This article provides recommendations on drive testing of mobile global positioning system (GPS) receivers. A well-designed drive test can provide important information about the relative capabilities of receivers from different manufacturers and can be used to verify the system design. To achieve valid results, the GPS receivers must be tested at the same time and in the same conditions, against a control reference receiver which is the same in each test. The drive route should characterise the intended application and include a variety of vehicle environments, with a starting location where good GPS signal conditions exist so that the equipment can be set up and verified. Antenna placement is best on top of the vehicle. Data collected is compared to the reference data, including comparison of velocity and altitude profiles. Sources of error can be the rapidly changing view of the satellites, reflections of signals, the integral oscillator and heading accuracy. The author points out that no GPS receiver can provide accurate positioning in every location all the time. For the covering abstract see ITRD E118381.
Abstract