Using Filtered and Semicontinuous High Rate GPS for Monitoring Deformations

Abstract

Multipath is a major sidereally-repeating error affecting precise GPS positioning and deformation monitoring. Because satellite-receiver geometry repeats almost exactly every sidereal day, filtering can reduce multipath in near-static situations. Here, we investigate how sidereal filtering can be used in a switched multi-antenna array system providing semicontinuous GPS data, which may be adopted in order to reduce hardware costs.Depending on the receiver's set-up, the optimum session switching interval is 119 seconds or a multiple thereof. This provides sufficient reliable epochs using a short switching interval, and is synchronized with the appropriate geometry repeat interval for sidereal filter application. The semi-continuous sidereally-filtered GPS technique is efficient in detecting horizontal and vertical displacements, surpassing 5 mm and 8 mm precision respectively per epoch in near-static environments with moderately high multipath. This provides the capability of monitoring deformations occurring at periods greater than double the switching interval, although it can also be used for monitoring rapid structural deformations despite data gaps which may affect temporal resolution. Consequently, this combined method presents an efficient, cost-effective and precise GPS technique.

Global Navigation Satellite System‐based positioning technology for structural health monitoring: a review

“…The other signal switch devices similar to GPS multi‐antenna switch were also designed by Forward et al and He et al The multi‐antenna GPS system can significantly reduce GPS hardware costs for monitoring deformations. This multi‐antenna technique is only suitable to the long‐term static displacement monitoring of engineering structures because the data of multi‐antenna GPS system are not collected continuously …”

“…This multi-antenna technique is only suitable to the long-term static displacement monitoring of engineering structures because the data of multi-antenna GPS system are not collected continuously. 92…”

Reduction of Kinematic Short Baseline Multipath Effects Based on Multipath Hemispherical Map

“…If the antennas keep static and the environment remains unchanged, the multipath effects of consecutive sidereal days are highly correlated due to the sidereal repeat period of Global Positioning System (GPS) constellation [11,12,13,14,15,16,17]. The SF approach for multipath mitigation has been implemented in precise point positioning [16,18,19], and was applied to natural hazard warning [19,20,21] and structural health monitoring [17,22,23]. However, such a temporal repeatability is no longer viable for a moving platform.…”

Ground Deformation Studies and Evacuation Behavior During Eruptions at Guatemalan Volcanoes

“…The first being single epoch ambiguity resolution, and second multipath error. Multipath error is a consequence of the reflection of the GPS signal from nearby surfaces and is commonly one of the most limiting factors in precise GPS positioning (Ragheb et al 2009).…”