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Lookup NU author(s): Ahmed Ragheb, Professor Stuart Edwards, Professor Peter ClarkeORCiD
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 multiantenna array system providing semicontinuous GPS data, which may be adopted in order to reduce hardware costs. Depending on the receiver's setup, the optimum session switching interval is 119 s 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 semicontinuous sidereally filtered GPS technique is efficient in detecting horizontal and vertical displacements, surpassing 5 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.
Author(s): Ragheb AE, Edwards SJ, Clarke PJ
Publication type: Article
Publication status: Published
Journal: Journal of Surveying Engineering
Year: 2010
Volume: 136
Issue: 2
Pages: 72-79
Date deposited: 17/09/2010
ISSN (print): 0733-9453
ISSN (electronic): 1943-5428
Publisher: American Society of Civil Engineers
URL: http://dx.doi.org/10.1061/(ASCE)SU.1943-5428.0000016
DOI: 10.1061/(ASCE)SU.1943-5428.0000016
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