Feasibility of displacement monitoring using low-cost GPS receivers

SUMMARY Many of the available SHM approaches neither readily support displacement monitoring nor work in concert with one another to take advantage of displacement-based SHM for various long-period structures. Although survey-quality GPS technology offers the possibility of measuring such displacements with sub-centimeter precision, the associated cost is too high to allow for routine deployment. Low-cost GPS chips commonly found in mobile phones and automobile navigation equipment are attractive in terms of size, cost, and power consumption; however, the displacement accuracy of these GPS chips is on the order of several meters, which is insufficient for SHM applications. Inspired by sensory information processing strategies of weakly electric fish, this paper investigates the potential for using dense arrays of relatively low-precision GPS sensors to achieve high-precision displacement estimates. Results show that dynamic response resolution as low as 20-30 cm can be achieved and that the resolution improves with the number of sensors used.