Efficiency of carrier-phase integer ambiguity resolution for precise GPS positioning in noisy environments |
| |
Authors: | Liqiang Zhu Ying-Cheng Lai Mayur Shah Sultan Mahmood |
| |
Institution: | (1) School of Mechanical, Electronic, and Control Engineering, Beijing Jiaotong University, Beijing, 100044, China;(2) Department of Electrical Engineering, Arizona State University, Tempe, AZ 85287, USA;(3) Qualcomm Inc., 2581 Junction Ave., San Jose, CA 95134, USA;(4) Sverdrup Technology Inc., Eglin AFB, FL 32542, USA |
| |
Abstract: | Precise GPS positioning relies on tracking the carrier-phase. The fractional part of carrier-phase can be measured directly
using a standard phase-locked loop, but the integer part is ambiguous and the ambiguity must be resolved based on sequential
carrier-phase measurements to ensure the required positioning precision. In the presence of large phase-measurement noise,
as can be expected in a jamming environment for example, the amount of data required to resolve the integer ambiguity can
be large, which requires a long time for any generic integer parameter estimation algorithm to converge. A key question of
interest in significant applications of GPS where fast and accurate positioning is desired is then how the convergence time
depends on the noise amplitude. Here we address this question by investigating integer least-sqaures estimation algorithms.
Our theoretical derivation and numerical experiments indicate that the convergence time increases linearly with the noise
variance, suggesting a less stringent requirement for the convergence time than intuitively expected, even in a jamming environment
where the phase noise amplitude is large. This finding can be useful for practical design of GPS-based systems in a jamming
environment, for which the ambiguity resolution time for precise positioning may be critical. |
| |
Keywords: | Integer ambiguity resolution Integer least squares Precise GPS positioning Noise Jamming |
本文献已被 SpringerLink 等数据库收录! |
|