Rooftop Sampling
A GPS-navigated household survey method that uses satellite building footprints as the sampling frame, no household list required. Developed by IDinsight, deployed with Frontline Workers as enumerators.
Five steps from satellite to doorstep.
Rooftop Sampling uses Google Open Buildings (1.8 billion structures) or Microsoft Building Footprints as a sampling frame, replacing the household lists that traditional surveys require. Enumerators navigate directly to GPS coordinates on their phone, no paper maps needed.
Download Building Data
Building footprints are downloaded from Google Open Buildings or Microsoft Building Footprints for the target geography. These satellite-derived datasets cover over 1.8 billion structures globally and require no in-country household list or census frame.
Filter Buildings
Buildings are filtered by confidence score and minimum roof size to eliminate small structures unlikely to be residential. The result is a clean sampling frame of plausible households, without a single field visit.
Sample Buildings
A random or systematic sample is drawn from the filtered frame. In the Nigeria pilot, each enumerator received 40 GPS points organized into 5 clusters of 8 buildings, clustered to minimize travel time while maintaining geographic spread.
Navigate to GPS Coordinates
Enumerators navigate to sampled GPS points using their phone. In the Nigeria pilot, 80% arrived within 15m of the target building, and 98% of pins led to inhabited homes.
Survey the Household
At the doorstep, enumerators conduct the household survey. In the pilot, Frontline Workers with no prior survey experience served as enumerators, receiving GPS navigation training and supervision. The survey captured vaccination coverage, child health status, and other program indicators.
Nigeria Pilot
3 States, 996 Households
The pilot covered 5 wards across Sokoto, Gombe, and Borno states, with approximately 200 households per ward, 1,846 children under five enumerated. Frontline Workers handled all fieldwork as enumerators with no prior survey experience.
Need to know what actually happened in the field?
Rooftop Sampling provides a satellite-derived, GPS-navigated alternative to traditional household surveys: no household list required, Frontline Workers as enumerators. Reach out to explore a coverage validation study.
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