Dynamic performance of global positioning system velocity sensor for extremely accurate positioning

The aim of this research was to establish an inexpensive and extremely accurate positioning system. This report focuses on a global positioning system (GPS) velocity sensor, which consists of a low-cost single-frequency GPS receiver and a single-board computer. Its dynamic performance was confirmed and the possibility of using it for positioning is discussed through fixture and on-vehicle tests. The GPS velocity sensor measured velocity accurately. Velocity was measured more accurately with the GPS velocity sensor than with real-time kinematic GPS throughout the fixture and on-vehicle tests. More than 90% of the error in speed was less than 0.05 m/s according to the fixture test. Also, more than 70% of the error was less than 2.87°. It was also possible to determine position by integrating velocity from the GPS velocity sensor. Although accumulating and irregular errors were observed, the accuracy of positioning was higher than with differential GPS after irregular errors were compensated for. Problems for further study to reduce error are how to cancel out accumulated errors and how to initially determine the absolute position.