The Antenna Up-To-Down Gain Ratio Design for Multipath Mitigation of GNSS Reference Station Receivers

Abstract

Multipath is one of the dominant causes of error in pseudorange observations for GNSS (Global Navigation Satellite Systems) reference station receivers whose multipath mitigation performances are related to four factors: the receiving scenario, the antenna height, the antenna gain pattern (up-to-down gain ratio) and the receiver-internal multipath mitigation technique. However, quantitative analysis of relations between the code tracking multipath error and the antenna parameters (including the height and up-to-down ration) is still absent. With two assumptions that the reflectors in the typical GNSS reference station receiving scenario are horizontal planes and the receiver-internal technique is Double-delta technique, the paper derives the functional relations between the code tracking multipath error and the antenna parameters. Based on these functions, this paper proposes theoretical formulae for the antenna up-to-down gain ratio design given the upper limit of the code tracking multipath error and antenna height. The quantitative and exercisable results presented in this paper are significant and instructive in the multipath-rejecting antenna design for GNSS reference station receivers.