Live Satellite Based Requirements Evaluation for Maritime DGPS Reference Stations

Abstract

The existing requirements testing for the maritime DGPS reference stations is divided into two testing methods such as live satellite testing and simulator testing, where the live satellite testing checks only the proper operation. Simulator testing, on the other hand, is able to check the accuracy of raw measurements, pseudorange corrections, range rate corrections, user differential range error, and corrected position error. However the existing requirements testing is simple test methodology guideline and furthermore simulator testing is not a testing method reflected in the realistic environment. For this reason, this paper deals with the requirements evaluation method to be applied to effectively assessing the maritime DGPS reference stations. Firstly, in order to extract the requirements for maritime DGPS, this paper carries out a study to analyze the standards recently suggested by RTCM. And a live satellite based requirements evaluation method is proposed to achieve the reasonable assessment results from the standpoint of the extracted requirements for maritime navigation. It is presented that the proposed requirements evaluation method using international GNSS service data can be applied to the accurate and more realistic testing in contrast with the existing testing using GPS simulator and make up for the weak points of the existing testing using live GPS satellite. Finally this paper shows the evaluation results of off-the-shelf maritime DGPS reference station and discusses the validity of the proposed requirements evaluation method.