DGPS Survey
A DGPS system is an improvement of the Global Positioning System to provide better location accuracy. Kongunadu Surveyor offers the best Global Positioning system survey in Coimbatore where the range varies from 15 meters nominal GPS accuracy to about 10 cm in case of the best implementations. A fixed position is used to adjust real-time GPS signals to exclude pseudo-range errors. The DGPS system is capable of enhancing the accuracy of GPS measurements as it duplicates the errors caused.
Our DGPS survey services in Coimbatore use a network of fixed ground-based reference stations to transmit the difference between the GPS satellite system and known fixed positions. The digital correction signal is broadcasted in the nearby vicinity by ground-based transmitters of a shorter range.
What is the need for DGPS?
By using the DGPS control survey, positional accuracy can be improved from around 1.5 m with standard GPS to around 40 cm with DGPS, without the need for post-processing. At Kongunadu Surveyor, the GPS measurements are normally stored in computer memory in the GPS receivers and are successively transmitted to a computer running the GPS post-processing software. The software calculates baselines using concurrent measurement data from two or more GPS receivers.
Inexactness in satellite clocks, imperfect orbits, the trip through the layers of the atmosphere, and many other sources add to the inaccuracies of GPS signals by the time they reach a receiver. These errors are adaptable, so the best alternative to correct is to monitor them. The best way to do this is by setting up a GPS receiver on a station by our DGPS surveyors in Coimbatore whose position is known as the base station.
The base station is at a known point, whether it is on a building permanently or it is a tripod-mounted base station. Since it is in a known position, it allows the base station to produce corrections. The constellation tells the base station that it is in a slightly different place, so corrections are sent to the rover at the unknown point.
This base station receiver’s computer can calculate its position from satellite data, compare that position with its actual known position, and find the difference. The resulting corrections can be communicated from the base to the rover.
The DGPS Survey of boundaries is most useful to calculate the difference between the real distance measurement and the theoretical distance.