Multipath detection with the combination of SNR measurements – Example from urban environment

Abstract

Abstract:Multipath is one of the most severe station-dependent error sources in both static and kinematic positioning. Relatively new and simple detection technique using the Signal-to-Noise (SNR) measurements on three frequencies will be presented based on idea of Strode and Groves. Exploitation of SNR measurements is benefi cial especially for their unambiguous character. Method is based on the fact that SNR values are closely linked with estimation of pseudo-ranges and phase measurements during signal correlation processing. Due to this connection, combination of SNR values can be used to detect anomalous behavior in received signal, however some kind of calibration in low multipath environment has to be done previously. In case of multipath, phase measurements on different frequencies will not be affected in the same manner. Specular multipath, e.g. from building wall introduces additional path delay which is interpreted differently on each of the used carrier, due to different wavelengths. Experimental results of multipath detection in urban environment will be presented. Originally proposed method is designed to work with three different frequencies in each epoch, thus only utilization of GPS Block II-F and Galileo satellites is possible. Simplifi cation of detection statistics to use only two frequencies is made and results using GPS and GLONASS systems are presented along with results obtained using original formula.

A high order statistics based multipath interference detection method

“…© 2021 The Authors. IET Communications published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology [16][17][18]. The multipath parameters estimation based method detects multipath interference by estimating the number, time delays, amplitudes and phase lags of paths.…”

“…Therefore, there is an urgent need for the detection of multipath interference. Some literatures have studied the problem of multipath interference detection, and the most commonly used methods can be divided into two types, the multipath parameters estimation based method [13][14][15] and the feature-based method [16][17][18]. The multipath parameters estimation based method detects multipath interference by estimating the number, time delays, amplitudes and phase lags of paths.…”

“…To ensure reliability, CNRs on three frequencies are used for detection. Špánik et al [17] adopted CNRs on two frequencies to detect multipath interference, which enables the applicability for GPS and GLONASS systems. Considering the multipath error in the pseudo range measurement of GNSS signal, Beitler et al [18] adopted the code-minus-carrier delta range (CMCD) feature, which means the difference of delta ranges derived by the code and the carrier.…”

Optimization Technique for Pseudorange Multipath Mitigation Using Different Signal Selection Methods

“…From a previous study, there are many mitigation techniques used to reduce the pseudorange multipath error. These techniques can be divided into three categories: antenna design (Groves et al, 2013), receiver-based correlator design (Matera el al., 2019;Sánchez et al, 2017), and post-processing technique (Hsu et al, 2016;Iwase et al, 2013;Lin et al, 2018;Matera et al, 2019;Sánchez et al, 2017;Špánik and Hefty, 2017;Suzuki, 2011;Suzuki and Kubo, 2015;Satirapod and Rizos, 2005;Dammalage et al, 2010). Without involving modification of the antenna used or the complexity of implementing the receiver's architecture, the post-processing technique is the optimum choice for work that does not require a high-precision solution.…”

Untitled

“…Pristop k zmanjšanju vpliva motečih signalov je zelo podoben problematiki sprejema odbitih signalov GNSS (angl. multipath) (Chang, 2011;Špánik in Hefty, 2017). V obeh primerih je cilj povečati razmerje med signalom in šumom (angl.…”