GNSS Multi-Frequency Direct Position Estimation Geometric Theory for Multipath Analysis

Jihong Huang, Rong Yang, and Xingqun Zhan

Peer Reviewed

Abstract:	In this article, we analyze the multipath characteristics of multi-frequency Direct Position Estimation (DPE) from a geometric perspective. Unlike traditional parameter estimation, the geometric analysis is more intuitive and clearly shows the mapping from the cross-ambiguity function (CAF) to Position, Velocity, and Time (PVT) solutions in multi-frequency DPE. The CAF in the navigation domain related to the PVT parameters and the multi-frequency combined correlation values are obtained. We then analyze the geometric features, including the slope and intercept of the multi-frequency correlation peak. Based on the multi-frequency geometric theory, we characterize the noise and multipath error of DPE. Field tests are conducted with GPS L1/L5 intermediate frequency (IF) data collected from road tests near the Lujiazui CBD area in Shanghai. The navigation domain correlation results show that, compared to GPS L1, GPS L5 has better anti-jamming capability due to its higher code rate. The multi-frequency geometric theory is also verified by the real data. Index Terms—GNSS, Multipath error, Geometrical propagation, Direct position estimation
Published in:	2025 IEEE/ION Position, Location and Navigation Symposium (PLANS) April 28 - 1, 2025 Salt Lake Marriott Downtown at City Creek Salt Lake City, UT
Pages:	602 - 609
Cite this article:	Huang, Jihong, Yang, Rong, Zhan, Xingqun, "GNSS Multi-Frequency Direct Position Estimation Geometric Theory for Multipath Analysis," 2025 IEEE/ION Position, Location and Navigation Symposium (PLANS), Salt Lake City, UT, April 2025, pp. 602-609.
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