Variable length LMS adaptive filter for pseudorange multipath mitigation based on SydNET stations

摘要

Multipath effects on pseudorange measurements even after antenna design improvements and signal processing are still significant, and can't be ignored in many cases. Data processing techniques to mitigate multipath effects, Least Mean Square (LMS) filters specifically, are investigated in this paper.rnSince the multipath effects repeat every sidereal day, if the receiver environment is unchanged, the strong correlation between two successive days' pseudo-range observations, which is assumed to be mostly due to multipath effects, can be extracted by an LMS filter. In addition, the frequency shifting characteristics of the two successive days' correlation vector demands an adaptive filter. In this paper the performance of two LMS adaptive filters, the standard LMS adaptive filter and the variable length LMS (VLLMS) adaptive filter, are investigated. This paper reports the results from an analysis of observation data from SydNET CORS receivers.