TESTING OF AN ACTIVE MULTIPLE REFERENCE STATION NETWORK FOR RTK POSITIONING

摘要

GPS Real-Time Kinematic positioning (RTK) is now increasingly used for many surveying and navigation applications on land, at sea and in the air. However, as the distance between a GPS user and his reference station increases, more decorrelated positioning errors limit the ability for RTK positioning. It is especially significant in the tropical area like Singapore where turbulent atmospheric conditions results in rapid changes with ionospheric and tropospheric errors over shorter distance. However, this constraint can be improved by using the multiple reference station network technique. Singapore Integrated Multiple Reference Station Network (SIMRSN) has been established to support fast-static and RTK positioning over large area. The objective of this paper is to evaluate the performance of RTK positioning using the corrections generated by SIMRSN. Real-time test results with virtual reference station (VRS) concept are presented to demonstrate the performance of RTK with the SIMRSN corrections at different position in Singapore. Compared with the known coordinates of the testing point, the accuracy of RTK positioning can be achieved at a few centimetres level in 3D-position. The time to fix ambiguity for RTK with the SIMRSN corrections is within 3 minutes at most time, often even within 80 seconds during these real-time tests.