Global Positioning System Data Collection Guidelines
Publication date: 2011
Global Positioning System Data Collection Guidelines MARCH 2011 This publication was produced for review by the U.S. Agency for International Development. It was prepared by the USAID | DELIVER PROJECT, Task Order 1. Global Positioning System Data Collection Guidelines The authors' views expressed in this publication do not necessarily reflect the views of the U.S. Agency for International Development or the United States Government. USAID | DELIVER PROJECT, Task Order 1 The USAID | DELIVER PROJECT, Task Order 1, is funded by the U.S. Agency for International Development under contract no. GPO-I-01-06-00007-00, beginning September 29, 2006. Task Order 1 is implemented by John Snow, Inc., in collaboration with PATH; Crown Agents Consultancy, Inc.; Abt Associates; Fuel Logistics Group (Pty) Ltd.; UPS Supply Chain Solutions; The Manoff Group; and 3i Infotech. The project improves essential health commodity supply chains by strengthening logistics management information systems, streamlining distribution systems, identifying financial resources for procurement and supply chain operations, and enhancing forecasting and procurement planning. The project also encourages policymakers and donors to support logistics as a critical factor in the overall success of their health care mandates. Recommended Citation USAID | DELIVER PROJECT, Task Order 1. 2011. Global Positioning System Data Collection Guidelines. Arlington, Va.: USAID | DELIVER PROJECT, Task Order 1. USAID | DELIVER PROJECT John Snow, Inc. 1616 Fort Myer Drive, 11th Floor Arlington, VA 22209 USA Phone: 703-528-7474 Fax: 703-528-7480 Email: firstname.lastname@example.org Internet: deliver.jsi.com Contents Introduction .1 Setting Up the GPS Device for Data Collection .3 Deleting Old Waypoints .5 Turning on the GPS and Acquiring Satellite Signals.7 Choosing Where to Collect Waypoints.7 Marking Waypoints . 9 Reviewing and Editing Waypoints.11 Additional Options .11 Downloading GPS Data to a Computer .13 Downloading Data.13 Exporting Waypoints .15 References.17 iii iv Introduction Using Geographic Information Systems (GIS) information as part of a facility-based supply chain assessment helps identify logistics issues that may be specific to certain areas of a country. Overall, GIS adds value to information that is obtained with the Logistics Indicator Assessment Tool (LIAT) by increasing ways data can be used and by providing a simple method for visually demonstrating results. GIS information is drawn from global positioning system (GPS) coordinates or waypoints, which are key data (e.g., latitude and longitude) for pinpointing a particular location. Coordinates are determined by using an electronic mapping device to capture information from GPS satellites. This document provides basic instructions for recording health facilities’ GPS coordinates using the Garmin etrex Venture® HC, a commercially available mapping device. A complete owner’s manual, including descriptions of advanced operations and troubleshooting advice, can be downloaded from: http://www8.garmin.com/manuals/eTrexLegendHCx_OwnersManual.pdf 1 2 Setting Up the GPS Device for Data Collection Before collecting waypoints for health facilities, it is important to ensure that data captured by the GPS device will fit the format that is recommended for use with the LIAT. To do this: 1. Choose on the Main Menu screen. 2. Click on the Enter/Rocker button. 3. Choose on the Setup Menu screen. 4. Using drop-down menus on the System Setup screen: a. Set GPS to Normal. b. Disable the WAAS/EGNOS option (which is used almost solely for aviation purposes in North America and Europe). c. Confirm the type of battery you are using to run the device. d. Confirm the language you prefer to use. e. Set the External Power Lost option to Stay On. 3 .5. Go back to the Setup Menu screen and choose 6. On the Units Setup screen: a. Set the Position Format as hddd.dddddº (decimal degrees). b. Set the Map Datum (i.e., the digital model of the earth on which the geographical coordinates will be based) to WGS 84. c. Set the Distance/Speed to Statute (miles) or Metric, depending on the unit of measurement used in the country being evaluated. d. Set Elevation to Feet (ft/min) if Statute was chosen for Distance/Speed. Set the Elevation to Meters if Metric was chosen for Distance/Speed. e. Set Depth to Feet (ft/min) if Statute was chosen for Distance/Speed. Set the Depth to Meters if Metric was chosen for Distance/Speed. 4 Deleting Old Waypoints To avoid confusion, delete all waypoints stored in the GPS device before beginning a new assessment. Check with the previous users to ensure that they have documented their waypoints. Download the waypoints (see page 7 of this document) if you are unable to confirm they have been documented or if there is any doubt about the completeness or accuracy of the records that were retained. To delete all waypoints together: 1. Choose on the Main Menu screen. .2. Select 3. Click the Find button. 4. Select Delete. 5. Select All Symbols. 6. Confirm Yes when asked: Do you really want to delete all waypoints?* To delete waypoints one by one: 1. Choose on the Main Menu screen. .2. Select 3. Scroll down and select the waypoint you want to delete. 4. Use the rocker to select the Delete button. 5. Confirm Yes when asked: Do you really want to delete all waypoints?* * It is important to note that there is no undelete option for waypoints you’ve deleted. 5 6 Turning on the GPS and Acquiring Satellite Signals As soon as the GPS device is turned on, it will automatically search for satellite signals. If the device is being activated less than 100 kilometers from its last point of use, start-up will take only one to three minutes (known as a warm start), because signals probably will be acquired from most or all of the previously used satellites. Restarting at a distance of more than 100 kilometers generally takes longer than five minutes (known as a cold start). At first, light blue-colored icons representing all satellites within a reasonable range will appear on the device’s field of view screen. When a constant signal is acquired from a specific satellite, its corresponding icon will turn dark blue. Once constant signals are acquired from at least four satellites (the minimum number needed to identify a waypoint), the screen will then show that the GPS unit is ready to navigate and will provide a waypoint for the spot-of-use. The waypoint is generally considered to be accurate to within 10 to 30 meters. To return to the field of view screen at any point during use of the device, go back to the main menu and select . Choosing Where to Collect Waypoints GPS readings that are taken in open areas outdoors are the most accurate because satellite signals can be distorted by concrete and tall obstacles. Ultimately, the decision on where to capture the waypoint for a health facility is a balance between proximity to the target location and the ability to acquire a good signal from satellites. A GPS reading should never be taken indoors and is best captured 20 to 30 meters away from potential obstacles. If the intended GPS point is meant to represent multiple buildings, standing near the main entrance of the complex is recommended. 7 It is sometimes difficult to get an open view of the sky in urban areas due to tall buildings, and in wooded areas due to high tree canopy. If you are unable to make sufficient contact with satellites when standing at the entrance to a facility, identify the closest open area (e.g., parking lot, road intersection, or clearing) and position yourself at the center of that location. Be sure to record in your field notes the use of an alternative area for capturing the waypoint. Heavy clouds and rain can also obstruct the ability of GPS units to receive satellite signals. Thus, waiting for obstructive weather to dissipate may be necessary when capturing waypoints. 8 Marking Waypoints After you have chosen a spot for capturing a waypoint and ensured a good signal from at least four satellites, you can mark the waypoint for the health facility. 1. Go to the Mark Waypoint screen by holding down the Enter/Rocker button until the screen appears (approximately 2 seconds) or go to the Main Menu and click on . 2. On the Mark Waypoint screen, rename the waypoint so that it matches the facility code used in the LIAT by: a. Highlighting the waypoint name (shown at right in yellow) and pressing the Enter/Rocker key. b. Using the alpha-numeric keypad to change the name of the waypoint so that it matches the unique identifier chosen for the health facility by the assessment organizers. 3. Click on Avg to save the new waypoint. Then stand in the same location and wait for the GPS unit to complete collecting the location of the GPS device. The GPS point has been collected once the device returns to the Main Menu screen. 9 10 Reviewing and Editing Waypoints To view and edit waypoints that have been logged: 1. Return to the Main Menu and choose Find. 2. On the Find screen, choose 3. Highlight a waypoint and click the Enter/Rocker button to view corresponding data. 4. Edit any of the waypoint information (e.g., name, marker) by highlighting it and clicking the Enter/Rocker key. . Additional Options In addition to editing waypoint information, three other options are available on the Waypoint screen: 1. Select Delete, and then click Yes to confirm the removal of a waypoint. 2. Select Map to display the waypoint on a map (the point will be shown at the center of the on- screen map). 3. Select Go To for a compass that will point you in the direction of the waypoint and provide its distance. 11 12 Downloading GPS Data to a Computer To download data from the GPS device to your computer for aggregation and analysis, you must first install the appropriate USB driver, which enables access to files and programs stored on external devices. You must also install TrackMaker software, which is used to upload and download routes, tracks, and waypoints between GPS devices and computers. Additionally, TrackMaker makes it possible to save data in the correct format (.kml) and export it to Google Earth for display. Install the correct USB driver and TrackMaker using the CD-ROMs provided with the GPS device or go to: USB driver—http://www8.garmin.com/support/download_details.jsp?id=591 TrackMaker—http://www.gpstm.com/downloadscontract.php Downloading Data 1. Plug the first GPS unit into the computer using the serial or USB cable. 2. Turn the GPS unit on. If prompted, set the GPS for indoor use. .3. Click on 4. Click on GPS from the menu bar and select Garmin to access the Garmin Interface screen. 5. Click on the Product ID button to show the GPS device’s specifications. If the specifications do not appear, check to see that the GPS unit is on and that the cable is attached correctly. Alternatively, look to see whether the USB radio button is filled in. If not, reinstall the USB drivers. 6. Click the Capture button. 7. Click the Waypoints button to download the waypoints from the GPS device. The black dialog box on the screen will show the number of waypoints that have been downloaded from the device. 13 8. Click the Exit button. At this point, the waypoints should appear on your screen similar to the example below. If they do not appear, click on the View tab and check the Waypoints selection. 9. Go to File in the menu bar, and select Save File. a. Navigate to the proper file location. b. Save as a GPS TrackMaker file (.gtm). Include the survey country, year, and starting and ending waypoint numbers in the file name (e.g., Nigeria_2005_1_50.gtm). c. Click Save. 10. Repeat this process for each GPS unit that contains waypoints for the survey. 14 Exporting Waypoints 1. Open the .gtm file you want to export. 2. Go to File in the menu bar, and select Save File As. a. Navigate to the proper file location. b. Save as a Google Earth File (.kml). Include the survey country, year, and starting and ending waypoint numbers in the file name (i.e. Nigeria_2005_1_50.kml) c. Click Save. 3. Open Google Earth (download Google Earth from http://earth.google.com/ if you haven’t done so already). 4. Choose FileOpen from the menu. 5. Navigate to your file and click Open. The data will then display on your screen. 15 16 References Garmin. 2002. eVenture Personal Navigator Owners Manual and Reference Guide. Olathe, KS: Garmin. ICF Macro. 2010. Geographic Positioning Satellite (GPS) Manual for Use with Demographic and Health Surveys. Calverton, MD: ICF Macro. 17 18 For more information, please visit deliver.jsi.com. USAID | DELIVER PROJECT John Snow, Inc. 1616 Fort Myer Drive, 11th Floor Arlington, VA 22209 USA Phone: 703-528-7474 Fax: 703-528-7480 Email: email@example.com Internet: deliver.jsi.com
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