An online quality control system for GPS stations used for geodetic surveillance

The NeVoCGPS network consists of 30 GPS stations that implement a geodetic surveillance system of the volcanic area surrounding the city of Naples, in the south of Italy. Being deployed over a densely urbanized area, the GPS network is subject to many sources of potential interference, which can make some station unavailable. On the basis of a new experimental campaign and of the analysis of past recorded data, the authors have recently proposed the use of SNR, which is by default calculated by receivers, as a key parameter for the diagnostic of the state of health of GPS stations. The paper presents an efficient online system for monitoring the state of health of GPS stations. The goal of the system is to continuously provide the operators with information on the quality and the trustworthiness of the data gathered by the GPS stations, trigger proper maintenance actions, before an eventual problem arises, and ultimately reduce the unavailability of the stations.