Analysis of the application of GPS navigation receiver in the static relative positioning of short baseline

Abstract

The conventional use of a GPS navigation receiver normally led to positions with metric accuracy, where the receiver makes use of C/A code pseudorange to realize the absolute positioning. In this case however, the GPS receiver does not store information from pseudorange and L1 carrier frequency, preventing the post-processing use of more precise positioning methods, such those of relative positioning. This paper presents a prototype able to collect and store the pseudorange on the L1 frequencies and the L1 carrier signal received by a GPS navigation receiver. The prototype is a low-cost alternative to the GPS positioning thanks the way it is designed. In it the computer applications after data acquisition are free and used to extract the information that came from the GPS satellites signals, storing them in a digital file. This file is processed in another free of charge application using RINEX format that permits to end the processing of data using the relative positioning method. The results of static relative positioning with short baselines using those data shows decimetric and centimetric quality when compared to those came from a topographic receiver and a geodesic mark with known coordinates. As a base station of relative positioning was used POAL station of RBMC (Brazilian Network of Continuous Monitoring), whose data are available free of charge by the IBGE (Brazilian Institute of Geography and Statistic).

Key words: GPS, navigation receiver, relative positioning.