摘要

At least two simultaneously operating receivers are required for differential global navigation satellite system (GNSS) positioning. In this mode, the systematic errors between stations can be estimated or reduced in order to achieve much higher accuracy. Precise point positioning (PPP) is a rather new category. PPP is a combination of the original absolute positioning concept and differential positioning techniques. In PPP we use observation data of a single receiver and additional information on individual GNSS errors derived from a GNSS network, usually from ground based augmentation systems (GBAS). GBAS systems can be divided by the area of operation into global, continental, national or regional ground support systems (e.g. ASG-EUPOS, CORS, SAPOS, SWEPOS). GBAS systems allow users with a single receiver to position in differential mode based on observations from the reference stations. This paper presents an analysis of the position determination accuracy using single receiver GNSS measurements conducted under conditions of limited satellite availability and processed using various types of GNSS services. The PPP-CSRS service was chosen as an example of a PPP service. For differential processing mode, the ASG-EUPOS service was selected. The analysis was based on four days of data from three GNSS stations. The PPP-CSRS results show that horizontal accuracies of similar to 5 cm and vertical accuracies of 10 cm are achievable provided 0.5 h of open sky and low multipath dual frequency GNSS data. Accuracy clearly decreases for points measured under conditions of limited satellite availability. Analogous ASG-EUPOS service accuracies are noticeably better.

  • 出版日期2014-7