160 likes | 292 Views
Multiple Indicator Cluster Surveys Survey Design Workshop. Using GPS to collect cluster locations. What is GPS. GPS is a satellite-based navigation system
E N D
Multiple Indicator Cluster SurveysSurvey Design Workshop Using GPS to collect cluster locations MICS4 Survey Design Workshop
What is GPS • GPS is a satellite-based navigation system • A GPS unit determines its position using satellites that orbit the earth. Each satellite’s position, as well as the current time, is transmitted via radio signals. The GPS unit receives these signals and uses them to calculate its position in terms of latitude, longitude, and altitude • There is a variety of GPS brands and models • Recommended model for use in MICS surveys is GARMIN ETREX GPS MICS4 Survey Design Workshop
Why use GPS to collect cluster locations • Permits linking of additional data to MICS data through geographic links • E.g. Census data, facility data, other geo-located data • Permits geographic grouping of data beyond region • E.g. Climactic zones, agricultural zones, etc. • Permits mapping of sample clusters • E.g. with DevInfo MICS4 Survey Design Workshop
Examples of what GPS data can bring to MICS Source: DHS studies MICS4 Survey Design Workshop
Decision Process for GPS Data Collection Method • Using pre-existing GPS data • Ex. using Geo-referenced Census • GPS coordinates can be acquired before the survey or listing (after EA selection) • Collection of GPS during listing • If not talk to the survey manager to discuss possible options (strong recommendation to collect GPS data during listing activities) MICS4 Survey Design Workshop
GPS Collection Process • The GPS collection teams collect one waypoint (location) for each assigned cluster • The waypoints are captured as close to the geographic center of the cluster as possible • Saved information are waypoint name (cluster number), latitude, longitude, and altitude to the GPS unit • These information should also be written down on GPS form that will serve as a paper back-up if any digital data in the GPS unit is lost or corrupted MICS4 Survey Design Workshop
GPS Collection Teams • GPS data collection may be incorporated into different phases of survey: • If the GPS units are used to update the sample frame, then listing teams are responsible for collecting the GPS data • GPS data collection may also take place during interviews, in which case one person on a team may be responsible for collecting the GPS waypoints MICS4 Survey Design Workshop
How to use GPS • Finding a “Good” Location to Collect a GPS Waypoint • Activate GPS • Identify and mark location (“waypoint”) • Record location on form MICS4 Survey Design Workshop
1. Finding a “Good” Location to Collect a GPS Waypoint • Find a place with a clear unobstructed view of the sky • First Choice: Geographic center of the populated settlement area of the cluster • Second Choice: Open area near the center, or on top of a building in the center MICS4 Survey Design Workshop
2. Activate Garmin • Turn on the Garmin. Once it has locked into enough satellites then press the Page button until you reach the MENU screen and select MARK. MICS4 Survey Design Workshop
3. Assign Cluster Number • Highlight the Waypoint ID • Enter in the Cluster Number Waypoint ID Coordinate MICS4 Survey Design Workshop
4. Complete GPS Form • Complete the GPS Form • Highlight OK and click Enter MICS4 Survey Design Workshop
Example of Log Sheet MICS4 Survey Design Workshop
Post Field GPS data checking and cleaning • When GPS data return from field work, the GPS Data Collection Coordinator checks that the GPS data are correct • S/he uses GPS TrackMaker1, a free geographic information system, to plot the GPS points and check for common errors The GPS TrackMaker® program for Windows® 98SE/2000/ME/XP/Vista allows bi-directional datacommunications between GPS receivers and your computer, including full data editing and storage options MICS4 Survey Design Workshop
Common errors in the GPS data • Duplicate or Paired Points • Missing Data • Administrative Mismatches • Hand-Entry Typos MICS4 Survey Design Workshop
With thanks to MICS4 Survey Design Workshop