Evaluation of raw GNSS measurements collected from Android phones

• Main Author: Lin, Minyi
• Other Authors: Ling Keck Voon
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/163998
• Institution: Nanyang Technological University

In this dissertation, we used a data logger app developed by Google to collect the Global Navigation Satellite System (GNSS) raw measurements on an Android smartphone. Based on the raw GNSS measurement data collected, we classify and analyse the various types of information in the data logs, use the pseudorange observations at different time, and also the ephemeris to estimate the coordinates of position and corresponding velocity of the user in the dynamic and static tests. We compare the performance of two positioning algorithms, namely Weighted Least Square (WLS) and Moving Horizon Estimation (MHE). The position and trajectory given by the U-blox professional receiver are used as the ground truth for this comparison. The experiment results show that the position and trajectory estimated by the MHE are more accurate and have fewer Root-Mean-Square-Errors (RMSEs) than that of the WLS. Moreover, in the MHE algorithm, the range of referenced data within 5 to 8 seconds has a relatively good estimation performance in the dynamic test, while the performance becomes better with a more extensive range of referenced data in the static test.