Are there surveyors in the house? Let us share experiences, collaborate, and share information.

Any links to DGPS service providers in Nigeria yet? This is an area that is 'begging' for development.

Surveying with GPS

Overview:

Initially developed for military use, GPS is now part of everyday life; used in mobile phones, in-car navigation and search and rescue equipment to mention just a few. But there is a wide variety of equipment and techniques that can be used for surveying.
This web site provided by the Smithsonian National Air and Space Museum gives more detail http://airandspace.si.edu/exhibitions/gps/
GPS was rapidly adapted for surveying, as it can give a position (Latitude, Longitude and Height) directly, without the need to measure angles and distances between intermediate points. Survey control could now be established almost anywhere and it was only necessary to have a clear view of the sky so the signal from the GPS satellites could be received clearly.
GPS is similar in some ways to the Trilateration and EDM except that the known positions are now the GPS satellites (and their orbits) 20,000 km in space. The equipment and calculations are extremely complex, but for the user the process is generally very simple.
In the commonly available receivers, the GPS receiver almost instantly works out its position (Latitude, Longitude and Height) with an uncertainty of a few metres, from the data broadcast by the satellites. This data includes a description of the satellites changing position (its orbit) and the time the data was transmitted.

Surveyors and map makers use GPS for precision positioning. GPS is often used to map the location of such facilities as telephone poles, sewer lines, and fire hydrants. Surveyors use GPS to map construction sites and property lines. Forestry, mineral exploration, and wildlife habitat management all use GPS to precisely define positions of important assets and to identify changes.

During data collection, GPS points can be assigned codes to identify them as roads, streams, or other objects. These data can then be compared and analyzed in computer programs called Geographic Information Systems (GIS).