Trimble's Rtk And Dgps Solutions In Comparison With Precise Point Positioning

Abstract

Differential GPS (DGPS) and Real-Time-Kinematic (RTK) solutions are widely accepted methods for accurate positioning and navigation. Initially these methods were based on single reference stations. A big breakthrough in performance and accuracy was achieved by the introduction of network solutions. Today, the use of the Virtual Reference Station method is a standard technology applied in a large number of regional RTK networks all over the world, to provide a positioning service with centimetre accuracy. DGPS techniques are used for marine, airborne and land applications and provide accuracies in the several decimetre range. The DGPS and RTK methods are based on regional reference station networks or nearby single stations. In contrast, the Precise Point Positioning (PPP) method is providing position accuracy of several centimetres to decimetres based on a globall distributed tracking network. Precise satellite orbit and clock information is derived from the network processing. The achievable accuracy with PPP is impressive, but this method suffers from long convergence times of the order of more than 20-30 min to achieve acceptable accuracies and therefore might not be the method of choice for all applications. This paper describes the current state-of-the-art in RTK and DGPS technology and compares it with the performance of PPP applications today. Performance numbers are presented for various baseline lengths and networks including accuracy, convergence, and reliability. © Springer-Verlag Berlin Heidelberg 2009.