Geo referenced data entry for agricultural land use 128 The estimation 1 of the area for a given land use land cover category based on the sample above is as follows adapted from LUCAS 2002 A WU 1 Res el 1 a dd where estimated area of the land use land cover in the considered geographic region A area of the considered geographic region m number of PSU in the considered geographic region yij 0 0 5 or 1 the amount of land use land cover in the SSU j within the PSU nj number of SSU within the PSU i The internal and external variance of PSU may be calculated and the total variance 2 is the sum of those A M m 1 12 2 eo im x M o E yat Pr where valga lu ua pA hi n 2d hi hi 1 and where then A area of the considered geographic region m number of PSU in the considered geographic region n number of SSU in the considered geographic region yj 0
47. T_531 Mixed Grain CT_103 Soybeans CT_236 Cherries Sour CT_530 Mushrooms CT_449 Spices nes CT_723 Chick Peas CT_191 Mustard Seed CT_292 Spinach CT_373 Chillies and Peppers Green CT_401 Natural Gums CT_839 Stone Fruit nes Fresh CT_541 Citrus Fruit nes CT_512 Natural Rubber CT_836 String Beans CT_423 Cocoa Beans CT_661 Nutmeg Mace Cardamons CT_702 Sugar Cane CT_156 Coconuts CT_249 Nuts nes CT_234 Sugar Crops nes CT_161 Coffee Green CT_656 Oil Palm Fruit CT_254 Sweet Potatoes CT_122 Cow Peas Dry CT_195 Oilseeds nes CT_339 Tangerines Mandarines Clementines Satsumas CT_495 Cucumbers and Gherkins CT_397 Okra CT_430 Taro Coco Yam CT_136 Eggplants CT_399 Olives CT_260 Tea CT_667 Fibre Crops nes CT_821 Onions and Shallots Green CT_402 Tobacco Leaves CT_826 Flax Fibre and Tow CT_773 Onions Dry CT_403 Tomatoes CT_388 Fonio CT_94 Oranges CT_490 Vegetables Fresh nes CT_463 Fruit Tropical Fresh nes CT_603 Papayas CT_600 Watermelons CT_567 Automated Geo referenced data entry for agricultural land use 11 Garlic CT_406 Peaches and Nectarines CT_534 Yams CT_137 Ginger CT_720 Pears CT_521 Yautia Cocoyam CT_135 Gooseberries CT_549 Peas Dry CT_187 Other CT_999 Automated Geo referenced data entry for agricultural land use 12 Agricultural LU Characterisation CROPS Crop Systems Bush fallow shifting cultivation Multiple cropping Crop rotation Improved cultivars Agro forestry Controlled environment greenhouse Pest weeds
48. a or classifiers Class boundaries are determined by either the presence of one or more distinctive criteria or the number of criteria used This takes the emphasis away from the class name and focuses on the mix of criteria The advantage of this approach is that it removes much of the subjectivity often associated with a user applying class names and descriptions to land cover classification The classification is hierarchical and has two main phases the Dichotomous Phase and the Modular Hierarchical Phase The initial phase is used to identify eight main land cover classes FAO 2005 Cultivated and Managed Terrestrial Areas Natural and Semi Natural Terrestrial Vegetation Cultivated Aquatic or Regularly Flooded Areas Natural and Semi Natural Aquatic or Regularly Flooded Vegetation Artificial Surfaces and Associated Areas Bare Areas Artificial Water Bodies Snow and Ice e Natural Water Bodies Snow and Ice Three diagnostic criteria are used to define these classes presence of vegetation edaphic condition and artificiality of cover FAO 2005 The Modular Hierarchical Phase creates more precise land cover classes through combinations of sets of pure land cover classifiers The set of classifiers used for each main land cover class is different Information from the classifiers can be augmented Automated Geo referenced data entry for agricultural land use 6 by reference to further attributes of the land cover These could
49. aSync with a target set Trimble 2006 The main element of this window when navigating to a target is the direction dial which is located centrally in the window This dial indicates the surveyors current direction of travel heading relative to the target location Therefore to reach the target location using the shortest path the surveyor should align the arrow direction to target with the current direction the triangle at the top of the dial When using this navigation dialog there are two important elements which should be considered Firstly to calculate an accurate current heading and therefore required travel direction the GPS unit must be moving If the surveyor is moving too slowly or stationary the heading arrow will appear to freeze Secondly the arrow indicates the shortest route to the target location this may not be the safest or most appropriate path Automated Geo referenced data entry for agricultural land use 80 in terms of land use and land ownership therefore detours away from this suggested route may be required In addition to the navigation dial the navigation section of TerraSync is supplemented with a series of information fields which provide further details on the current heading distance to target etc These information fields can be replaced by a series of information fields using the drop down option at the side of any current field When the surveyor approaches a specified distance from the targe
50. ach classifier Data recorded is downloaded for subsequent analysis within suitable software packages for example the LCCS program GIS software or databases 3 2 Data dictionary background A Trimble data dictionary contains a description of features and their attributes relevant to a particular data collection task A data dictionary can therefore be considered a template for data collection This template provides the outline for data collection tasks but does not store either the positional or the spatial attribute data of features which are stored in the Trimble rover file The data dictionary can be considered as being constructed from two elements the features to be collected in the field and secondly a list of attributes which describe each of these features Automated Geo referenced data entry for agricultural land use 23 Features Features recorded via a data dictionary can be described using either a point line or polygon data structure Feature descriptions can be edited to meet the project requirements and multiple features of the same type are permitted within a single dictionary definition Feature Attributes Attributes are feature specific and take the form of a series of data fields which accompany the standard GPS positional information Fields can be designed to contain numeric or text data entries In addition data integrity can be ensured with the implementation of drop down selection and required fields durin
51. ad to data loss The export process requires the setting of a series of parameters which govern the output data type and the characteristics of the output file Specific parameters are file type specific however common parameters include gt The output file type and location gt The operating system the files are intended for Automated Geo referenced data entry for agricultural land use 93 The spatial coordinate system of the output features or their positional data The units of any GPS derived information i e length and area Any additional attributes derived from the GPS referred to as generated attributes such as PDOP and precision VV V Tabular Format One alternative is to export the Trimble data file to a table held in a dBase format dbf In this case the spatial information will be held in the form of two X Y coordinates within the table e In the Input Files section of the dialog ensure that the imported data file is listed in the selected file list If the file is not listed click on the Browse button in the Open dialog navigate to and open the appropriate Trimble data file e Ensure that the output folder is an appropriate location By default this will be the export folder contained within the project folder e Using the drop down menu set the Export Setup to Sample dBASE Setup Figure B6 1 e Click the button labelled Properties at the base of the dialog to open the Setu
52. aeme Gould 001 22 0 437402630654762W 52 0040503011905N 3 07 08 2006 03 41 52 PM 00123 gg06 Graeme Gould 001 23 0 434893765060241W 52 0030557849398N 3 07 08 2006 03 37 53 PM 00124 gg06 Graeme Gould 001 24 0 429379491102757W 52 0028738422306N 3 07 08 2006 03 28 37 PM 00125 gg06 Graeme Gould 001 25 0 424914728021978W 52 0028789254579N 2 07 08 2006 03 19 08 PM Table 3 2 Land Cover database table SAMPLEI LAND_ D 00111 00112 B11 00113 B53 00114 All 00115 A22 00121 C21 00122 B11 00123 B53 00124 E01 00125 F00 C21 COVER LAND_COVER2 LAND_COVER_NOTES C21 The codes stored in the land cover and use tables can be referenced back to the classification databases to provide the descriptions for the identified land classes photograph to be linked to a sample point The codes stored in the photograph reference table allow the The comparison of positions recorded by the field data application and TerraSync shows very little difference Table 3 3 in most instances it is less than 50cm Table 3 3 Positional differences between the new application and TerraSync TerraSync Field Data Collection ID Longitude Latitude Longitude Latitude Difference m 11 0 427898799 52 005121909 0 427900548 52 005121828 0 120 12 0 427898264 52 005121165 0 427900935 52 005121798 0 196 Automated Geo referenced data entry for agricultural land use 122
53. and hence the surveyor need not consider these parameters in the field More details on these parameters is available in the data dictionary portion of the manual Automated Geo referenced data entry for agricultural land use 85 GPS parameters are set after data file creation to ensure that the parameters are stored within the file As a result GPS parameters are file specific However when a file is re opened the originally specified parameters will be preset Logging Settings Many of the logging settings are pre defined in the data dictionary hence only one parameter will be considered here e With the data file still open move to the Setup section of TerraSync select Setup on the section list menu e Click on the button labelled Logging Settings e Ensure that the drop down menu labelled Confirm End Feature is set to Yes Figure B5 2 Confirm End Feature Filename Prefix AA Figure B5 2 Confirm end feature logging settings e Leave all other menu items at the default value e Click OK to exit the logging settings Real time Settings e Ensure you are still in the Setup section of TerraSync e Click on the button labelled Real time Settings e Ensure that Use uncorrected GPS is selected in the Choice 1 drop down menu e Click OK to accept the changes and return to the Setup section GPS Settings As stated previously PDOP is a measure of the
54. ap display WGS 84 set in the previous step a warning message will be displayed and the raster not added to the map window To resolve this issue check the projection definition in the Setup section If the coordinate systems match on returning to the map view in addition to your current GPS location the raster image should also be visible If the background image is not visible ensure that the layer visibility is enabled The background layer is visible if the Background option is checked within the Layers list menu Figure B4 3 By checking and un checking this option the background layer visibility can be toggled between visible and hidden Between Feature GPS v Background v GPS Trail Background File Layer Formatting Figure B4 3 Background layer visibility Loading background vector layers e From the Section list menu select Map e From the Layers list menu click Background File The map will be replaced with the background file selection dialog Figure B4 2 e Ensure the Location drop down list menu is set to Device e Set the File Type to Data File using the drop down list The available data file s stored on the device should now be listed in the files section at the base of the dialog e Highlight the appropriate imported vector file s e Click OK to return to the map display view On returning to the map view in addition to your c
55. appropriate Trimble data file e Ensure that the output folder is an appropriate location By default this will be the export folder contained within the project folder e Using the drop down menu set the Export Setup to Sample ESRI Shapefile Setup e Click the button labelled Properties at the base of the dialog to open the Setup Properties dialog The Setup Properties dialog contains all the parameters for the current export setup Changing these parameters will influence the characteristics of the output shapefile For the current export only a small number of parameters need be changed from their default values Automated Geo referenced data entry for agricultural land use 98 Data Tab e Click the Data tab at the top of the dialog e In the Data tab ensure that the Type of data to export is set to Features Positions and Attributes using the radio button and that the drop down menu is set to Export All Features Output Tab e Click the Output tab at the top of the dialog e Ensure the output files is set to Combine all input files and output to the project export folder Attributes Tab e Click the Attributes tab at the top of the dialog The Attributes tab contains options regarding the generated and feature attributes Setting these parameters will influence the fields and data contained in the exported dBase table e At the top of the dialog
56. ata collection and GPS interaction between the unit and GPS satellites to be specified Automated Geo referenced data entry for agricultural land use 59 Sections and Subsections Several of the TerraSync sections outlined in the previous discussion have a series of subsection elements These subsections are section dependent and allow further control of the TerraSync software Subsections are selected using the secondary drop down typically found in the top left of the TerraSync window Figure B1 2 Subsection list button aS29 SD STIN 172 3354 14YE 35 1 le AE POOP 3 35 Heading Locked Produchuity Preceton Ot es 0 Figure B1 2 Identification of the subsection list button and drop down menu Trimble 2006 If the current section being viewed has subsections then the subsection list button will automatically be available Moving between subsections is possible at anytime although some subsections may be unavailable depending on the current task Automated Geo referenced data entry for agricultural land use 60 2 Preparing for data collection Prior to data collection the Pathfinder Office software will be used to transfer the land cover land use data dictionary and raster background maps to the GPS unit Pathfinder Office is the PC based software that accompanies Trimble GPS units needs to be purchased separately This software provides tools which enable user to plan GPS surveys and successfully download and process t
57. ata dictionary has been constructed to ensure that at least 120 GPS positions are recorded at each survey location These positions will be recorded at a 1 second interval whenever logging is viable If GPS logging is interrupted due to GPS signal loss or PDOP values exceeding the stated maximum the logging status symbol will cease incrementing An additional indicator that logging has stopped is a drop in the number of satellites being tracked this may be accompanied by an error message or a PDOP warning message Collecting attribute data At each survey location the GPS positional data is accompanied by a series of attribute data fields These attributes will vary according to the feature type selected The attribute data fields for the current feature are displayed within the logging position form These attribute fields are represented by a series of drop down menus from which the most appropriate classifier can be selected In addition to the attribute drop down menus a single numeric field exists for each feature The unique survey location identification number should be entered in this field e Using the drop down menus and numeric keyboard select an value for each of the attribute fields Pausing GPS logging If necessary it is possible to temporarily pause the logging of GPS positional data while at a survey location using the following steps Automated Geo referenced data entry for agricultural land use 88 e Click the button
58. ata set CLC2000 Each stratum is sampled at a different sampling rate to maximise the efficiency of the stratification see table 4 4 1 The rationale for selecting the different sampling rates is primarily based around the land cover use types that are more critical to characterise 1 e agricultural land cover use types in this case thus resulting in more precise estimates for agricultural land use cover types whilst maintaining costs to a reasonable level A secondary reason is that it tends to put less emphasis on land cover use types that are less likely to change over time It has been shown that the new approach brings an overall reduction of the variance by a factor of three and avoids the problem of incomplete PSUs LUCAS 2006 Moreover Farmer 2005 demonstrated that there was no significant increase in the survey time with a one stage systematic sample compared with a 2 stage clustered approach This was confirmed with the initial trials of the new LUCAS methodology which appear to suggest that survey costs will be less than with the 2 stage approach LUCAS 2006 Automated Geo referenced data entry for agricultural land use 35 Table 4 4 1 Sampling rates applied by stratum LUCAS 2006 The sample is drawn by grouping sample points on a 9 by 9 basis thus resulting in blocks of 81 points Each replicate is selected randomly ensuring that successive replicates are not next to one another and its position repeated across the grid
59. ation systems are to be used and clicks create project The project name is validated the project database is created and a confirmation of the new project being created is displayed and returns the surveyor to the main page Exceptional flow of events If the surveyor enters a project name that already exists a prompt is raised requesting them to enter a new project name Automated Geo referenced data entry for agricultural land use 104 Exceptional flow of events If the surveyor clicks select land cover classification the system displays the select classification screen Exceptional flow of events if the surveyor clicks select land use classification the system displays the select classification screen Exceptional flow of events If the surveyor clicks the cancel button the create new project window is cancelled and the surveyor returned to the main menu page e Open Existing Project Main flow of events The surveyor selects the Open Existing Project button that displays the open project form The surveyor selects the project to open and clicks the open project button The surveyor is taken to the first data entry page Exceptional flow of events If the surveyor clicks the cancel button the open project page is cancelled and the surveyor is returned to the main page Exceptional flow of events If no projects are found a prompt is raised indicating that a project needs to be created first and opens the create new project page
60. averaged to produce a more accurate position Throughout the data collection period the PDOP is monitored and if it falls below a specified level GPS data collection is suspended and the user notified Error handling and error checking is present throughout the interface coding so that the risk of the application falling over is reduced Checks are made as to whether there is data on the port and whether it is the correct data Monitoring the precision so that it doesn t get too high is a further error handler Automated Geo referenced data entry for agricultural land use 117 2 4 3 The Database application The core of the application is that of a database management system The application creates and updates a project database with land survey information The ADOCE tool is used to provide database support This tool needs to be installed on the mobile device to enable it to operate The surveyor is provided with two main options when starting the application The create project database option generates an empty database with a name selected by the surveyor The database is created with six empty fields Figure 1 5 The surveyor also identifies at this stage the two classification systems that will be used The open project option allows the surveyor to open a project and add data Data entry is achieved through a sequence of data entry forms that lead the surveyor through each requirement of the LUCAS methodology Data is added to the
61. ber of programming languages that can be used and selection of the correct language is essential The primary requirement of the language is that it can be used to create programs for installation on a mobile CE device Farmer 2006 has shown that Microsoft Visual Basic NET VB NET is suitable for this task and will be used for the development of the field data application VB NET is an object orientated programming language that comes as part of the Visual Studio NET group of products It is designed for programming in the Windows and Web environments Cowell 2002 VB NET is part of Microsoft Visual Studio 2003 which has been used with the addition of some add ons to develop the application A newer version of Visual Studio exists but is not available for this project 2 3 Additional Requirements Databases are not supported in this version of VB NET To enable database creation and communication ADOCE 3 1 from In the Hand is required This allows creation of Compact Databases cdb which when transferred to a desktop PC are converted by Microsoft ActiveSync into Microsoft Access databases The GPS interface links to the GPS receiver through a specified COM port Visual Studio 2003 does not support communication with the COM ports To Automated Geo referenced data entry for agricultural land use 113 2 4 overcome this SerialTools is installed which provides this support SerialTools is available from Franson www franson com a
62. c0 c00sc008s 25 3 3 BESPOKE APPLICATION DEVELOPMENT ccccccescccsssceesceceseecssecesssecssecesseecseecesseesseecssseeeseees 29 4 SAMPLING STRATEGY siscssssvcstesscudsescetssetscscccsesscsvsuvescevsesecssuseniesevchessesvectessunsesssudeessssaecccesesses 31 4 1 BACKGROUND ooo E E A E EE E S EEEE EEEE EEA 31 4 2 SEGMENT WITH IDENTIFIABLE BOUNDARIES 0 cseccesssecsscceescecssecesseecsccesseecesscessesenssenseees 31 4 3 SQUARE SEGMENTS 3732 as 33 4 4 POINT SAMPLE munninn noaten e dis iia 34 4 5 STRATIFICATION 4 a a el cated tases AE asi 36 4 6 RECOMMENDATIONS 23 03 00 Ree eee BEE ee ee Sn a id 37 5 FIELD DATA COLLECTION SYSTEM sccccsssssscsssssccsssscccsssssccssssssessssccscssseccssssscesessnee 38 5 1 GPSCONCEPTS 2 ds ts do e e a a 38 5 2 LOW COST HANDHELD EPS ta 39 5 3 PDA Sada 40 5 4 MAPPING GP O e dd 41 5 5 RECOMMENDATION Sia 43 PACK ARG J oirrne Ee a E crasas ta aid 43 PACK ABO Li na ainda csi 43 Packard rinde 43 Packard eo daub EE EEEa eS E EN neea 43 6 ANAIS 44 NN D E o E S NO 45 APPENDIX A DATA DICTIONARY DEVELOPMENT ccssssssssscssssssscrsccccscscsscececcsesesssscees 48 LAIN TRODUG TION wiv cissvseccssnsstucestvsce losscesedaveceesseussssusess3esusesesasweastv uvssdesuecesssestdh beseedeesvseesssbectudeussese 48 SOFTWARE AND HARDWARE REQUIREMENTS scsssccecsesessscesecececsesaaececececsensaaeceecceceensaasaeeeeeeeenenseaeees 48 2 PATHFINDER OBR FIG Bisissesetissecis Gasiec
63. ccesecicacsceuedacedies ihsuc terete A eaa eae dewe a 123 4 FUTURE DEVELOPMENTS sssesssoseessoceessecesssecsscoecssoceesseceessecsscoeessoceesseceessecsssscessoseesseoeese 124 4 1 INTRODUCTION a a sbeebs 124 4 2 CEASSIFICATION SYSTEMS E E E E E E E EE 124 4 3 SURVEY METHOD Y A O E E r ves e AER 124 4 4 AY A RITAN EA RE EA EN D E E E E E E Ee EES 125 APPENDIX D SIERRA LEONE EXAMPLE AND STATISTICAL FORMULAEG 0008 128 Automated Geo referenced data entry for agricultural land use 4 1 Introduction Land use concerns the activities undertaken on the land in order to obtain benefits from it However certain land use activities could have undesirable effects e g land degradation Knowledge of land use practices is therefore crucial for defining various interventions e g policies investment strategies choice of sustainable technologies etc that would lead to desirable modifications in how land is managed in order to better meet societal needs In particular land use information is needed by countries in order implement action programs related to the achievement of the Millennium Development Goals 1 and 7 and a range of activities within the framework of various global environmental conventions such as the United Nations Convention to Combat Desertification UNCCD and the United Nations Framework Convention on Climate Change UNFCC Despite its importance very little global to regional land use information based
64. ced data entry for agricultural land use 108 Enter Name Create Project Database Initialise Database Surveyor Y Database Structure Project Database Sample Point Data Selecte Open Project Update and Database close project Sample point data Sample Paint Data Add Sample Information Selected Classification Systems GPS Coordinates and Precision Land eG Dlassification Get GPS Coordinates Land Use _p Classes Land Cover Classification Land Cover Classes Position Sentences GPS Figure 1 3 Summary Data Flow Diagram The purpose of the GPS interface is to provide the link between the GPS receiver and the application and to extract the required information from the GPS data The interface consists of a number of processes Figure 1 4 that provide the required functionality Within the GPS interface process shown in Figure 1 3 there are a subset of processes which are the building blocks of the process A further level beyond that in Figure 1 4 is not necessary as it would consist of actual code Automated Geo referenced data entry for agricultural land use 109 Select COM Port Surveyor Select COM port Available COM GPS nmea COM Port List COM ports Y Port list Start GPS Receiver Enable receiver GPS Sentence GPS Read GPS Receiver Data E
65. chalet as 8 Lees 59 IO Y E A AS RA 59 A E E RO 59 SECTIONS AND SUBSECTIONS ccccsscesesesesesesesesesesesecesesesesesesesesesesesecesesesesesecerereceseeeseseceseceseseseresens 60 2 PREPARING FOR DATA COLLECTION cccssssssssscsssscsseccccccsssssssececcccsssssscececccsssssssececees 61 CREATING A PATHFINDER PROJECT ccccccccccccccscscecccccscscscsesesesesesescsesesesesesesesescscecscsssceeseesesesesesesesesenscs 61 FO CREATE AsNEW PROJECT ai a ela 61 CONNECTING THE GPS UNIT TO THE PC oonnnnnnnnnnonononinononinnnnnononnnnnononnnnnnnnnnnnnnnonononononononononininininininss 62 Jii D E DESENNIA E E EE E E E E E atu eo Leta see A SEN aoa ee IR 62 THE LAND COVER AND LAND USE DATA DICTIONARY oococccccccnccncnncnononononononononononononnnnnnnnnonononononinininanoss 63 BACKGROUND MAPS 33 ccs feuee cite E EE ATA E E E E iment abate Nea ees 63 DA TAcTRANSEER ico o8s c0c05 vou Soee sacs Guage E A ta 65 SURVEY POINT LOCATIONS 55s sise5e ocwbeveeshiveeu sieves shasu ies new bovee Maw elev osu bevasataseles peubovasadevedeuitunecesatasevevaes 67 PROJECT aa AININ INE AEE E A EE A uu eae Re oes 68 QUICK PLANNING usais 70 3 GPS SETUP AND INITIAL TASKS 8iscvesssssstsscisndusscssssiesssseceossuvecessesccte sesevesssuscceossessssstsessestuscsesesys 73 NS A teks vet E EEEE E E leas se od i as ited ic as i del eae le 73 OPENING TERRAS YNG E AAE E EEEE EEEE EEA ek sce Bees Cv ober cabot EE E E 73 CHECKING THE GPS AS aio 73 SATELLITE LOCATIONS 0
66. collection task In essence a data dictionary is a template for data collection This template provides the outline for data collection tasks but does not store either the positional or attribute data of features Data dictionaries therefore provide a means of structuring data collection tasks according to the required features of a survey and ensuring data integrity by limiting data input Background maps Background maps will be displayed in the map section of the TerraSync software to aid navigation and field interpretation These maps may be in a raster or vector format examples include aerial photography or satellite imagery of the area or vector format examples include ESRI shapefile data containing river or road networks Prior to transfer format conversion and processing of these data may be required Raster data Raster data should be stored in either a bitmap bmp JPEG jpg MrSID sid or TIFF tif format To enable these raster data to be displayed in the correct geographical location within the map section they should be accompanied by a world wld file which tells TerraSync how the pixels sit and relate to each other in geographical space and a coordinate system file This georeferencing information is easily created in a standard GIS package Vector data Supported vector file formats are AutoCAD DXF ESRI Shapefile shp and MapInfo mif To be displayed correctly the vector data should be georeferenced An
67. create a radio link between the field unit and base station However because of the extra processing required this would only be possible with code phase units and limited to metre level accuracy 5 5 Recommendations To meet the requirements of a land use survey as defined in the previous sections a mapping GPS device running Windows CE would be recommended If higher positional accuracy was required with the use of post processing differential correction the configurations below for packages 1 2 and 3 package 4 is excluded as standard GPS units are not capable of storing detailed GPS data can still be considered with the acquisition of an extra unit to be used as a base station Package 1 e Trimble Geo XM e Trimble Terrasync Professional software e Trimble Pathfinder Office software This unit provides a large amount of memory and can be easily configured to meet the requirements of the land use survey but the total cost is likely to exceed US 5 000 Package 2 An alternative is e Thales Magellan MobileMapper CE e ArcPad software It has similar characteristics the Trimble unit but does not have as much memory and would cost less at around US 3500 Package 3 The MobileMapper unit at around US 2000 is another realistic alternative but would not offer the capability to display satellite images as an image backdrop only vector data can be displayed Package 4 Finally simple handheld GPS could be used as a backup l
68. ction of TerraSync select Data from the section list menu Automated Geo referenced data entry for agricultural land use 79 e Select Existing File from the Subsection menu e In the existing file list using the scroll bars if necessary locate the TerraSync data file you just created containing the survey locations Select this file using a single tap or click e Click Open The survey location data file is now open TerraSync will automatically move to the Update feature form During the survey you do not wish to update these features as they will be used solely for navigation therefore you should navigate away from the Data section of TerraSync e Navigate to the Map section of TerraSync select Map from the Section list menu The survey point locations should now be visible within the map composition Navigation Navigating to the survey location will involve both the map and navigation sections of the TerraSync software Navigation targets the survey point will be set within the map section while the navigation section will inform the surveyor of the shortest path to the target location The Navigation section of TerraSync By default the navigation section of TerraSync when a target is set will appear as shown in Figure B4 4 Current direction Heading Direction of target Turn Message line Information fields Figure B4 4 The navigation section of Terr
69. d to transfer data files to the device this project will be used for almanac transfer e On opening Pathfinder Office the Select Project window will open by default If 1t does not open then select File Projects In this dialog you can open an existing project if a suitable project for your current work has been created or create a new project In this case the project created prior to field survey will be re opened e In the Select Project window ensure that the name of the project you created prior to field survey is selected in the project name drop down list e Click OK to close the Select Project dialog Automated Geo referenced data entry for agricultural land use 69 To download the almanac from the GPS device e Ensure a USB connection is established between the GPS and desktop PC using ActiveSync e In Pathfinder Office open the data transfer utility from the main menu Utilities Data transfer or by using the shortcut on the Utilities toolbar Es In the Data Transfer dialog ensure GIS Datalogger on Windows CE is the listed device within the Device dropdown menu If Pathfinder Office has been able to connect to the GeoXT the dialog will show that the device is connected Figure B2 3 If connection has not been successful the user may have to search again for the device by clicking on the Connect button If a successful connection cannot be established after re clicking the connection
70. data entry for agricultural land use 132
71. ded data instead of a text description For example the alphanumeric code of Al in the life form main crop field of a cultivated or managed feature is indicative of broadleaved trees The base of the dialog contains a series of generated attributes which can be derived by the software from the GPS data These generated attributes are grouped according to feature specific categories e From the All Feature Types group of the generated attributes section select PDOP by checking the appropriate check box As a result an additional field will be added to the dBase table which contains the average PDOP value for each feature e From the Point Features group of the generated attributes section select Horizontal precision The generated field values give an estimate of the horizontal precision of the averaged position for each feature This field is a distance measure the units of which will be set in the Units tab The line feature and area feature groups can be disregarded as neither of these feature types are relevant to the survey The Attributes tab should appear similar to Figure B6 2 Export Setup Properties Sample dBASE Setup xj Data Output Attributes Units Position Filter Coordinate System dBASE r Export Menu Attributes As Attribute Value Code Value 1 C Code Value 2 C Code Values 1 2 m Generated Attributes All Feature Types Point Features Height Ver
72. dies support the concept of using classifiers for land use classification The classification contained within the demonstration data dictionary given below incorporates land use classification derived from Young 1998 land use characterisation and the LCCS FAO 2005 and adopts the principle of using classifiers 2 2 3 Demonstration data dictionary Table 2 1 presents a demonstration data dictionary that can be incorporated within a GPS The LCCS component of the data dictionary only includes three of the tertiary level dichotomous phases These are considered to account for the majority of land Automated Geo referenced data entry for agricultural land use 8 cover types found within agricultural areas The remaining phases at this level from the LCCS classification can be added to the data dictionary if required Automated Geo referenced data entry for agricultural land use 9 Table 2 1 Demonstration data dictionary Site Identification Number required Survey Time Automatic Survey Date Automatic Simplified LU classification Conservation Total Partial Collection Plant products Animal products Forestry Management Natural forests Forest plantations Livestock production Extensive grazing Intensive grazing Confined livestock production N A N A N A LUCONI1 LUCON2 LUCOL1 LUCOL2 LUFOR1 LUFOR2 LULIV1 LULIV2 LULIV3 Crop production Shifting cultivation Temporary cultivat
73. e From the Datum drop down menu specify WGS 1984 e Set the Altitude Reference to Mean Sea Level MSL and Altitude units to Meters using the appropriate drop down menus The remaining fields Geoid model Geoid and Display USNG can remain at the default values e Click OK at the top of the window to accept the parameters Note The parameters set in the preceding steps will vary according to the coordinate system of the datasets Loading background raster images e From the Section list menu select Map e From the Layers list menu click Background File The map will be replaced with the Background File selection dialog Figure B4 2 5 Background File OK Cancel Default w Background Vv Sample Background igure B4 2 Background File selection dialog Trimble 2006 e Ensure the Location drop down list menu is set to Device e Set the File Type to Background using the drop down list Automated Geo referenced data entry for agricultural land use 17 The available raster image file s stored on the device should now be listed in the files section at the base of the dialog e Highlight the appropriate raster image for the study area in the Files section e Click OK to return to the map display view Note If the coordinate system of the raster image varies compared to that of the current m
74. e M334 Devonian M730 Subtropics Summer rainfall 02 Granulite M335 Silurian M740 Subtropics Winter Rainfall 03 Eclogite M336 Ordovician M750 Temperate Oceanic 04 Quartzite M337 Cambrian M760 Temperate Continental O5 Marble M338 Precambrian M800 Boreal Oceanic 06 Other metamorphic rock M399 N Soil Surface Aspect Boreal Continental 07 M Lithology Age Geol Parent Mat Bare Rock N1 Polar Arctic 08 Quartenary M400 Soil Surface N2 Moisture Determined LGP Holocene M410 Stony 5 40 N5 Hyperarid 09 Pleistocene M420 Very Stony 40 80 N6 Arid 010 Late Pleistocene M421 Loose and Shifting Sands N3 Dry Semi Arid O11 Middle Pleistocene M422 Stony 5 40 N5 Moisture Semi Arid 012 Early Pleistocene M423 With Dunes N7 Subhumid 013 Tertiary M500 Hardpans N4 Humid 014 Piocene M510 Ironpan Laterite N8 Perhumid 015 Miocene M520 petro Calcic N9 Oligocene M530 PetroGypsic N10 Eocene M540 Hardened Plinthite N11 Paleocene M550 N Soil Subsurface Aspect Mesozoic M600 FAO s Major Soil Groups N12 Cretaceous M610 Jurassic M620 Triassic M630 Automated Geo referenced data entry for agricultural land use 21 Land Cover Classification System ENVIRONMENTAL ATTRIBUTES P Altitude lt 50 300 m lt 50 m 50 100 m 100 300 m 300 1500 m 300 600 m 600 1000 m 1000 1500 m 1500 3000 m 1500 2000 m 2000 2500 m 2500 3000 m 3000 gt 5000 m 3000 3500 m 3500 5000 m gt 5000 m Code P1 P5 P6 P7 P2 PS P9
75. e TerraSync data collection form Select the point feature using a single click or tap This point feature should be highlighted e Click the button labelled Create Data collection for this feature should proceed as described above for the land use feature Once the attribute fields are completed and sufficient GPS positions collected complete feature creation by clicking OK on the data form and returning to the data collection form Closing the Data file If logging of a second survey point is not required then the data file should be closed to allow the GPS unit to be switched off or used in a navigation mode e Ensure the Data section is visible select Data from the section list menu e Display the Collection subsection e Click the button labelled Close Figure B5 4 Collect v E File R102521B 0 create Choose Feature Create Figure B5 4 Closing the data file Automated Geo referenced data entry for agricultural land use 89 e When prompted click Yes to close the data file This data file is now closed and the GPS unit can be switched off or additional data sets for navigation opened Please note that when a further survey point is reached a new file does not need to be created the previous file can be re opened as outlined below Opening an existing data file If surveying multiple survey points within a given area or on a given survey day it may be preferable to store th
76. e characterisation dictionary Sample point point Conservation menu required required Total LUCON1 Partial LUCON2 N A NA default Collection menu required required Plant products LUCOL1 Animal products LUCOL2 N A NA default Figure A3 5 The data dictionary structure within an ASCII format file for definition import The example dataset is that used in the creation of the land use characterisation data dictionary associated with this report This data dictionary concentrates on the creation of menus for each attribute which are populated with text descriptors and associated code values Specification of attribute menus requires the format and data information as outlined in Figure A3 6 Automated Geo referenced data entry for agricultural land use 55 Dictionary Feature 1 Point Line or Area Attribute 1 menu On creation On update Menu item 1 text code value 1 default Where e On creation or on update should be specified as either Normal or Required The normal keyword indicates that a value can be entered for this attribute but the user is not forced to do so Required indicates that a value must be entered for this attribute e Code values should always be enclosed by square brackets e The default keyword indicates that the specified menu item is the default value for the attribute Figure A3 6 ASCII file construction f
77. e data in a single file rather than creating multiple files which contain a single point e Open the Data section of TerraSync select Data from the Sections list menu e Select Existing file from the Subsection list menu The Existing File subsection contains a alphabetised list of existing TerraSync rover files stored on the device e Select the existing file to be opened from the list by single clicking on the file name Once selected the file will become highlighted Note that if the device contains a large number of files the scroll bars at the side of the list can be used to find the appropriate file e Click the button labelled Open As the data file is opened a prompt is displayed to confirm the antenna height Further details on the antenna height are given above e Enter the appropriate antenna height in METRES in the input box e Click OK to confirm The data collection form will automatically open This data collection form will reflect the data dictionary originally specified for the rover file As the GPS parameters were previously set for the data file these parameters which are stored in the file do not to be need to be reset therefore the surveyor is free to continue data collection Automated Geo referenced data entry for agricultural land use 90 6 Processing the Data Following field survey the data files created should be downloaded to the desktop PC fo
78. e following outline is therefore based upon this premise A more in depth description of the database construction and data entry procedure is provided in Section 3 2 Several mapping GPS devices offer a utility to facilitate data entry of attributes in addition to positional information The terminology used to describe these utilities varies between manufacturers for example feature library Thales Magellan MobileMapper or data dictionary Trimble However the functionality offered is very similar For the purpose of this study the examples given will follow the implementation of the Trimble TerraSync software available on the Trimble GeoXT XM GPS units The data dictionary is a flat file database used with the TerraSync software purchased separately with products such as the Trimble GeoXM and Geo XT The database structure is formulated using the Pathfinder Office software product that can be purchased in addition to the GPS unit The construction of the dictionary Appendix A consists of naming the data entry fields and for each field creating a list of potential data entries The completed structure is uploaded to the GPS unit using the data communication program supplied with the GPS hardware Field workers are then able to access the new data dictionary through the normal GPS menu interface Implementing a data dictionary for the land cover and use classification described above requires the user to enter data at each sample point for e
79. e logging interval minimum number of positions and type of GPS information to be collected The final Symbol tab allows the specification of the symbol which will be used to symbolise the feature within the Pathfinder Office and TerraSync software Click OK to accept the parameter settings and create the feature On returning to the data dictionary editor window the new feature should now be included in the feature list Ensure that the data dictionary definition is saved Adding attributes to a feature Once a feature has been created it can be assigned a series of attribute fields These attribute fields will be included in the data collection form within TerraSync for the feature Feature attributes are classified according to the definitions in Table A3 1 This classification influences the type and format of any information recorded in the field for that attribute Table A3 1 Feature attribute types Data Description Type Menu Allows selection of an attribute criterion from a predefined list Numeric Allow numeric value decimal or numeric to be entered during data collection Text Allow a text string to be entered during data collection Date Collect the date of feature creation or update this process can be automated Time Collect the time of feature creation or update this process can be automated Filename Allows the entry of a filename This attribute type is not suppo
80. e sixth holds reference information on which classification databases were used The data tables Figure 1 5 are all related through the sample identity field The contents of the observation land cover land use and photograph tables are prescribed by the information requirements laid down by LUCAS The data could have been stored in a single table however by splitting it into different tables it allows easier break down and analysis of the data The classification reference databases provide the nomenclature information for the land use and cover types These databases have a hierarchical structure that leads the user from a broad classification through to a much more detailed classification Class selection within the application is achieved by stepping down through the hierarchy until the fine detail level is reached Automated Geo referenced data entry for agricultural land use 111 Observation Direction Land_Cover General_Info SamplelD Land_Cover1 Baas Land_Cover2 nea Land_Cover_Notes PSUID SSUID Latitude Longitude ERDE Land_Use ate Time PK FK1 SamplelD Land_Use1 Land_Use2 Land_Use_Notes Photographs Classification c PK FK1 SamplelD Bl Point_code Land_use Point_camera Land_cover Cover_code Cover_camera North_code North_camera South_code South_camera East_code East_camera West_code West_camera Figure 1 5 Pr
81. e sky When satellites are well spaced in the sky relatively to each other then the PDOP value is low and the GPS signal accuracy high PDOP is therefore an indication of the quality of the GPS signal being received the lower the PDOP the better the accuracy of any location measurements Battery status The battery status for the device is indicated in the status bar at the top of the window This is visible whenever TerraSync is in operation Automated Geo referenced data entry for agricultural land use 74 4 Navigation and Background Maps Ideally the surveyor should use standard maps and knowledge of the local area to travel as close to the pre determined survey location as possible Once in the proximity of the survey location the GPS unit should be switched on the TerraSync software initialised and the initial tasks outlined above completed Once the GPS device is tracking sufficient satellites to compute a position the unit can be used to display images and vector data of the area and navigation tools used to refine the surveyors location relative to the survey location Background maps and datasets To aid navigation any raster background maps of the area and the survey locations can be loaded into the Map section of TerraSync The Map section of TerraSync The main elements of the map section are illustrated in Figure B4 1 Lightbar Navigation target Current GPS position Between i feature GPS Navigation path
82. e test program which could be installed separately on the mobile device for quick testing The interface was developed in such away that it could be easily transferred to the main application A GPS receiver produces positional information in a number of formats The most common of these is the National Marine Electronics Association NMEA format NMEA consists of a number of individual data sentences containing information that is based on the first word of the sentence Person 2004 An example of a sentence is GPRMC 132542 584 A 5200 18 N 00025 40 W 3 2 275 35 010806 1A For this application two sentences will be used GPRMC and GPGSA The NMEA data is sent by the GPS receiver to a specific COM port With the GeoXT this is COM 2 The interface consists of a number of processes as detailed in the design stage The first phase accesses the COM port of the GeoXT to which the GPS data is sent by the receiver This was accomplished through the use of the SerialTools tool Having accessed and enabled the COM port GPS data is sent to it The next stage of the interface is to read the data from the port and translate it Figure 2 4 Information is sent to the COM port as data sentences containing all the GPS information The interface identifies the two required sentences GPRMC and GPGSA and breaks them down into their individual words so that the relevant information can be extracted The GPRMC sentence contains coordinate info
83. e widespread in the field of recreational and outdoor activities Units such as the ones shown in figure 5 2 1 can be purchased from one hundred to a few hundred US depending on the unit s functionality amount of memory and pre loaded data Some units can provide detailed mapping for a given area making them particularly powerful navigation devices Automated Geo referenced data entry for agricultural land use 39 Data collection capability is limited to recording waypoints point locations that can later be used for navigation purposes e g you can record the location of your vehicle when hiking or the receiver can be set to record your position at regular intervals whilst moving and this can be displayed on the GPS screen saved and even exported to a PC with a suitable interface cable for use in other programmes However although you can give a meaningful name to waypoints and recorded tracks there is no capability to record complex characteristics at a point location as would be required for the purpose of this application Therefore the use of low cost handheld GPS for land use surveys should only be used as a backup solution to navigation to point locations combined with pen and paper to record detailed land use characteristics Figure 5 2 1 Examples of low cost handheld GPS receivers 5 3 PDA GPS Recently the development of GPS devices that can be connected to a Personal Digital Assistant has been extremely fast It is now p
84. ecsasseeneseesesasbacteasonesvesssoeseesesvessesecues 103 1 DA DS A TN 103 1 1 INTRODUCTION o as 103 1 1 USE CASES a lo den 104 LLI Cote Application iiinn IA A see dade 104 LAD GPS Interface wis cin dlrs aR 106 1 2 USE CASE DIAGRAMS cuisine dla ass 106 1 3 DATA FLOW DIAGRAMS coc da dt dde tas 108 1 4 DATABASE DESIGN iii dt dt ads dd aio 111 1 5 CONCLUSION tdo 112 2 DEVELOPMENT A O i a si i osese iioo ciesa siias ooieoe 113 2 1 INTRODUCTION a cae tone tes dae cies tanner cee eae eee ies eee tee 113 22 PROGRAMMING LANGUAGE addon 113 2 3 ADDITIONAL REQUIREMENTS cc cccccccscssssscececececsesececececeeseseaececececseesaeeeeceeesenssaseeeeeeesenees 113 Automated Geo referenced data entry for agricultural land use 3 2 4 APPLICATION DEVELOPMENTo cccoccconononononononononononononononononnnnnnnononnnononnnnnnnnnnnnnnnnonononcnnnnnnnnnnns 114 PA Bay A Y A E A A A EA O 114 DAD ThEGES Interface ii as aran 116 2 4 3 The Database application psss e ran a ea iaaa ni oia naiean 118 DES INSTALLATION DEPLOYMENT occcococonononononononononononnnnnnnnnnonononnnnnnnononononononnnnnnnnnonononnnnnnnanananen 120 3 FIELD TESTIN Givisessissicssdcseassccssciensseceasssseiassecescsavacseveedacessecvassotvesesvesecessdoseosesvetecabsoteedeneeteanes 120 3 1 INTRODUCTION dd at 120 3 2 METHODOLOGY dida 120 3 3 RESULTS EE E Selected ot ate lee Goce eck Restate dbode tee Ue TATA 121 3 4 DISCUSSION Pepe ee eS 123 3 5 CONCLUSI N sSe
85. ect dialog Additional Information If you have already created a project and wish to continue working in the same folder ensure that the existing project is selected in the project name drop down list at the top of the Select Project dialog 3 Data dictionaries A Trimble data dictionary contains a description of features and their attributes relevant to a particular data collection task A data dictionary can therefore be considered a template for data collection This template provides the outline for data Automated Geo referenced data entry for agricultural land use 49 collection tasks but does not store either the positional or the spatial attribute data of features These are stored in the Trimble GPS Rover file Appendix B The data dictionary can be considered as being constructed from two elements the features to be collected in the field and secondly a list of attributes which describe each of these features Features Features recorded via a data dictionary can be described using either a point line or polygon data structure Feature descriptions can be edited to meet the project requirements and multiple features of the same type are permitted within a single dictionary definition Feature Attributes Attributes are feature specific and take the form of a series of data fields which accompany the standard GPS positional information Fields can be designed to contain numeric or text data entries In addition
86. erence It is therefore recommended that the surveyor test various values An initially suggested value is the default 5m It should be noted that it is possible to disable the close up screen by the selection of None in the Range drop down menu This is not recommended as it may impact on the accuracy with which survey points are located e Set the range in the close up portion of the dialog to an appropriate value i e 5m e Return to the navigation dial window by clicking OK in the navigation options As the navigation target and options are now set the survey point can be located e As stated previously you must be moving to ensure an accurate heading and target direction are calculated Start moving towards the survey location e As you move ensure that the arrow in the direction dial is aligned with your current heading the triangle at the top of the dial e Continue travelling towards the survey location e At the specified range the navigation dial will be replaced by the close up screen Keep travelling until the current GPS location cross and target bulls eye are aligned Automated Geo referenced data entry for agricultural land use 82 Please note that due to varying positional information from the GPS you may find that your current location relative to the sample point changes As a result the true survey location may not be identifiable Judgement may be required as to the location of the sample point re
87. erties window by selecting Data Feature properties e Repeat for the Position Properties window e Select a feature within the map window by clicking on the feature symbol Feature and positional information for the selected feature will be displayed in the feature and position property windows Data Export e Open the Export utility from the main menu Utilities Export or icon located on the main toolbar The Export Utility This dialog based utility is primarily designed to allow the conversion of Trimble data files ssf to GIS or CAD compatible formats When the utility opens the dialog appears similar to Figure B6 1 lola Input Files Folder EALiz o Selected Files Cancel Help Output Folder JENLiz Export Browse m Choose an Export Setup Sample dBASE Setup y Format dBASE Type of Export Features Positions and Attributes Output Option Combine and output to Export folder GIS Coordinate System Site System United Kingdom Zone OS National Grid OSTNO2 Datum Ordnance Survey Coordinate Units Meters New Delete Properties Figure B6 1 The export utility dialog Various types of data recorded by the GPS can be exported of importance to this project are the survey point features positions and their associated attributes During the export process positions can be filtered according to pre defined criteria Warning such a process can le
88. f pro rata In heterogeneous areas concepts of physiognomic importance and dominance are used Eurostat 2003 The land use classification adopted should reflect this provision within the LUCAS methodology 2 2 2 Proposed classification approach The potential number of land use categories that could be applicable at continental regional or national scale is very large As has already been identified it is unlikely that an agreed set of categories and definitions could be formulated that would satisfy all purposes given that government policy is often a major factor driving forward land use classification and this varies from country to country and over time Because policy is subject to change spatially and temporally it is therefore desirable to implement classification approaches that can adapt to changing policy environments This is a strength of the classifier approach inherent within the LCCS Data collected using this method can be formulated into standard or user defined land cover classes The same principle can be applied to land use classification and characterisation Jansen and Di Gregorio 2003 have applied this approach to an area in Kenya Land use was derived from remotely sensed imagery supported by field survey and mapped at 1 200 000 scale The LCCS was used to determine land cover by interpretation of the imagery and from this classification a set of decision rules were established to define land use classes These stu
89. fication scheme in an off the shelf GPS field data collection device is possible but as shown in this report will result in a number of limitations linked to the difficulty of implementing different hierarchy levels This could be solved by the development of a bespoke application within a programming environment or currently available freeware 1 e CyberTracker but to the detriment of the level of future support that would be available for the application developed e To be fully beneficial the GPS field data collection system would need to be combined with an area frame sampling strategy based on a point sample as implemented as part of the LUCAS 2006 survey in Europe The methodology would need to be adapted to African conditions particularly with respect to the stratification approach and would require building capacity in terms of remotely sensed data interpretation e From the GPS devices reviewed it would appear that the Trimble GeoXM unit combined with the TerraSync Professional and Pathfinder Office software packages are best suited for this kind of work whilst offering a high level of flexibility The Thales Magellan MobileMapper unit offers a realistic lower cost alternative but with a slightly lower level of flexibility The implementation of the above recommendations will require extensive training at every stage of the methodology Automated Geo referenced data entry for agricultural land use 44 References Carfagna E 1998
90. finition data must be input during feature creation While this would initially seem advantageous care must be taken in required field definition as drop down menus must be exhaustive This may mean that an additional criterion of Not Applicable needs to be added The addition of this criterion however implies that the surveyor can bypass required fields and not record essential data elements A further consideration when setting required fields is their ease of use within TerraSync After initial criterion selection required field drop down menus are locked In the case of erroneous data entry these fields will remain locked until all required fields have appropriate values specified only then can erroneous entries be re entered A requirement of the data dictionary design is that a surveyor has background knowledge of the land use classification and LCCS in terms of its hierarchical structure and the attribute fields This is to ensure acquaintance with attribute definitions and appropriate data entry combinations This is particularly important as a limitation of the data dictionary design is that no or limited explanatory text can be added to the data input screen to aid data collection in the field It is in this context that the functionality of the GeoXT XM Windows CE environment should be further explored in the development of a stand alone help guide or data collection manual Data storage and export For ease of use the attribute d
91. g EN Distance Units Meters Horas B Area Units Square Meters Height EM Velocity Units Meters Per Second Distance E Use Current Display Units Alea EN Distance Unit Kilometer Velocity EN i e Precision E y Units Time jo gt p Latitude Longitude Options p Date Time Options Format DDD dddddd y Time Format Quadrant F y Date Format MM DDAYYYY y OK Cancel Default Help Figure B6 3 The units tab of the export setup dialog Position Filter Tab e Click the Position filter tab at the top of the dialog The Position Filter tab contains a series of parameters to control the criteria based filtering of positions during export Filtering can be based on a series of parameters including satellite configuration and correction status When setting filters it is important to note that data can be lost If a survey location does not meet the defined criteria it will be excluded from the export and therefore no record will be included in the dBase table As a result land cover and land use survey information will be lost In this export example all features will be exported irrespective of correction or satellite parameters e Ensure that the option Filter by GPS Position Info is selected e Ensure that the satellite parameters are set to minimum values to allow the export of all features o Minimum Satellites 2D 3 or more SVs o Maximum PDOP Any o Maximum HDOP Any e As no real time or post
92. g data assignment Data dictionaries are specific to Trimble and are therefore created in and used with the Trimble software range Data dictionary design and creation is achieved within the Pathfinder Office software although import and editing functionality is also available within the TerraSync software In addition to dictionary creation further functionality is added via the importing of data dictionary definitions using the structure of existing data sources for example Trimble data files or shapefiles As a result of this construction of data dictionaries have the advantages of being able to provide a means of structuring data collection tasks according to the required features of a survey and ensuring data integrity by specifying allowable data inputs While data dictionaries do provide a more complete data collection solution in comparison to a generic data collection template several functionality restrictions can impact on dictionary design Table 3 2 1 outlines some of the general advantages and disadvantages of data dictionary implementation Table 3 2 1 Advantages and disadvantages of data dictionary implementation Advantages Disadvantages Association of a features positional No context sensitive menu control and attribute information in a single file Functionality to ensure standardised No error checking capability to attribute recording ensure logical attribute combinations Functional
93. gricultural LU Characterisation FORESTRY Timber Exploitation clearing selective felling group felling strip felling Harvest Technology manual chainsaw mechanized Code Season Extracted TE1 Dry season extraction TE2 Rain season extraction TE3 Silviculture TE4 crown thinning selective cutting freeing from threatening trees plants HT1 enrichment HT2 sanitary cuttings HT3 SE1 SE2 SL1 SL2 SL3 SL4 Disturbance protected area exploitation via mgmt plans many products without mgmt plans high rate of deforestation DT1 DT2 DT3 DT4 Automated Geo referenced data entry for agricultural land use 15 Land Cover Classification System All CULTIVATED amp MANAGED LANDS I A Life Form of the Main Crop Trees Broadleaved Needleleaved Evergreen Deciduous Shrubs Broadleaved Needleleaved Evergreen Deciduous Herbaceous Graminoids Non Graminoids Urban Vegetated Area s Parks Parkland Lawns B Spatial Aspect Size Large to Medium Sized Field s Large Sized Field s Medium Sized Field s Small Sized Field s B Spatial Aspect Distribution Continuous Scatterred Clustered Scattered Isolated Code Al A7 AS A9 A10 A2 A7 AS A9 A10 A3 A4 A5 A6 All A12 A13 B1 B3 B4 B2 B5 B6 B7 II C Crop Combination Single Crop Multiple Crop One Additional Crop Trees Shrubs Herbaceous Terrestrial Herbaceous Aquatic Simultaneous Overlapping Sequential Trees Shrubs Graminoids
94. gy will be outlined As Pathfinder Office does not support the transfer of shapefiles to the GPS device via the data transfer utility the shapefile must be transferred to the device using the standard My Computer tools e Ensure that the GPS device is connected to the desktop PC via ActiveSync e Open My Computer on the desktop PC e Navigate to the survey point location shapefile use the Copy tool to place this shapefile onto the clipboard Note A shapefile is not a single file when viewed in My Computer Instead the file will consistent of multiple files each with the same file name but varying extensions shp shx prj dbf Ensure all file elements are placed onto the clipboard e Navigate to the Mobile Device GPS unit in the My Computer dialog of the desktop PC As the devices are connected via ActiveSync you should be able to paste the shapefile into an appropriate folder on the mobile device If you cannot see the drives of the mobile device from the desktop PC check the docking cradle cabling and ActiveSync connection Automated Geo referenced data entry for agricultural land use 67 Project Planning A further utility of the Pathfnder software is a project planning tool which is designed to aid the scheduling of GPS field sessions This Quick Plan extension or utility allows prediction of satellite availability at each survey location and determination of the best survey periods based on requ
95. he resultant data Creating a Pathfinder project The Pathfinder Office software is based on the concept of projects Whenever the software is in use the processing tasks must be completed within a project These projects represent a good way of organising your data for example similar files from a survey area or date can be grouped Initially you will create a new Pathfinder project in which to conduct the PC based work for the survey e Open Pathfinder Office from the Start Menu or desktop icon On opening Pathfinder Office the Select Project window should open automatically if it does not open then select File Projects From the Select Project dialog you can open an existing project if a suitable project for your current work has been created or create a new project To create a new project e Click New at the base of the dialog to open the Project Folders dialog Prec Nane j Coment fuvvocreackay 7 June 2006 2 7 28 pn Proc Folder c Prchta Browse Backup Folder Backup Browse A Export Folder Excot Brown y Baco Flo Fodor fixe Broze Covei Delos Heo Figure B2 1 The Create new project dialog e Specify a Project Name A series of invalid characters exist when specifying this name these include characters such as gt and e Press Enter or click away from the input field to accept the new project name The Project Folder field should be automatically updated
96. hich compares the error in between the known and GPS location of the base file as a means of improving the accuracy of rover file or unknown GPS locations This survey will concentrate on the rover file type as data is recorded at a series of unknown locations The survey locations are considered unknown because although the intended survey location is used for navigation there will inevitably be inaccuracy Automated Geo referenced data entry for agricultural land use 84 in the navigation target By determining the actual GPS position a more accurate survey location is recorded e Ensure that rover file is specified in the File Type drop down menu File Name As implied the file name refers to the name of the rover file which will be created When this section is opened TerraSync automatically generates a rover name based on the current date It is suggested that this default file name is replaced with a more descriptive file name The file name should meet standard Windows file naming conventions e Specify an appropriate file name Note the filename is specified using the inbuilt character keyboard This can be accessed from the GeoXT shortcut keys at the base of the screen display Data Dictionary As stated previously data collection will be based on a pre defined template or data dictionary This data dictionary should be specified when creating the new file Once specified this association is permanently embedded within
97. hird stage LCCS dichotomies These files are named according to the feature label specified in the data dictionary e When export is complete an export completed dialog will be displayed This includes a summary of the number of features exported Ensure that the appropriate number of features i e the number of survey points in the file have been read and exported If there is a discrepancy between the number of features read and number exported the export parameters in particular the positional filter properties should be checked e Click Close to dismiss the Export Completed dialog It is important to note that the file naming conventions used in the export are standardised and set by the software As a result on running a second export process the output filenames will already exist hence an overwrite files warning will be generated To prevent file overwrite the original export files should be removed from the export folder and renamed e Using My Computer navigate to the export sub folder of the project folder A series of dBase files should now be present Shapefile Format A further alternative is to export the Trimble data file to an ESRI shapefile for display within a GIS e In the Input Files section of the Export dialog ensure that the imported data file is listed in the selected file list If the file is not listed click on the Browse button in the Open dialog navigate to and open the
98. i sesstissncsss ccgucovaceetescs doseseesbseceassuses cesses ceasbdsseedsveceisanssseetusssosdes 48 CREATING A PATHFINDER PROJECT osre orenetes ara a t a a Te a lea 48 3 DATA DICTIONARIES ssisessicssciscdsossecessbiddeddeisssancesscb steocedensev stotcesonoesbcodateoceecasanedsncd ctscseodesesseteaes 49 THE DATA DICTIONARY EDITOR e oro a ii 50 CREATING A NEW DATA DICTIONARY ooreis anane ia arar a rE oire r r EPEE ONETO TENOS 51 CREA TNG A NAV A ATURE e eiii 51 ADDING ATTRIBUTES TO A FEATURE ccocccccccnccnnnonononononononononononnnnnnnnnononnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnonononcnonanonoss 52 FEATURE AND ATTRIBUTE EDITING cccccccccncncnnnnnnnononononnnononnnnnnonononnnnnnnnnnnnnononononnnnononnnnnnnnonononononananannns 54 APPENDIX B TERASYNC AND DATA DICTIONARY OPERATION MANUAL c00000 58 Te INTRODUCTION sissies sccctssecscstusccdesedsccsssunsccsessdcedsasasessdassecssusceuceesesescudeceeess edesasesasevsusocsesoasedsestensces 58 SOFTWARE AND HARDWARE REQUIREMENTS sccssccecsesessscececececsensaaececececsesssaeceeceeceessaseeeeeeesenensaeees 58 WHAT IS TERRAS YANG A ds 58 STERRASYNG LAYOUT aiii 58 SECTIONS INTRODUCTION c ccccccseseseseseseseseseseseceseseseceseseseseseseeeseseceseseseseseseseseseseeesesesesesesesererenens 59 Automated Geo referenced data entry for agricultural land use 2 NGQVIS ATION A AO TO seceaau hee sunlensaasnnce tes 59 Dalt a iO Slat ose el esto cl ltda de leerlas Stock hla Is Nat Shes ot Sl ok
99. ialog to open the project folders dialog Figure A2 1 Prec Nane j Comment fsvocrmackay 7 June 2005 217028 pn Proc Folder Backup Folder Export Folder Figure A2 1 The Create new project dialog e Specify a Project Name Note that a series of invalid characters exist when specifying this name these include characters such as gt and e Press Enter or click in the next input field to accept the new project name e The Project Folder field should be automatically updated to reflect the default folder for this project By default the project name will be the same as the folder in which data generated by the project will be stored e Ensure that the Project Folder path is an acceptable storage location e The remaining Folder fields can remain on the default settings By default projects created within Pathfinder Office consist of a series of data folders automatically created by the software for use in different tasks Within the main project folder named according to the name specified for the project are three standard folders named base export and backup e Leave the remaining folder field names unchanged to accept the standard folder naming conventions e Accept the new project settings by clicking OK in the Project Folders dialog The settings you entered in the Projects Folders dialog should be reflected in the Select Project dialog e Click OK to close the Select Proj
100. ields in the output table If the current display coordinate system set within the main Pathfinder Office window is appropriate then the following instructions can be disregarded Alternatively an export system must be set e Ifthe current display coordinate system is not appropriate select the Use export coordinate system radio button e Click on the button labelled Change to open the Coordinate Selector dialog Using the drop down menus within the Coordinate Selector dialog an appropriate coordinate system can be set for example in the case of latitude and longitude e Specify Latitude Longitude as the system using the drop down menu e Specify WGS 1984 as the datum e Click OK to accept the coordinate system and return to the parameter setup window dBase Tab e Ensure that the decimal symbol is set to Dot e Click OK to accept the setup parameters and return to the Export Utility dialog Automated Geo referenced data entry for agricultural land use 97 e The changes made to the export parameters should be reflected in the summary at the base of the Export Utility dialog e Click OK to accept the parameters set and proceed with the export The export utility will proceed with the export process and the creation of a series of dBase files A series of files are created as a unique dBase file is created for each feature type i e the land use feature and t
101. in the context of stratification when different sampling rates need to be used e g one replicate is used in mountainous areas and three replicates are used in densely populated rural areas Automated Geo referenced data entry for agricultural land use 33 A systematic sample is often preferred compared to a pure random sample because it is a lot easier to implement over a large area and there is no bias introduced unless the spacing between segments coincides with regular variations in the landscape This is unlikely to occur in most landscapes and perhaps even less in African landscapes Although square segments are largely used throughout Europe particularly following the Monitoring Agriculture with Remote Sensing MARS programme Taylor et al 1997 they would still require the delineation of parcel boundaries inside the segment Figure 4 3 2 which would again present substantial difficulties in most African contexts 492000 256000 493000 255009 3 si tie co Liege si h ES y Figure 4 3 2 Example of a square segment with field parcels 4 4 Point sample The point sample relies on the definition of a series of sample locations positioned around the study area Although these locations are referred to as points they usually cover a small area typically 9 m in the case of the TER UTI survey in France Gay and Porchier 2000 or the LUCAS survey for Europe Delinc 2001 Both TER UTI and the initial LUCAS surveys
102. ing however these tools are too numerous to outline in this document For further information the reader is directed to the Quick Plan help file or Pathfinder Office documentation e Exit the Quick Plan utility File Exit Automated Geo referenced data entry for agricultural land use 12 3 GPS Setup and Initial Tasks The remaining sections of the manual illustrate how the GPS can be utilised to navigate to sample points and record land use and land cover using a data dictionary Prior to using these tools initial tasks should be completed to initialise the GPS receiver Initial tasks Tasks which should be completed once in the field prior to data collection are gt Opening Terrasync gt Check the GPS status and ensure a clear sky view Opening TerraSync TerraSync is available from the start menu of the device on which it is installed Additional shortcuts to the software if installed are the desktop icon open via a double tap and satellite shortcut button F1 adjacent to the GeoXT screen By default TerraSync will open in the Status section Checking the GPS status Prior to checking the GPS status you must ensure that you have a clear view of the sky GPS signals are influenced by buildings heavy tree cover and any objects which will act to block or deflect the GPS signal This condition is true both when starting the GPS unit and during data collection By default TerraSync will open on the Status section
103. ing the implementation of this approach almost impossible 4 3 Square segments In order to overcome the issues of the approach outlined above a simplified approach was developed making use of a square segment with artificial boundaries purely defined on the basis of the map grid without any consideration for any physical boundaries The only requirement linking square segments to their physical environment is to ensure that the size of the segment is such that no more than 50 and no less than 10 parcels are present Gallego 1995 Therefore keeping the same sampling intensity implementing a square segment survey in a landscape with small parcels will result to a larger number of smaller segments compared with a landscape where larger parcels occur Figure 4 3 1 Randomly aligned systematic sample Samples are typically drawn from the combination of the study area boundaries and a grid which is used initially as a series of blocks Figure 4 3 1 The size of each block is a multiple of the segment size and is determined according to the desired sampling intensity The initial position of the grid is selected randomly The position of a segment in a block is selected at random and this position is repeated across the study area ending up in a randomly aligned systematic sample A second and third position can be selected as shown in Figure 4 3 1 These successive positions are known as replicates The use of replicates is particularly useful
104. ion Permanent cropping Wetland cultivation Confined crop production Fisheries production Fishing capture Aqua culture Recreation Mineral extraction Mining Quarrying LUCRP1 LUCRP2 LUCRP3 LUCRP4 LUCRP5 LUFIS1 LUFIS2 LUREC LUMIN1 LUMIN2 Settlement Residential Commercial Industrial Infrastructure Use restricted by security Other LUSET1 LUSET2 LUSET3 LUSET4 LUSET LUOTH Automated Geo referenced data entry for agricultural land use 10 Agricultural LU Characterisation CROPS Crop Type required Avocados CT_572 Grapefruit and Pomelos CT_507 Peas Green CT_417 Bambara Beans CT_203 Grapes CT_560 Pepper White Long Black CT_687 Bananas CT_486 Green Corn Maize CT_446 Pigeon Peas CT_197 Beans Dry CT_176 Groundnuts in Shell CT_242 Pimento Allspice CT_689 Beans Green CT_414 Kapok Fibre CT_778 Pineapples CT_574 Broad Beans Dry CT_181 Kapokseed in Shell CT_311 Plantains CT_489 Broad Beans Green CT_420 Karite Nuts Sheanuts CT_263 Plums CT_536 Cabbages CT_358 Kolanuts CT_224 Potatoes CT_116 Canary Seed CT_101 Lemons and Limes CT_497 Pulses nes CT_211 Cantaloupes and other Melons CT_568 Lentils CT_201 Pumpkins Squash Gourds CT_394 Carrots CT_426 Lettuce CT_372 Rice Paddy CT_27 Cashew Nuts CT_217 Maize CT_56 Roots and Tubers nes CT_149 Cashewapple CT_591 Mangoes CT_571 Seed Cotton CT_328 Cassava CT_125 Melonseed CT_299 Sesame Seed CT_289 Cereals nes CT_108 Millet CT_79 Sorghum CT_83 Cherries C
105. ion that will be acceptable to all It is often the case that national classifications fail to classify pure land use classes mixtures of land cover and land use are found within class names and definitions To a large extent this has come about because of the methods used to collect the land use data Many land use surveys have used remotely sensed data because it can be a cost effective means of mapping large areas of land However only some degree of land use can be inferred from this data by the use of high resolution data sources such as aerial photography Even ground survey may not be able to identify some land uses for example is a forest being used for timber production Within the original LUCAS survey methodology implemented within Europe land cover and land use are treated separately The adaptation of the LUCAS methodology proposed in this report applies this concept within the demonstration data dictionary Land use is more complex in concept than land cover Use can be viewed from different perspectives For example there can be what is often termed a functional use that describes the purpose of the use or a sequential use that describes the operations that take place at the point of observation Young 1998 It is suggested by Young 1998 that both need to be included in a classification intended for a wide range of purposes The US Land Based Classification Standards LBCS adopt this approach and expand the ra
106. ired PDOP and number of satellites constraints The Quick Plan utility is based on the GPS satellite almanac The almanac data set contains time and position information for each GPS satellite orbit An almanac typically contains predicted satellite orbit information over approximately a calendar month To ensure reasonably accurate results the Quick Plan utility requires a current almanac If the desktop PC does not have an almanac or the current almanac is out of date it is important to obtain a current version prior to using the utility Up to date almanacs can be downloaded from two locations Firstly the file can be downloaded from a GPS receiver or datalogger and secondly if a GPS unit is not available a current file can be downloaded from the Trimble internet site www trimble com Updating the Almanac Prior to downloading the current Almanac from the GPS datalogger it is important to ensure that the device contains an up to date file e Outside in an area of relatively open sky turn on the GeoXT unit e Start the TerraSync software from the start menu desktop icon or inbuilt GPS shortcut Fl if available More information on TerraSync and its operation will be given in later sections of this manual The following instructions cover only how to determine the currency of the almanac e Using the drop down menus in the top left hand corner navigate to the Sat Info subsection of the Status screen by ensuring the top menu has
107. is area Interactive panning tool When selected click and drag within the map display to change the focus of the map area Digitise tool This tool can be used to create features within the map display Measurement tool The length between map features or area encompassed by a series of features within the map display can be determined using this tool Options List Menu pasent This list menu contains items which control the map display and enable navigation Specific tools within this menu will be considered in later report sections Layers List Menu Layers 7 This list menu contains tools which control the layers visible within the map display For example tools to control the background view are located within this list Automated Geo referenced data entry for agricultural land use 76 Setting the view coordinate system Prior to viewing the image and vector data the appropriate coordinate system must be set on the device Note The following instructions assume that the coordinate system used for the raster image and survey locations are based on the WGS84 datum The following parameters will need to be adjusted to the map coordinate system used in your country e From the Section List menu select Setup e In the Setup Section click the button labelled Coordinate System to open the Coordinate Systems Parameters dialog e From the System drop down menu select Latitude Longitude
108. it or stored on a computer for processing once the mobile unit has collected data in the field DGPS can achieve accuracies as small as a few cm with the most sophisticated equipment but are typically capable of 2 5m using standard equipment A more transparent implementation of DGPS from a user point of view are the Satellite Based Augmentation Systems SBAS which rely on a network of base stations over a large area continental level The information is then combined into a single signal compatible with SBAS enabled GPS receivers which is broadcast via a geostationary telecommunication satellite There are currently 3 SBAS being developed around the world WAAS Wide Area Augmentation System in North America MSAS Multi function transportation Satellite based Augmentation System for Japan and EGNOS European Geostationary Navigation Overlay System for Europe Accuracies with SBAS enabled receivers are of the order of 2 5m There are plans to extend EGNOS for the African continent but this is not yet operational as the signal currently generated over Africa would not offer any significant improvement on the standalone GPS signal as shown in figure 5 1 2 EGNOS System Test Bed Horizontal Accuracy obtained with combined ESTB MTB monitoring stations 10 JON Troe Ardo HISE 26 00 Es 10 x 2 WINS AAA Figure 5 1 2 Map of EGNOS coverage and estimated accuracy 5 2 Low cost handheld GPS GPS receivers have now becom
109. ity to export coded rather Flat tabular output restricts number of than text descriptors data fields and database structuring Export data to multiple formats Generic features cannot be excluded via the Pathfinder Office software from the dictionary definition suite Ease of data dictionary modification No help system specific to the data within standard window based user dictionary can be developed in the friendly programs standard software setup Only limited training required to implement data dictionary based data collection The restrictions or disadvantages of using the data dictionaries as available in the Trimble TerraSync software could be overcome by the development of a bespoke Automated Geo referenced data entry for agricultural land use 24 software application but this would imply longer development and such a software package would be more difficult to support 3 3 Data dictionary development for land use and LCCS characterisation The basis of the land use and LCCS characterisation developed for this project is the recording of classification category data related to each survey position The following sections outline the design and development of a data dictionary for this collection task set within the constraints of the data dictionary functionality Feature definition The main functionality limitation driving the data dictionary definition in this project is the lack of context sensitive me
110. k M110 Agglomerate M147 Tufa M237 Granite M111 Other Igneous rock M199 Dolomite M238 Granodiorite M112 Sedimentary rock M200 Evaporite M240 Quartz diorite M113 Unconsolidated clastic sed Rock M210 Gypsum M241 Syenite M114 Clay M211 Halite M242 Monzonite M115 Silt M212 Organic rock M250 Diorite M116 Sand M213 Peat M251 Gabbro M117 Gravel M214 Lignite M252 Foidic plutonic rock M118 Loess M215 Coal M253 Ultramatic plutonic rock M119 Loam M216 Tar M254 Igneous hypabyssal rock M120 Colluvium M217 Residual rock M260 Aplite M121 Shells M218 Laterite M261 Pegmatite M122 Cons clastic siliceous sed Rock M220 Bauxite M262 Porphyry M123 Mudstone M221 Kaolin M263 Dolerite diabase M124 Siltstone M222 Other Sedimentary rock M299 Igneous volcanic rock M130 Shale M223 Metamorphic rock M300 Rhyolite M131 Quartzararenite M224 Contact metamorphic rock M310 Dacite M132 Litihic arenite M225 Hornfels M311 Trachyte M133 Feldspathice arenite arkose M226 Spotted slate M312 Latite M134 Graywacke M227 Skarn M313 Andesite M135 Conglomerate M228 Cataclastic metamorphic rock M320 Basalt M136 Breccia M229 Cataclastic breccia M321 Phonolite M137 Mylonite M322 Tephrite M138 Automated Geo referenced data entry for agricultural land use 20 Land Cover Classification System Code ENVIRONMENTAL ATTRIBUTES Regional metamorphic rock M330 Slate M331 Paleozoic M700 O Climate Schist M332 Permian M710 Thermal Climate Gneiss M333 Carboniferous M720 Tropics O1 Migmatit
111. lative to the changing GPS position Once you have reached the survey location you should follow any rules considering the survey in terms of linear features boundaries etc Clear navigation targets and close survey point data file Once you have reached the survey point you are ready to record the land cover and land use information at that location Prior to this however it is necessary to clear the navigation targets and close the sample point locations data file e Return to the Map section of TerraSync select Map from the Sections list menu e Select Clear Nav Targets from the Options list menu e Return to the Data section of TerraSync select Data from the Sections list menu e Ensure that you are in the Update subsection select Update from the Subsection list menu e Click the button labelled Close to close the data file e Click Yes when asked if you are sure you want to close this file On returning to the map view the survey point locations should no longer be visible Please note that closing of the survey point location file is necessary to allow further data collection Once data collection for the current survey point has been completed this data file can be re opened to aid navigation to remaining survey locations Automated Geo referenced data entry for agricultural land use 83 5 Data collection Data collection in this survey will be ba
112. lication so that the end product meets the exact requirements of the end user Detailed design is also an aid to the code development of the application the design provides a map on which to base the code The design in this instance is based on the requirements laid down by LUCAS and the requirements set out in the terms of reference by the FAO The design breaks down into three levels The first level is the identification and definition of the use cases the second is the creation of use case diagrams which show how individual use cases and actors link together The third level is the creation of data flow diagrams indicating in much more detail how data flows through the system and on which the application development can be based Consideration must also be made towards the design and layout of the output database The database design shows the field layout for each table as well as how each table is related 1 1 Use Cases 1 1 1 Core Application Use cases detail the core procedures of the field data application They are generated from the requirements of the project and consist of the actors and use cases that make up the application The GPS interface use case is a standalone item that is essential to the functionality of the application e Create new Project Main flow of events The surveyor selects the Create New Project button that displays the New Project form The surveyor enters the project name and selects which classific
113. log e The selected file for input should now be listed in the selected file portion of the Import dialog By default the output file will be given an alphanumeric name and stored within the project folder It is recommended that the default name is changed to ensure a more descriptive and appropriate file name e Click the Browse button adjacent to the output file to open the Specify Output File dialog e In the Specify Output File dialog specify an appropriate file name for the vector data Click Save to accept this name and dismiss the dialog While several vector data formats are supported the following instructions assume that the vector data is stored in an ESRI shapefile format and that the file is georeferenced to geographic coordinates on the WGS84 datum Import of the other vector formats is similar however the setup parameters may vary Further details can be found in the Pathfinder Office help e Ensure that Sample ESRI Shapefile Setup is selected in the drop down menu under the Choose and Import Setup section e Click the button labelled Properties at the base of the dialog to open the import setup properties dialog The Import Setup Properties dialog contains a series of parameters controlling file import Changing these parameters will influence the characteristics of the imported Automated Geo referenced data entry for agricultural land use 64 data file For the cur
114. mentation of a field survey The methodology would need to be adapted with notably the use of strata definition more representative of the local conditions The LUCAS 2006 approach implemented in Sierra Leone as described in Appendix D results in more than 3 times the number of samples as the 2003 approach but this may be because the sampling rates applied need to be adjusted to the Sierra Leone conditions This could result in a more manageable number of points but the stratification criteria would need to be clearly identified and discussed to ensure they can be easily photo interpreted and are relevant to African conditions As such it would be advisable to carry out a pilot study over a small region perhaps based on administrative units to test the methodology However the implementation of such an approach would also mean that sufficient resources are available to carry out the photo interpretation stage in terms of remotely sensed data availability and technical expertise for the interpretation If these resources were not available then the initial 2002 LUCAS methodology using a 2 stage clustered sample could be implemented Automated Geo referenced data entry for agricultural land use 37 5 Field data collection system 5 1 GPS concepts The Global Positioning System GPS was the first worldwide Global Navigation Satellite based System GNSS Other systems have subsequently or are being developed for example GLONASS in Russia a
115. milar to Figure B6 2 Units Tab e Click the Units tab at the top of the dialog e Select the Use Export Units option Automated Geo referenced data entry for agricultural land use 99 e Ensure that the Export Units are set to meters square meters and meters per second If this not the case click the button labelled Change In the select units dialog which will open automatically using the drop down menus select the specified measurement units Click OK to dismiss the dialog The Export Units tab should appear similar to Figure B6 3 Please note the distance units used in this export are a recommendation and can be changed to meet the surveyors requirements Position Filter Tab e Click the Position Filter tab at the top of the dialog The Position Filter tab contains a series of parameters to control the criteria based filtering of positions during export Filtering can be based on a series of parameters including satellite configuration and correction status When setting filters it is important to note that data can be lost If a survey location does not meet the defined criteria it will be excluded from the export and therefore no record will be included in the shapefile As a result land cover and land use survey information will be lost In this export example all features will be exported irrespective of correction or satellite parameters e Ensure that the option Filter by GP
116. n is contracted Section icon Section N name Map Section list SS button Navigation Seca rop down e B Data list e Status cel Setup Figure B1 1 TerraSync sections and their selection The Map section is the currently active view Adapted from Trimble 2006 Sections Introduction Map The map section is primarily used to aid navigation in the field although it can also aid in field interpretation and surveying The map section allows the user to view features within the current data file in addition to any pre loaded raster or vector background maps of the study area Navigation This section enables the user to navigate from their current location to a pre defined location Information included in the navigation window includes the distance left to travel bearing of shortest path and current heading The direction of travel to achieve the shortest path between the current and target position is also indicated in the form of a direction dial Data This is the primary section used in data collection editing and updating for both positional and attribute information Status The status section allows the user to monitor the current location and health of GPS satellites being tracked by the unit in addition to the current status of both the software and data collection Setup The setup section is split into several sections which allow the parameters determining the behaviour of the software d
117. nd ecological data recording As such further investigations are required to determine the applicability of this software to the collection of land use and cover data within the outlined structure The software is advantageous over the standard GPS software as it allows a greater flexibility of screen design with context sensitive screen sequences Automated Geo referenced data entry for agricultural land use 29 However the recording of GPS location from a single point measurement is not recommended Adaptations to the software to allow the averaging of multiple records for each point should be investigated to improve GPS location accuracy Such investigations are outside the remit of this feasibility study and hence are recommended as further work Automated Geo referenced data entry for agricultural land use 30 4 Sampling strategy 4 1 Background The implementation of the classification approach described above although mainly centred around a point sample could be applicable to both a list frame or an area frame sample the point surveyed could then be assimilated to either the middle of a parcel as part of an area frame sample or the farm in the case of the list frame approach It is understood that a complete census would not be appropriate as the cost would be prohibitive and that the type of sampling to be applied should allow the calculation of the precision of the estimates derived These types of surveys are called probabili
118. nd Galileo in Europe which is still a few years from being operational GPS relies on a constellation of 24 satellites placed in very precise orbits which are closely monitored from the ground figure 5 1 1 Each satellite carries onboard a very precise atomic clock allowing a user with an appropriate receiver to measure the time delay for a standardised signal to travel from the satellite to the receiver The accurate knowledge of each GPS satellite orbit and the combination of time delay measurements from at least 4 satellites makes it possible to calculate an accurate position on the Earth s surface a position can be computed from 3 satellites but a 4 one is required to resolve the uncertainty caused by the fact that the receivers clock is not very accurate Peter H Dana 9 22 98 GPS Nominal Constellation 24 Satellites in 6 Orbital Planes 4 Satellites in each Plane 20 200 km Altitudes 55 Degree Inclination Figure 5 1 1 GPS constellation Standalone GPS units should be capable of accuracies within 15 30m with a clear view of the sky e g tree canopy can affect GPS accuracy GPS positions can be improved using a technique called Differential GPS DGPS which relies on having a second unit placed at a known position base station which will monitor the errors Automated Geo referenced data entry for agricultural land use 38 associated with each satellite This information can either be broadcast in real time to the mobile un
119. ne Satellites below this mask are considered too close to the horizon and therefore too prone to error in position calculation hence they are excluded To enable data collection you must be tracking and considering at least 4 satellites A summary of the number of satellite with sufficiently strong signal and therefore being used to calculate the current position is included at the top of the dialog gt 5 indicating that 5 satellites are being used Please note on initialising the GPS receiver for the first time or after a period of inactivity the unit make take a few moments to determine satellite locations and start tracking During this time the device is receiving the current satellite almanac The almanac is a data file transmitted by the GPS satellites that contains orbital information on all GPS satellites clock corrections and atmospheric delay parameters It is used to facilitate rapid connection to the GPS satellites Position dilution of precision PDOP In addition to the number of satellites being tracked another important consideration is the location of these satellites in the sky Satellites should be well distributed and relatively high in the sky as illustrated in Figure B3 1 These positional considerations are reflected in the PDOP measurement The PDOP measure stated at the base of the dialog is a measure of the quality of the GPS signals based on the geometry of the satellites being used to calculate a position in th
120. nge of use perspectives or dimensions LBCS 2006 It is sufficiently flexible that dimensions can be added or dropped according to the purpose of the survey Within each dimension land use categories can be arranged in a Automated Geo referenced data entry for agricultural land use 7 hierarchy Jansen and Gregorio 2003 and Jansen 2005 also categorise land use on the basis of function and activity and demonstrate the successful implementation of these concepts in Kenya and Albania respectively Classifiers can be developed from this concept adopting the approach used in the LCCS which can be combined in various ways to characterise land use Another concept of importance in land use classification is that of multiple use for example forestry areas may perform a production function as well as provide a recreational use The LANES 1997 programme defines three factors of multiple use that should be considered mapping scale of observation vertical superimposition of uses and temporal mixtures In some classifications multiple use is not considered Remmezwaal 1989 In other classifications the approach is to record what is considered to be the dominant use ECE UN 1989 This may be explicitly defined or implicitly assumed An alternative is to use a pro rata approach Duhamel 1998 The standard LUCAS proforma makes provision for the recording of multiple land uses There should be no calculation o
121. nsity in areas where there will be a high level of variability such as agricultural areas In theory stratification is seen as a good thing but it is often very difficult to implement as there are few datasets of sufficient precision and quality available to assist with its implementation If the stratification is applied using information that is not sufficiently precise and reliable then the outcome is likely to be worse than if no stratification is applied Therefore stratification should only be applied based on criteria that can be easily verified or measured One such example would be elevation areas above a certain elevation can be excluded using a DEM Another example could be water features In the case of the new LUCAS methodology the problems posed by stratification were overcome by the photo interpretation of sample locations into seven strata This approach could also be recommended in an African context as it has the added Automated Geo referenced data entry for agricultural land use 36 advantage of offering a substantial reduction of the sample size in areas where accessibility is often a problem 4 6 Recommendations The benefits of a GPS based field data collection system would be maximised if it was used as part of a point frame sample The approach adopted as part of the 2006 LUCAS methodology is particularly interesting as it would combine the use of remotely sensed data for the stratification stage with the imple
122. ntry phase error checking and handling is taking place ensuring that data integrity is maintained and that all of the required information is recorded An example of this is that the surveyor must enter a land use value the program will not allow them to move to the next stage until this is accomplished Automated Geo referenced data entry for agricultural land use 119 2 5 Installation Deployment For deployment on a mobile device the application is compiled as a Cabinet CAB file This file is then transferred to the mobile device using Microsoft ActivSync The CAB file contains all the information it requires to run including the SerialTools Dynamic Link Library dll file and the ADOCE dll Once copied to the mobile device the CAB file is run which installs the application VB NET creates a number of different CAB files which can be used The CAB files are processor specific so care must be taken when transferring the correct CAB file to the mobile device The application also requires the classification databases to operate These can be created on a desktop PC and transferred to the mobile device in the same way as the application For this application a LUCAS survey database has been created see accompanying CD ROM which contains both the land cover and land use reference information 3 Field Testing 3 1 3 2 Introduction The aim of this test is not to carry out the LUCAS survey but to demonstrate that the new
123. nu controls This has implications in that the variability of the classification category data and the hierarchical nature of the classifications are not easily accommodated Within a bespoke application an ideal solution to encompass the variability of criteria and parameters would be a single survey point feature with attribute recording based on a context sensitive menu system i e selection of preceding criteria would control the appearance of subsequent menus As this is unavailable within the standard data dictionary alternative approaches must be taken i Land use Definition of the land use feature is simple as the land use characteristics recorded are consistent across all sample points Table 2 1 As a result the land use attributes can be attributed to a single land use characterisation feature This separate feature approach as opposed to the inclusion of the land use classifiers within the pre existing LCCS structure is proposed as it ensures the data dictionary is focussed on land use the primary objective of the survey Additionally it reduces the need for lengthy data collection forms which would result from a combination of the land use and LCCS attributes A potential shortcoming of this approach is the requirement for the surveyor to collect multiple features at each sample point one feature for land use and one feature for land cover LCCS Time implications of this double recording are minimised via a reduction in the GP
124. o receive section of the data transfer window e Click Transfer All to commence transfer As the data is transferred the file will be converted from a TerraSync data format to a Trimble Pathfinder Office format ssf This file will automatically be stored in the current project folder e Upon completion a summary dialog will be displayed and an additional text file created within the project folder which contains a summary of the transfer process e Click Yes to view the automatically generated text file or No to close the message dialog Viewing the recorded features Prior to export the recorded features can be displayed within the Pathfinder Office software and their properties interrogated e Ensure that the Map viewer is open in Pathfinder Office If the map window is not visible select View Map from the main menu e Select File Open from the main menu e By default the Open File dialog box should open at the selected project folder If not navigate to the relevant project folder e Select the data file transferred from the GPS this file will have the same name as the rover file e Click Open e On returning to the map window the surveyed location features should be visible Information on these features can be extracted from the Feature Properties and Position Properties windows Automated Geo referenced data entry for agricultural land use 92 e Open the Feature Prop
125. oject database design 1 5 Conclusion With a detailed design for the application complete it is now possible to start developing the application code The design provides the scaffolding on which to build the application By carrying out a detailed design before starting the development process it ensures that the original goals of the project are adhered to The developer will use the design as a step by step guide on how the application should look what its inputs and outputs are and how all the processes link together The design outlines an application that meets the terms of requirements of LUCAS and the project lt creates an easy to use application that supports the hierarchical structure of LUCAS and records the GPS coordinates of the sample points The GPS functionality and accuracy is not as great as that Automated Geo referenced data entry for agricultural land use 112 found in ArcPad or TerraSync but the application is standalone and cost effective 2 Development 2 1 Introduction The overall design of the application detailed in section three is to create and add data to a project database The development process transforms these designs into a working application The development process involves creating the user interfaces and coding the functions of the application Development is carried out in a debug environment allowing the application to be tested as it is built 2 2 Programming Language There are a num
126. ollection and results collation Software and Hardware requirements The following components are required to follow the manual e Trimble TerraSync Professional installed on a Trimble GeoXT XM GPS receiver e Trimble Pathfinder Office and Microsoft ActiveSync installed on a Windows PC What is TerraSync The TerraSync software is designed to allow the collection of GPS and field survey information The software can be installed on both Windows CE devices with or without integrated GPS or on a standard PC If installed on a device with an integrated GPS using TerraSync it is possible to monitor GPS status set GPS parameters navigate to preset coordinates and collect and update feature data This manual will concentrate on the implementation of a field survey using TerraSync Professional Edition It should be noted that a scaled down version of this TerraSync product TerraSync Standard Edition is also available which imposes restrictions on functionality For example the standard edition does not support the display of raster maps or images in the map section covered in section 4 TerraSync Layout TerraSync is arranged into 5 sections one of which is always visible Figure B1 1 The visible section is controlled by the section list drop down located in the top left Automated Geo referenced data entry for agricultural land use 58 hand corner of the TerraSync window The active section is that section visible when the drop dow
127. on actual observations currently exists The work to be carried out in this study aims to assist AGLL in developing a prototype hand held automated field data entry tool that can easily be adapted to varying data collection needs during land use surveys which could be used as a basis for appropriate policy formulation at various scales and also be a crucial input in the formulation of remedial measures in land degradation assessment studies such as LADA It is understood that to undertake a land use survey there is first an essential requirement to identify policy needs for implementing such a methodology at an operational level for an entire country Then a suitable classification scheme will be defined that will enable the acquisition of the necessary data to fulfil these policy requirements It was not possible to include this initial step as part of this study but the authors were careful to define the main lines of enquiry to ensure that the classification methodology adopted could be easily adapted to accommodate policy needs Also although other types of surveys will be reviewed the prototype data collection system developed as part of this work is based around a point sample similar to that applied as part of the LUCAS survey in Europe A manual describing the steps to be carried out to undertake a field survey based on the selected GPS data collection unit and supplied example data dictionary is available in Appendix A A
128. or agricultural land use 114 Data entry is achieved through a sequence of data entry forms that lead the user through the process ensuring that all of the required information is recorded The data entry sequence is split into the specific areas identified within LUCAS i e an observation land cover land use and photographic entry forms The data entry forms for land cover and land use allow the surveyor to select the land cover use type based on the hierarchical structure of the classification system Figure 2 2 Land Cover Informati MN sz ES Land Cover Selection o x Land Cover Please select the an overall land Land Cover 1 Land Cover 2 cover type from the list below Land Cover Figure 2 2 Land Cover Selection forms The final form Figure 2 3 closes the data entry for the sample point The user has the option of moving to the next sample point within the PSU or exiting to a new PSU or the options screen Behind this form code completes the data entry process and saves the sample data to the project database Complete Point Finish Options Please press next SSU to move E 7 to the next SSU or Finish to end Al a e ue the PSU and exit the program e nex or Exit Next PSU Exit Next SSU Finish Figure 2 3 Finish screen and options Automated Geo referenced data entry for agricultural land use 115 2 4 2 The GPS Interface The GPS interface was initially developed as a standalon
129. or definition of a menu attribute The data dictionary structure as specified should be created and edited within a simple text editor and saved with the extension txt It should be noted that rules concerning feature and attribute naming section 2 are still applicable within this method of data dictionary creation and therefore should be adhered to within the ASCII file construction e Within Pathfinder Office open the Data Dictionary Editor from the Utilities menu e Select Import from ASCII file from the File menu Within the subsequent dialog browse to the appropriate ASCII file Click Open The data dictionary editor will now contain the new dictionary structured as specified in the ASCII file This data dictionary should be saved and subsequently modified using the standard utility tools as appropriate Automated Geo referenced data entry for agricultural land use 56 Appendix B Automated Geo referenced data entry for agricultural land use 57 Appendix B Land Cover and Land Use Survey TerraSync and Data Dictionary Operation Manual 1 Introduction This manual outlines the GPS Global Positioning System operation for implementation of a land cover and land use survey based on the supplied data dictionary for data input The manual will focus on implementation of the data dictionary within the TerraSync software on a Trimble GeoXT or GeoXM device including field preparation data c
130. ossible to connect a standard PDA to a GPS add on using a cable or even a wireless Bluetooth connection Some PDAs even have an integral GPS antenna and receiver providing an all in one solution Examples of PDA GPS are shown in Figure 5 3 1 Automated Geo referenced data entry for agricultural land use 40 PDA GPS can be associated with GPS recording software and are still very cost effective as they cost as little as a couple of hundred US to which the cost of the software needs to be added but this is still very attractive pricing Their main drawback is that they are not as rugged as handheld GPS and are more suited for use inside a car or for very occasional outdoor use More ruggedised models are available but their cost is much higher and comparable with mapping GPS units described below The main difference is that they do not provide a fully integrated solution i e the GPS component needs to be integrated with the PDA requiring the connection of each type of equipment together and a software package also needs to be purchased installed and configured separately This would be a disadvantage for land use surveys NAVMAN n s Figure 5 3 1 Examples of PDA GPS 5 4 Mapping GPS GPS manufacturers have developed a range of GPS units which combine GPS receiving capability with the ability to acquire GIS ready features in the form of points lines and polygons It is also possible to include detailed characteristics
131. otter and Nealon 1986 as part of the yearly June Agricultural Survey and Italy FAO 1998 Carfagna 1998 The identification of segment boundaries relies on delineating existing physical and administrative boundaries This means that segments follow an irregular pattern determined by for example rivers roads and hedges Figure 4 2 1 Automated Geo referenced data entry for agricultural land use 31 N 0 y i Figure 4 2 1 Segment with identifiable boundaries hup www nass usda gov research seg0357 jpg It has been successfully applied in the United States where field boundaries and roads tend to follow a regular grid pattern and although it has also been applied in Europe its implementation was made more difficult because of the more irregular field patterns making it difficult to identify segments of similar size The advantage of the method is that the segment size coincides with the parcel size and relying on physical boundaries makes it easy to identify in the field Moreover despite the initial high cost of developing the segment database it can be reused every year and it can also be combined with a remote sensing approach facilitating the digital classification of satellite imagery by making parcel based classification much easier to implement Automated Geo referenced data entry for agricultural land use 32 In an African context parcel boundaries are sometimes very difficult to identify or are non existent mak
132. ow cost solution but only GPS position can be recorded Land use information would have to be recorded on paper GPS PDA would offer the capability of recording land use characteristics as well as GPS positions but these units are not sufficiently rugged Automated Geo referenced data entry for agricultural land use 43 6 Conclusions The technology for a GPS based field data collection system for agricultural land use now appears sufficiently mature and affordable for such a system to be implemented in an African context However the benefits of such a system will only materialise if the following factors and stages are satisfactorily met and correctly implemented e The needs for the collection of such data must be clearly established at the political level This could perhaps be facilitated by the implementation of a pilot study over a limited area to demonstrate the value of the information gathered e An appropriate classification scheme will need to be derived translating the needs expressed at policy level in terms of the data to be acquired in the field It is expected that there is likely to be an iterative process between policy requirements and the data gathered Therefore it is necessary to adopt a flexible approach in terms of the data acquired This will be best achieved if a classifier approach such as the one developed as part of the FAO LCCS is extended to the acquisition of land use data e The implementation of such a classi
133. p Properties dialog The Setup Properties dialog contains all the parameters for the current export setup Changing these parameters will influence the characteristics of the output dbase file For the current export only a small number of parameters need to be changed from their default values Data Tab e Click the Data tab at the top of the dialog e In the Data tab ensure that the Type of data to export is set to Features Positions and Attributes using the radio button and that the drop down menu is set to Export All Features Output Tab e Click the Output tab at the top of the dialog e Ensure the output files is set to Combine all input files and output to the project export folder Attributes Tab e Click the Attributes tab at the top of the dialog The Attributes tab contains options regarding the generated and feature attributes Setting these parameters will influence the fields and data contained in the exported dBase table e At the top of the dialog in the Export Menu Attributes As section click in the radio button adjacent to Code Value 1 to ensure it is selected This is very important as the data dictionary has been constructed to allow the export of coded values As a result each of the attribute fields in the dBase file will contain Automated Geo referenced data entry for agricultural land use 94 an alphanumeric code based on the recor
134. parse trees C Degraded evergreen lowland forest sy Closed grassland N Submontane forest a Irrigated cropland E Mangrove z Waterbodies W J E E Mosaic Forest Croplands Cities 4 Sierra Leone LUCAS 2006 samples Automated Geo referenced data entry for agricultural land use 131 The estimation of the area for a given land use land cover category based on the sample above is as follows adapted from LUCAS 2006 Np 2 Yhi 5 Yst WhYh wh wp h 1 h 1 Nh where D D is the surface of the area of interest Dh is the surface of stratum h For the calculation of variance of land cover area 1 N Wa msi 7 i e N wow 2 Fay h where is the size of the population in the whole region Since a point is considered to have a size 3x3 m N region area in hectares 0 0009 1 N is very small and can be discarded 2 5h is an estimate of the variance of Y not of Y In this case we use an estimate of the local variance 2 0 y y sh Lf 22 0 f WA ey Where h s ij Y is a decreasing function of the distance between i and j dli J For countries where a stratification based on photo interpretation of a pre sample of points regular grid is applied we have for each i 1 Ja y if jis among the 8 closest points to i in the stratum o E When there is no stratification an alternative is a at j if d i j lt 3000 m 0 eS Automated Geo referenced
135. pplication works well it meets the requirements identified in section 1 1 and produces a clearly defined set of results that can be easily used by other software applications There are some improvements and amendments that can be made to future versions of the application and these are detailed in the next sections Automated Geo referenced data entry for agricultural land use 123 4 Future developments 4 1 Introduction There are developments that can be made at all levels of the project The classification system can be developed so that it can be used around the world the methodology can be developed based on changes in the study area and the software can be developed to increase the accuracy of the positioning or incorporate different classification systems 4 2 Classification Systems As discussed in section two the LUCAS classification has its limitations in that it is designed for use within Europe For use within Africa the land cover and use Classification would need to be changed to take in to account the different environments The FAO has its own Land Cover Classification System LCCS that is universally applicable and can be used in any land cover project anywhere in the world LCCS is universal and is not dependent on geographic location and can be adapted for use in any climatic zone and environment Di Gregorio 2005 LCCS is a two phase a priori classification process that generates clear and systematic land
136. quality of the GPS signal and therefore accuracy of the calculated positions When collecting data a limit or maximum PDOP can be set if the PDOP reaches a value above this predefined limit data collection will stop as it is assumed the calculated positions contain too great an error When setting this maximum allowable PDOP value a compromise between accuracy and productivity needs to be made If a low maximum PDOP value is specified the GPS positions recorded can be assumed to be accurate however productivity may be compromised as PDOP values lower than the specified will be less frequently achieved A recommended PDOP value is 6 the default and a commonly used value However the surveyor will have to monitor the productivity implications of this PDOP value e Click the button labelled GPS settings in the Setup section e Ensure the DOP type drop down is set to PDOP Automated Geo referenced data entry for agricultural land use 86 The PDOP limit or mask value can be set using either a slider or manual input The following instructions will focus on slider input e Ensure the box adjacent to the slider bar is checked e Click on the slider bar until an appropriate PDOP value is listed in the Max PDOP field e Click OK to return to the Setup section Data collection e Ensure that the Data Collection form is displayed by selecting Data from the section list menu and Collect
137. r export and processing This download procedure is a valuable way of backing up field data and hence is recommended on a regular basis Connecting the GPS unit to the PC The following tasks require the transfer of files between the PC Pathfinder Office software and the GPS unit Therefore before continuing check that the GPS is connected to the PC Please note that connection between the GeoXT which is a Windows CE device and the desktop PC is enabled by Microsoft ActiveSync This software must therefore be installed on the desktop PC e Ensure that the cabling and docking station are connected The GeoXT connects to the desktop PC via a USB cradle connection Ensure that the USB cable is plugged into both the docking cradle and USB connection on the PC Note that the cradle does not need to be plugged into an electrical socket for data transfer this is only a requirement if the device requires charging e Ensure that the device is seated properly in the cradle e Connection of the device to the PC will automatically open the ActiveSync dialog unless a partnership between the devices already exists Opening an existing Pathfinder Office Project The data from TerraSync must be processed by Pathfinder Office so that the rover files can be converted initially into the Pathfinder format and finally into an export format e Open Pathfinder Office from the Start Menu or desktop icon On opening Pathfinder Office the Select Project
138. re that the GPS is connected to the PC Please note that connection between the GeoXT which is a Windows CE device and the desktop PC is enabled by Microsoft ActiveSync This software which is freely available for download from the Microsoft website must be installed on the desktop PC e Ensure that the cabling and docking station are connected The GeoXT connects to the desktop PC via a USB cradle connection Ensure that the USB lead is plugged into both the docking cradle and USB connection on the PC Note that the cradle does not need to be plugged into an electrical socket for data transfer this is only a requirement if the GPS device requires charging e Ensure that the GPS device is seated properly in cradle e ActiveSync should automatically prompt the user for connection settings Connection can take the form of a partnership or guest connection For details on the most appropriate connection consult the Microsoft ActiveSync help Once a connection is established the ActiveSync desktop icon should become enabled and show as green in colour File Transfer Prior to the field survey the surveyor should ensure that the data dictionary sample point locations and any required background maps are stored on the GPS device Automated Geo referenced data entry for agricultural land use 62 The land cover and land use data dictionary A data dictionary is a description of features and their attributes relevant to a particular data
139. rent import only a small number of parameters need be changed from their default values e In the Import Setup Properties dialog click the tab labelled Coordinate system e The current coordinate system listed should exactly match that defined on the shapefile If the current coordinate system is not correct click the Change button In the dialog which opens set the coordinate system to Latitude Longitude and datum to WGS 1984 Click OK to accept the new system e The remainder of the import settings can be left at the default settings Click OK to dismiss the Import Setup Properties dialog The properties set should now be reflected in the main import dialog e Click OK to proceed with the import The progress of the import will be displayed in a status bar window e When import is complete dismiss the summary window by clicking Close Data transfer Once the raster image s data dictionary and imported vector file s have been collated on the desktop PC they can be transferred to the GPS unit using the data transfer module of the Pathfinder software e The Data Transfer module is opened from the main menu Utilities Data transfer or by using the shortcut on the Utilities toolbar If you have not previously used the data transfer utility then the Device section of the dialog will be greyed out In this case a new device must be specified to allow connection to the GeoXT via the
140. required This export process will result in a series of data files where each file represents the land use or LCCS feature Further modification of these files is largely a function of the export format Automated Geo referenced data entry for agricultural land use 28 3 3 Bespoke application development Bearing in mind the limitations of the data dictionary approach a prototype bespoke application was developed based around the LUCAS 2003 methodology see section 4 4 The application demonstrates that it is possible to develop such a tool but its full implementation would require a considerable amount of programming beyond the scope of this feasibility study Details of the application development and testing are described in Appendix C Due to the considerable amount of programming required in bespoke application development an intermediary solution may be sought Currently available freeware which has the potential to support this solution is the CyberTracker software suite www cybertracker co za CyberTracker The CyberTracker software suite enables the development of an application specific field data collection system for implementation on a Mobile PC with integrated GPS Application development is via a Windows interface in the CyberTracker Standard or Professional desktop software Within this software field data collection application development and testing is considerably less complex in comparison to bespoke programming
141. res can be defined as a point line or polygon area depending on the type of survey and feature being recorded in the field In the case of the current land cover and use characterisation project data will be recorded at a point following the LUCAS survey and hence the new feature should be of this type Click on the button labelled New Feature to open the feature definition dialog Figure A3 2 x Properties Default Settings Symbol Feature Name I Comment Feature Classification E Point Cline Area Figure A3 2 The new feature definition dialog On the Properties tab specify a name for the feature and ensure that the appropriate feature type i e point line or polygon is selected The Default Settings tab contains all the parameters relating to the type of GPS information recorded for the feature including the GPS logging interval minimum positions recorded and type of GPS information code or carrier to be collected These parameters are survey specific and should be set to meet the data collection and accuracy requirements of the project Within the current land use and land cover characterisation project GPS settings of one second code and one hundred are proposed for the logging interval GPS data type and minimum positions respectively Automated Geo referenced data entry for agricultural land use 51 On the Default Settings tab specify appropriate values for th
142. rmation in latitude and longitude plus information on whether there is sufficient data to generate a fix The GPGSA sentence is the precision sentence and contains PDOP HDOP and VDOP information Once the information has been extracted it is stored within a group of variables that can be accessed by the rest of the application The GPS data is sent to the Automated Geo referenced data entry for agricultural land use 116 COM port every second and is recorded by the interface every second Public Sub timGPS_Tick ByVal sender As Object ByVal e As System EventArgs Handles gpsTimer Tick Try Com port is accessed and read every second gpsdata gpsPort Read GPRMC 0 Dim counter As Integer Do While counter lt 500 And gpsdata Is Nothing gpsdata gpsPort Read GPRMC 0 counter 1 Loop Check whether there is data on the COM port If gpsdata Is Nothing Then if there is no data then the program returns you to the beginning MsgBox No data on port Raise an error if there is no data gpsPort Enabled False gpsTimer Enabled False if there is data on the COM port then the data is translated and recorded gpsprecision gpsPort Read GPGSA 0 ReadGPGSA ReadGPRMC End If Catch ex As Exception MsgBox ex Message End Try End Sub Figure 2 4 Sample of code from the GPS interface Within the application GPS data is recorded over the time it takes to enter the point data and then
143. rop down menus are populated with text descriptions for each criterion as specified by the land use classification and LCCS While descriptors are most appropriate to aid data input the criterion codes may be more applicable in terms of data storage and further data processing An advantage of the Trimble data dictionary is functionality that allows relationships to be developed between the text descriptors or drop down menu labels and coded values During export of the data to various formats via the Pathfinder Office software attribute fields can be exported with the text descriptors or coded values Table 3 2 1 states that a disadvantage of the data dictionary is the flat nature of the data storage table This is particularly the case if extensive multi scaled measurements are required at each survey location Within this survey the recorded data is not sufficiently complex to require a relational database structure and therefore the flat table does not limit the data dictionary design or implementation Data output From within the Pathfinder Office software it is possible to export the Trimble data file created from the original rover file into various formats Appendix B As specified previously during export the format of the criteria text or code must be specified in addition to the required tabular fields By default all feature attribute fields will be exported However the surveyor must specify which if any GPS derived fields are
144. roups of Plant Species G3 Statistically Derived Groups G8 Non Statistically Derived G9 G10 G4 G11 G12 Code T1 T3 T4 T2 T5 T6 Automated Geo referenced data entry for agricultural land use 18 Land Cover Classification System Code Code A23 CULTIVATED AQUATIC AREAS I A Life Form of the Main Crop Graminoids A1 S CROP TYPE Non Graminoids A2 Food Crops S1 Woody A3 Cereals S3 B Spatial Aspect Size Fodder Crops S7 Large To Medium Sized Field s B1 Other S13 Large Sized Field s B3 Non Food Crops S2 Medium Sized Field s B4 Crops for Biological Filtration S11 S mall Sized Field s B2 Fibre Crops and Structural Mat S12 B Spatial Distribution Other S14 Continuous B5 Scattered Clustered B6 Scattered Isolated B7 II C Water Seasonality Persistent for Whole Day C1 With Daily Variations C2 Waterlogged C3 MI D Cultural Practices Fallow period Permanent D1 Relay Intercropping D2 Sequential D3 Automated Geo referenced data entry for agricultural land use Land Cover Classification System Code ENVIRONMENTAL ATTRIBUTES L Landform Level Land L1 Pyroclastic rock M140 Calcareous rock M230 Sloping Land L2 Ash M141 Marl M231 Steep Land L3 Lapilli M142 Calcilutite M232 Land With Composite Landforms L4 Scoria M143 Calcarenite M233 Tuff M144 Calcirudite M234 M Lithology Ignimbrite M145 Algal reefal limestone M235 Igneous rock M100 Lahar M146 Travertine M236 Igneous plutonic roc
145. rted by the GeoXT or GeoXM units Separator Separators can be added into the attribute list at any point They do not represent an attribute for data collection but allow data attributes to be broken up into sections to improve readability The dialog used to create new attributes will vary according to the attribute type selected as the parameters required for attribute definition are attribute specific This manual will concentrate on the creation of the menu attribute type as this is the main attribute type used in the land cover and use characterisation dictionary Further details on the creation of the remaining attributes can be found in the Pathfinder Office help Automated Geo referenced data entry for agricultural land use 52 Attributes are assigned to the feature selected in the Feature List of the Data dictionary dialog Figure A3 1 Ensure that the feature created in the previous steps is selected indicated by a blue highlight from this list by clicking on it Click the button labelled New Attribute The New Attribute Type dialog will automatically be opened Figure A3 3 New Attribute Type x Type Add pom C Numeric _ Cancel C Text Help C Date C Time C File Name C Separator Figure A3 3 The new attribute type selection dialog Ensure that the Menu attribute type is selected and click Add This will automatically open the new menu attribu
146. ry features can have multiple attributes therefore the attribute definition process can be repeated to create further attributes Feature and attribute editing Existing features and attributes can be edited or modified Edit dialogs are accessed via the appropriate Edit button ensuring that the feature or attribute for modification is selected Edit dialogs are equivalent to the new dialogs previously outlined Automated Geo referenced data entry for agricultural land use 54 Data dictionary structure Import An alternative to the manual definition of the data dictionary within the editor as outlined previously is the automated import of the dictionary structure This structure can be imported from an existing TerraSync rover file or ASCII format file As import from a TerraSync rover file would primarily form the basis of data dictionary modification this manual will concentrate on ASCII import as a means of new dictionary definition To enable import from an ASCII txt format the file must be constructed in the appropriate format as expected by the Pathfinder software Figure A3 5 illustrates this structure via the data model and based on an example dataset Data model Dictionary Feature 1 Point Line or Area Attribute 1 Menu Numeric Char Date Time Attribute value 1 Attribute value 2 Attibure value n Attribute 2 Attribute n Feature 2 Feature n Example data Landuse Dictionary Land us
147. sed on a pre defined data dictionary This data dictionary was transferred to the device in section 1 in this appendix At the first survey location a new data file should be created in which to store the feature and attribute data At subsequent survey locations this initial file can be re opened Both of these tasks in addition to data recording are achieved in the Data section of TerraSync Data file creation e Open the Data section of TerraSync select Data from the Section list menu e Select New File from the Subsection list menu to open the Create New Data File form Figure B5 1 Ple Norme post 7144 Oeteray Hare Figure B5 1 New data file creation form Trimble 2006 In the Create New Data File form you must specify the file type file name and data dictionary File Type Two types of data file rover and base exist within the TerraSync software Rover Files A rover file refers to a file created on a mobile GPS device Typically the location of features recorded within this rover file are not accurately known Base Files A base file differs to a rover file in that the location of the GPS device at which data 1s being recorded is known The purpose of this base file or base station GPS is to record the derived GPS position at a known or reference location Recorded concurrently with a rover file this information is typically used for differential correction a process w
148. status listed and Sat info is selected from the bottom menu as illustrated in Figure B2 4 Automated Geo referenced data entry for agricultural land use 68 stas 5 x _ PrN ti sie fio snr eier arc 04 40 Almanac 5 16 06 PDOP 2 08 Productivity Precision gt Figure B2 4 The satellite information window as a means to check almanac currency Trimble 2006 The TerraSync window should appear similar to that in Figure B2 4 please note that there will be some variation as the satellites being tracked will differ as will the GPS settings in the status bar The date of the almanac last received by the device is listed towards the bottom left of the dialog for example 16 May 2006 in Figure B2 4 If the date is not current within a month or is replaced with a question mark there is no current almanac In this case ensure a clear sky view and allow time for the device to receive satellite broadcasts containing the new almanac Once a new almanac is received a small message will appear in the status bar at the top of the display Downloading the almanac After ensuring a current almanac is available on the device this can be downloaded to the desktop PC If Pathfinder Office was closed after data transfer the following tasks are required to re open the existing project e Open Pathfinder Office Almanac transfer must take place within a Pathfinder Office project As a project was previously create
149. t a cost of 29 95 To enable the testing of the application before installation on the mobile device a standard emulator supplied with Visual Studio is used which mimics the operation of the mobile device This saves time and allows the programmer to debug the program before final release to the mobile device To check the GPS interface a further emulator is required GpsGate allows you to simulate a GPS and send the signal to a specified COM port GpsGate is available from Franson at a cost of 29 95 For this project a free trial version of GpsGate was sufficient Application Development Development of the application was split into three identifiable stages Firstly the graphical user interface GUI was created This is the interface that the surveyor uses for accessing the functionality of the application Secondly a test GPS interface was developed which enables the full testing of this primary component before it was installed in the main application Finally the main application coding was generated 2 4 1 The GUI The GUI consists of a sequence of forms allowing the surveyor to select and add data to the project database The primary form Figure 2 1 is the main options screen From here the user is able to create new projects setup the GPS interface and add data to the project Field Data Collection ml Setup GPS New Open Exit GIA Figure 2 1 Main options form Automated Geo referenced data entry f
150. t the navigation dial will be replaced with the close up screen Figure B4 5 Current GPS position Target Message line Information fields Figure B4 5 The close up screen Trimble 2006 The close up screen is designed to enable the surveyor to accurately locate the required survey location This is achieved by aligning the current GPS position cross centrally on the target circular bulls eye The close up screen is aligned relative to the current heading when the screen is first opened This heading or alignment is not updated on the close up screen therefore it is recommended that the surveyor travel forward backwards and sideways if necessary to align the current location and target rather than turning sharply The close up range distance at which the navigation dial changes to the close up screen is specified within the navigation options list menu Setting the navigation target e Display the Map section of TerraSync select Map from the section list menu e Ensure that the dataset containing the survey locations is open within the map display as discussed above e Using the zoom tools zoom in on your current location and surrounding survey locations e Select the Select tool from the map tools list menu a e Tap or click on the survey point to which you wish to navigate This point should now be selected indicated by a square selection area and the feature attributes displayed on the screen
151. te dialog Figure A3 4 Edit Menu Attribute x OK Cancel Help Conservation Attribute Name Comment m Menu Attribute Values Name User Code 1 User Code 2 Total LUCON1 Partial LUCON2 ANA NA Edt Delete 4 Field Entry On Creation On Update Normal Normal Required Required C Not Permitted Not Permitted Figure A3 4 The new edit menu attribute dialog The New Menu Attribute dialog allows the specification of the criterion which will appear in the attribute drop down list These criteria can be represented via a text descriptor in addition to a coded value During data collection the surveyor will be presented with a drop down menu based on the text descriptors however the coded values will be transcribed to the file and can be extracted during data export Automated Geo referenced data entry for agricultural land use 53 The criteria for the menu attribute values are added via the New Menu Item dialog which is accessed via the New button Figure A3 4 Criteria parameters entered in this dialog include the text descriptor and up to two coded values As criteria are added they are included in the Menu Attribute Value list in the order they will appear in the drop down menu Figure A3 4 The default attribute value is indicated in this list with an asterisk This default value is specified via a check box in the New Men
152. the rover file e Using the drop down menu ensure that the dictionary name reflects the survey specific data dictionary file transferred to the device in section of this appendix e Click the button labelled Create to finalise the settings and create the new data file As the new data file is created you will be prompted to confirm the antenna height The antenna height refers to the distance between the integrated antenna on the GeoXT unit and the ground This measurement is required to ensure accurate GPS position calculations e Enter the appropriate antenna height in the input box using the inbuilt keyboard Note that antenna height should be entered in METRES When working with the GeoXT unit the antenna height is easily varied according to how the unit is held due to its integrated receiver construction To try and ensure consistency it is recommended that a comfortable holding position is consistently used Alternatively a pole or tripod of known height can be used to support the device Once the antenna height is specified the Collect data form will automatically open GPS settings This manual will not provide an exhaustive description of all GPS parameters and settings available within the TerraSync software A limited number of parameters will be considered as setting these parameters is required for data collection Additional parameters are set within the data dictionary these parameters will be loaded by default
153. the status dialog outlining the parameters for the current session Now that a point has been created and a survey date specified information on the number and geometry of satellites at the point on the specified date can be visualised e From the main menu in the Quick Plan window select Graphs Number SVs and PDOP A graph should be created in the main window which plots the number of satellites and PDOP against time The time axis represents the survey date selected split into 4 hour sections Within the graph Quick Plan uses colour to distinguish different types of information for example magenta is used to indicate greater than 11 satellites while red indicates less than 4 with a gradation of colours in between Automated Geo referenced data entry for agricultural land use 71 Low PDOP adequate number of SVs High PDOP marginal number green cyan blue or magenta of SVs red or yellow Figure B2 5 Interpretation of the Quick Plan PDOP graph Using the graph it is possible to identify periods during the day when the number of satellites visible or satellite geometry at the survey location will be poor i e PDOP high number of satellites low indicated by yellow or red bars The identified time periods should be avoided for field survey Figure B2 5 indicates how to interpret the graph The Quick Plan utility has a variety of further graphical display and parameter settings which can be used to further refine survey plann
154. tical Precision Horizontal Precision Standard Deviation Correction Status Receiver Type Date Recorded W Point ID Time Recorded Update Status xl Line Features Area Features Length 2D rea 2D Length 3D JPerimeter 2D Average Vert Precision Average Horiz Precision Worst Vert Precision Worst Horiz Precision Line ID JPerimeter 3D Average Vert Precision Average Horiz Precision worst Vert Precision Worst Horiz Precision xl OK Cancel Default IE Figure B6 2 The attribute tab of the export setup dialog Units Tab e Click the Units tab at the top of the dialog e Select the Use Export Units option e Ensure that the Export Units are set to meters square meters and meters per second If this not the case click the button labelled Change In the Select Units dialog which will open automatically using the drop down menus select the specified measurement units Click OK to dismiss the dialog The export units tab should appear similar to Figure B6 3 Automated Geo referenced data entry for agricultural land use 95 Please note the distance units used in this export are a recommendation and can be changed to meet the requirements of the surveyor x Data Output Attributes Units Position Filter Coordinate System dBASE r Units m Decimal Places Use Export Units Lat Lon
155. tion within the TerraSync software on a Trimble GeoXT or GeoXM device As the manual is intended only as a brief introduction to data dictionary creation the reader is referred to the Pathfinder Office manual for further information Software and Hardware requirements The following components are required to follow the manual e Trimble Pathfinder Office installed on a Windows PC 2 Pathfinder Office Pathfinder Office is the PC based software that accompanies Trimble GPS units needs to be purchased separately This software provides tools which enable users to plan GPS surveys and successfully download and process the resultant data Creating a Pathfinder project The Pathfinder Office software is based on the concept of projects Whenever the software is in use the processing tasks must be completed within a project These projects represent a good way of organising data Prior to data dictionary creation and editing a Pathfinder project must be created e Open Pathfinder Office from the Start Menu or desktop icon On opening Pathfinder Office the Select Project window should open automatically if it does not open then select File Projects From the Select Project dialog you can open an existing project if a suitable project for your current work has been created or create a new project Automated Geo referenced data entry for agricultural land use 48 To create a new project e Click New at the base of the d
156. tionary see figure 3 3 1 www These features meet the requirement that attribute data fields and criteria are static If the features were derived from any higher level of the LCCS hierarchy this requirement would not be met For example a feature defined as terrestrial at the second level of the hierarchy could be Cultivated and Managed or Natural and Semi natural Vegetation as the required data attributes for these cover types varies they cannot be accommodated and hence are split into the two feature types Definition of features at the third hierarchical level does mean that not all levels of the LCCS classification are implicitly recorded However from the features at the third level all previous hierarchical elements can be implied so no information is lost Although not recorded the surveyor must use knowledge of the previous hierarchical levels to decide which feature type is the most appropriate for each survey point E bata v oh 8 Collect Options Close File RO124104 Choose Feature 0 create Type Feature Name LocsCultivate Mng TR LECS Cult AQ LOCSNat Semi Nat TR x Point_generic os Line_generic Area_generic Figure 3 3 1 TerraSync feature selection form of a rover file implementing the LCCS and land use demonstration data dictionary The preceding discussion implies that the data dictionary only contains the features relating to the LCCS and land use elements A limitation
157. ty sample surveys FAO 1996 and are usually defined according to the way in which the sampling units are identified These are e List frame survey Sample units are drawn from a list of land owners typically identified by their name and addresses These types of surveys have traditionally been used extensively for agricultural statistics FAO 1996 and are used in a number of European countries However to be reliable the list requires frequent update The list is particularly difficult and expensive to update when there are a very large number of land owners and where communications are not well developed As this is clearly the case in an African context these types of survey are not recommended within the scope of this study e Area frame survey Sample units correspond to areas of land which are often referred to as segments The entire study area is divided into non overlapping segments and a selection is drawn from the total population to derive the sample Depending on the type of segments area frame surveys can be further sub divided into o Segment with identifiable boundaries o Square segments o Point sample The area frame sample approach is one that is better suited to this type of work because it does not require any a priori knowledge of the stakeholders as is the case for list frame surveys 4 2 Segment with identifiable boundaries This type of approach has been widely applied in many countries notably the United States C
158. u Item dialog Specify a name for the new attribute using the text box at the top of the Edit Menu Attribute dialog This name should be unique and not contain more than 20 characters Click New to add a menu item to the current attribute Complete the text descriptor and coded value fields for the first menu item Note that the text descriptor and coded value are limited to 20 and 6 characters respectively Click Add to accept these parameters and create the menu item Repeat this process until all attribute criteria menu items have been entered ensuring that the Default checkbox is selected for the appropriate criteria A final requirement of the attribute definition is to specify whether the attribute is a required field If an attribute is defined as a required field a value must be specified for this parameter during data collection Alternatively the attribute can be defined as normal data entry is optional or not permitted or data entry is not permitted The latter option is used in cases where the attribute is automatically generated This is repeated both on creation i e when the feature is first created and on update i e if the feature is later modified At the base of the Edit Menu Attribute dialog specify whether the attribute is a required field on creation and update using the radio buttons Finally click OK to accept the new attribute definition Within a data dictiona
159. ure 5 4 1 MobtileMaepper THALES Figure 5 4 1 Examples of handheld Mapping GPS units not to scale relative to one another Differential GPS could be implemented with two mapping GPS units with the aim to improve the precision as described in section 5 1 This second unit would then be placed at a fixed known location for the duration of the field work GPS data are recorded by both units and downloaded to a PC with GPS processing software installed such as Trimble Pathfinder Office or Thales Magellan Mobile Mapper Office The field unit data is then post processed with the base station data to achieve a higher level of accuracy The level of accuracy that could be achieved varies primarily on the type of processing applied and the distance between the field unit and the base station The highest accuracy would be achieved with carrier phase processing and can be obtained using a suitable GPS unit and associated software such as the Trimble GeoXT and TerraSync Pro or Magellan ProMark III to decimetre level provided that the field unit is less than 100km from the base station Metre level accuracy would be achievable with most mapping GPS units using code phase processing provided the field unit is less than a few hundred km from the base station Automated Geo referenced data entry for agricultural land use 42 If real time processing was necessary this would require the acquisition of additional equipment to
160. ure 1 2 has been generated providing an outline of how the interface should operate Automated Geo referenced data entry for agricultural land use 107 GPS Interface Access COM Port Extract Coordinate Data Calculate Precision GPS lt lt Actor gt gt amp Coordinates Extract Precision Data Figure 1 2 GPS Interface Use Case diagram The use cases provide the raw structure of the application identifying what is required of the application and how each section is linked For further development a more detailed design and structure is needed 1 3 Data Flow Diagrams The use cases detailed above provide an outline for the functionality of the application For more detailed planning a set of data flow models are produced Data Flow Diagrams DFD depict the flow of data through a system plus any processing that the system performs Whitten et al 2001 The data flow diagram allows a developer to visualise what is required for the development of the application Figure 1 3 The application designer starts with an overall DFD and progresses through each process creating new more detailed DFD s until no further breakdown is possible this is known as process decomposition Decomposition is the breaking down of a system into its component subsystems processes and sub processes Whitten et al 2001 For this project we will focus on one specific process that of the GPS interface Automated Geo referen
161. urrent GPS location the vector data should also be visible If the background layer is not visible ensure that the layer visibility is enabled The background layer is visible if the Background option is checked within the layers list menu Figure B4 3 By checking and un checking this option the background layer visibility can be toggled between visible and hidden Automated Geo referenced data entry for agricultural land use 78 Loading the survey point locations While the survey point locations are vector data they will not be loaded into the map view using the background layer approach A disadvantage of viewing vector data files within the background layers of the map display is the loss of feature attributes While the feature attributes are held in the data file the map section is designed to eliminate this information to minimise computing requirements In the case of the survey locations the tabular data or feature attributes contain important information regarding the survey points To ensure this information is available to the surveyor the data file will be opened within the data section of TerraSync Opening the survey point data file in the data section will allow attributes to be viewed by the surveyor A disadvantage of this approach is the potential size of the resultant data file and associated attributes If the original shapefile contains a large number of sample points the surveyor should consider splitting the file into
162. urveyor to the port selection interface Exceptional flow of events If the PDOP value rises above a user defined level a prompt is raised and the collection of GPS data is suspended until the value is lower than the threshold again Exceptional flow of events If GPS data is lost the surveyor is prompted and returned to the start of the sample point data collection process The surveyor is prompted to wait for coverage to return 1 2 Use Case Diagrams Combining the uses cases and defining the links between them allows the designer to demonstrate the full functionality of the application This functionality can be described through the production of use case diagrams Use case diagrams describe graphically the interactions between the systems the system components and the users Interaction between the core components is through the actor Surveyor Figure 1 1 Further detail is introduced as the core account use case is broken down into its component parts In these instances there are interactions shown between both the user and other system components Automated Geo referenced data entry for agricultural land use 106 Core Application Create New Project Open Existing Project Surveyor Close Project Figure 1 1 Core Application Use Case diagram One of the main components of the application is the GPS interface This allows the application to connect to a GPS receiver and record GPS coordinates A use case Fig
163. utomated Geo referenced data entry for agricultural land use 5 2 Classification scheme 2 1 Background Classification is the process by which features can be allocated to defined categories by matching their attributes to individual category definitions through the use of diagnostic criteria This produces a simplified representation of reality Each category in the classification will normally be assigned a name and description providing the user with the information required to interpret the classification result The diagnostic criteria used in the classification should be clear precise preferably quantitative and objective Land classification systems have been developed for many purposes for example characterisation of soils land capability assessment land suitability assessment land cover and land use mapping It is the latter two examples that are pertinent to this report A common requirement for these types of classification is that they should be scale independent 1 e the categories can be applied to any mapping scale and source independent i e a range of data sources could be used to collect information Many attempts have been made to develop land cover and land use classifications Land cover is the observed bio physical cover of the earth FAO 2005 The Land Cover Classification System LCCS FAO 2005 is formulated on the principle of defining land cover classes by the combination of a set of diagnostic criteri
164. ween the application position and the TerraSync position will be calculated as a comparison Results The project database created during the field test contains six tables that can be related through the sample ID number Figure 1 5 These tables contain the data collected during the field survey some of this data is generated automatically but most is generated through the user interface The general information table Table 3 1 contains the broad information on the survey i e sample number surveyor identity and sample coordinates The sample point observation land cover Automated Geo referenced data entry for agricultural land use 121 Table 3 2 land use and photograph reference information is contained in separate tables Table 3 1 General Information database table SAMPLEID USERID USERNAME PSUID SSUID LONGITUDE LATITUDE PDOP DATE TIME 00111 gg06 Graeme Gould 001 11 0 440379624652778W 52 0056874142361N 3 07 08 2006 03 56 08 PM 00112 gg06 Graeme Gould 001 12 0 43999245W 52 0057676172515N 3 07 08 2006 03 57 58 PM 00113 gg06 Graeme Gould 001 13 0 434612746341463W 52 0058640752033N 2 07 08 2006 04 06 05 PM 00114 gg06 Graeme Gould 001 14 0 429301242718447W 52 0056929647249N 3 07 08 2006 03 06 52 PM 00115 gg06 Graeme Gould 001 15 0 424733943333333W 52 0054578925N 3 07 08 2006 03 12 36 PM 00121 gg06 Graeme Gould 001 21 0 441777756770833W 52 002758165625N 4 07 08 2006 03 49 32 PM 00122 gg06 Gr
165. xt sensitive As a result variables in drop down menus cannot be refined based on preceding selections resulting in lengthy drop downs and perhaps more seriously inappropriate data entry as no error checking against previous attributes is available No solution to this issue has been found for the current data dictionary The definition of appropriate default values for drop down menus and menu clarity in terms of sections and sub sections indicated by marks Figure 3 3 2 may reduce errors resulting from illogical criteria combinations but this is not a rigorous solution gt TerraSync B Data O Collect Options v b gt 1 Cultivated Managed Bo Cancel A Survey Point ID Survey Date 15 11 2006 Survey Time 09 49 45 LifeForm Main Crop LifeForm SpatialSize Shrubs Broadleaf LifeForm Distribute Needle Evergreen Crop Combination Deciduous Herbaceous Cultural Prac Water Cultural Prac Time Crop Type Eny Landform Env Lithology Envy Lith Parent Mat Env Soil Surf Aspect ee y ol Env Soil SubSurf ze Figure 3 3 2 TerraSync feature attribute collection form attribute fields reflect the selected feature type of Cultivated and Managed Automated Geo referenced data entry for agricultural land use 27 In addition to drop down menus data input can be further standardised by the definition of required fields If an attribute field is marked as required within the dictionary de

Feasibility study on automated geo

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