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The Population Estimation Service is a Web-based service for
estimating population totals and related statistics within a
user-defined region. It enables users of a wide variety of map
clients and tools to quickly obtain estimates of the number of
people residing in specific areas without having to download and
analyze large amounts of spatial data. The service accepts polygons
that define areas of interest, then returns population totals, land
area, quality measures, and basic parametric statistics for the
requested polygons based on GPWv3.
To use the map below, pan (drag) or zoom (using the
toolbar) to an area of interest. Draw a polygon by clicking on the
map to define the outside of an area; double-click to complete the
polygon and submit the request. After the estimation is complete, a
table will display below the map with the population estimates and
statistics. Use the clear button to reset the map and draw another
polygon.
Service Features
The service is accessible through three standard protocols
used by many online map tools and clients: the Open Geospatial
Consortium (OGC) Web Processing Service (WPS) standard, a
Representational State Transfer (REST) interface, and a Simple
Object Access Protocol (SOAP) interface. Standards-based clients
such as uDig are able to
submit requests using the OGC WPS. Users of ArcGIS software from
ESRI can submit requests through SOAP. The REST interface is
intended for use with lightweight javascript clients.
- The parametric statistics returned for each supplied
polygon include the count (number of grid cells used in the
analysis), minimum population count, maximum population count,
range of population counts, mean population counts, and standard
deviation of population counts.
- Two measures of data quality are included in the service
results. The first measure reflects the precision of the input data
and the second indicates when the requested polygons are too small
in area compared with the underlying input data to produce reliable
population statistics.
Access
To access the Population Estimation Service, users need to
work with an online map client or Geographic Information System
(GIS) software package that supports spatial queries through one of
the three supported protocols. The service interfaces are available
at:
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