Development of a platform for evaluating a GNSS positioning system

Sammanfattning: The project aims to develop a platform for the demonstration and evaluation of Global Navigation Satellite Systems (GNSSs). The GNSS receivers used in the project are two uBlox NEO-M8P modules, one of which is used as a reference receiver in a differential GNSS setup. The entire platform has been implemented and consists of a network-controlled car (NetCar) which has a GNSS receiver and a 4G module on it, a separate reference GNSS receiver, a computer hosting a control interface for controlling the NetCar and a relay server for relaying data between the control interface and the NetCar. The platform has been tested for evaluating the GNSS. The performance was evaluated in terms of the time to first fix (TTFF), stationary positioning accuracy and tracking accuracy which includes qualitative evaluation of accuracy, statistical evaluation of accuracy and evaluation of absolute accuracy after moving. The test results show that the platform performed well for the demonstration and evaluation of the GNSS. The evaluation results show that the TTFF for the uBlox NEO-M8P used in the project averaged 24.2 s with a worst case of 33 s. The stationary positioning accuracy was found to drift in the order of tens of centimeters when using differential GNSS in RTK float mode and in the order of centimeters in RTK fixed mode. The relative trackingaccuracy between points during either RTK mode was found to be on the order of centimeters while the absolute accuracy was found to be drifting, probably due to the reference receiver position being acquired through self-survey. The current project can be extended further by including automatic navigation, sensor fusion, pathfinding and the like.