Session B1b: Precise GNSS Positioning and Applications

Analysis of PPP-AR Using Real-Time Product in Suburban Environment
Zheng-Xin Lin, Shau-Shiun Jan, Department of Aeronautics and Astronautics, National Cheng Kung University
Location: Beacon A
Date/Time: Tuesday, Jan. 23, 4:46 p.m.

Peer Reviewed

This study aimed to analyze the performance of precise point positioning with ambiguity resolution (PPP-AR) in a dynamic suburban environment. The phase biases of the satellites can be reduced using real-time observable-specific signal bias (OSB) products provided by Centre National d'Études Spatiales (CNES). Moreover, by using OSB products with the between-satellite single-difference (SD) approach, the phase biases of the receiver can be reduced, thereby recovering the integer property of wide-lane (WL) and narrow-lane (NL) ambiguities. Float WL ambiguities can be estimated through the Hatch–Melbourne–Wübbena linear combination, and SD WL ambiguities can be rounded to integers if the fractional cycle is small enough. Integer SD NL ambiguities can be determined using the least-squares ambiguity decorrelation adjustment (LAMBDA) method and validated using the ratio test and lower bound success rate. After SD NL ambiguities are fixed, SD ionosphere-free ambiguities can be fixed and the states in the extended Kalman filter (EKF) can be reduced to have a fixed solution. Dynamic experiments were conducted in a suburban environment, and in the experiments, NovAtel PwrPak 7 and LN200C were used as reference systems. Herein, the time to fix ambiguity, fixed rate, and positioning performance results of PPP-AR were compared with those of PPP in a suburban environment; this is the main contribution of our study. The root mean square error values in the east, north, and upward directions were 0.4051, 0.1335, and 0.3462 m, respectively. The positioning results of PPP-AR improved by 10% compared with those of PPP.