Empirical analysis of environmental effects on real time kinematics differential GNSS receiver

Abstract

Satellite navigation has been in use for the positioning for quite sometimes. Like all Electromagnetic signals, the GPS signals are also affected by the interferences. Usually the general purpose GPS receivers has the accuracy of 10 ∼ 20 meters. However, the evolution of Real Time Kinematics (RTK) resolved the problem to millimeter accuracy by employing the double differenced carrier phase measurements. RTK positioning is very popular because it provides a precise and efficient way of differential positioning. RTK technique is based on the ambiguity resolution, which is so far the most intricate part. Long initialization time and cycle slips during operation is the main drawback of this technique which increases under obstructive environmental conditions, like power outage due to tree cover and strong multipath in urban canyon. As RTK is a differential technique which uses a base station at a known location and moving rover. The distance between the rover and base station receivers directly affects the accuracy. However, at Zero Baseline which uses the same antenna for the base station and receiver, thus having same environmental effects, provides a trivial but the best possible scenario and all real life uses are more challenged than this. This paper discusses an empirical analysis of the technique during the high environmental effects on the system (Base + Rover) by employing a Zero Baseline condition. The result of the zero base line tests gives an upper bound to the accuracy of the system in any environment. To measure the accuracy, the setup was taken to the varying environmental conditions in the field and their outputs were analyzed using RTK technique.