The Evolution of SAP: From R/1 to Intelligent Enterprise

DGPS Survey

A  Differential Global Positioning System (DGPS) is an Enhancement to the Global Positioning system (GPS) which provides improved location accuracy. In the range of accuracy, from the 15- meter nominal GPS accuracy to about 1-3 cm in the case of best implementations.

How does DGPS Survey Work?

DGPS is essentially a system to provide positional corrections to GPS Signals. DGPS uses a fixed, known position to adjust real time GPS signals to eliminate pseudorange errors. DGPS has no effect on results that are based on speed data, such as brake stop results. Each DGPS uses a network of fixed ground- based reference stations to broadcast the difference between the positions indicated by the GPS satellite system and known fixed positions. These stations broadcast the difference between the measured satellite pseudoranges and actual (internally computed) pseudoranges, and receiver stations may correct their pseudoranges by the same amount. The digital correction signal is typically broadcast locally over ground-based transmitters of shorter range.

Operation:

A reference station calculates differential collections for its own location and time. Users may be up to 200 nautical miles (370 km) from the station, however, and some of the compensated errors vary with space. Specially, satellite ephemeris errors and those introduced by ionospheric and tropospheric distortions. For this reason, the accuracy of DGPS decreases with distance from the reference station. The problem can be aggravated if the user and the station lack “inter visibility” when they are unable to see the same satellities.

Variations:

DGPS can refer to any type of Ground-Based Augmentation system (GBAS). There are many operational systems in use throughout the world, according to the US Coast Guard, 47 countries operate systems similar to the US NDGPS (National Differential Global Positioning System).

Plot Monitor - Secure Your Property !

Plot Monitor provides service to monitor Plot/Sites. and provides apartment related services including Khata transfer, property tax payments and other value added services. Plot Monitor will provide a report on various parameters such as Encroachment, Illegal activity and property status along with recent photographs. Plot Monitor uses DGPS Survey for measuring Plots.