Low cost GNSS instruments for monitoring applications

Abstract

Among several instruments and techniques that can be used for monitoring purposes, the GNSS technology is under fast evolution and provides a large choice of solutions. The best performances can be achieved by using double frequency geodetic receivers, capable to maintain high precisions even for wide scale monitoring. Nevertheless, in the recent years several interesting solutions were presented in the low-cost market. In this work, a monitoring system based on a couple of low cost GNSS receivers has been developed and tested on the field. The two receivers were positioned about 50 meters from each other and data were acquired at 1 Hz frequency. The position solutions were calculated both in post processing, through two different free and open-source software, and using the embedded RTK processor. The analysis aims to assess the capability of the system to perform the monitoring of slow displacements with the best possible precision. The precisions evidenced by the tests show that such low-cost instrumentation can be used for many monitoring purposes, especially considering the cost, which is about a tenth of the price for geodetic instruments.