WorldPop uses census data combined with GIS data (collaboarting with CIESIn in some instances) to create databases of population and country data. In its collaboration with UNFPA, high resolution satellite imagery is pooled with "bottom-up" data microcensus data collected in the field.
By collaborating across sectors WorldPop is able to combine satellite data, census data, and microcensus data to develop more robust population and settlement datasets. Data is then made available online via WorldPop for public to access and use.
The data made available by and to UNFPA through their collaboration with WorldPop has significant opportunities to improve public health, humanitarian and development outcomes. For instance, Nigeria's vaccination tracking system is built on this database.