High Precision Kinematic Positioning Using Single Dual-frequency Gps Receiver

Currently, high precision kinematic GPS positioning with centimetre level accuracy can only be carried out using differential GPS (DGPS) positioning techniques which require the deployment of base receiver stations. The requirement to deploy base receiver stations, however, spatially limits the operating range of the rover receiver to about 20 km from the base stations. As a result, it not only increases the operational costs of equipment and human resources but also significantly increases the logistical complexity for many applications such as land geodetic surveying and airborne geo-referencing and mapping. With the increased availability of precise GPS satellite orbit and clock data in real-time from the International GPS Service (IGS) and many other organizations, high precision kinematic positioning at centimetre to decimetre level is now possible using a single GPS receiver. Presented in this paper are the methods and algorithms that have been developed at the University of Calgary for high precision kinematic positioning using a single dual-frequency GPS receiver. Different from the conventional DGPS approach, the new system does not need a base station since the position determination is based on the processing of un-differenced GPS code and carrier phase observations. This eliminates the range limitation related to the conventional methods, resulting in instant advantages in field operations. A software system developed at the University of Calgary will also be described along with numerical results to demonstrate the obtainable positioning accuracy and its potential for various applications.