The Calibration Method Study Based On Gps Vehicle Speed Observation System

With the increasingly severe form of road traffic safety, need establish safety monitoring system traceability calibration standard to measure speed, in order to reduce the traffic accident hidden trouble. Global positioning system, with its high speed measusing precision can be used as the speed of metrological standard device, the method can be used in other speed traceability standard. The main content of research is GPS device speed measurement standard of traceability.The main research contents include:Firstly, analyze the current domestic and foreign relevant GPS speed present status and progress of research, and introduce the global positioning system (GPS) and GPS speed principle.Secondly, put forward the GPS vehicle speed monitoring calibration system design. Experiments using IQ and AsteRxl receiver respectively for single speed experiment, get vehicle speed through the experiments. Analyze the random error of the vehicle speed from which collected information. The speed limit error of IQ receiver is 0.51 km/h.Through principle analysis and experiment, the results beyond the GPS measurement standard requirements; Throuh analyze the speed principle and experiment results, The limited speed error of AsteRxl receiver is 0.03km/h, satisfy the requirement of accuracy.Thirdly, analyze the GPS speed principle and the influence of the speed measusing precision.Forth, analyze the error sources. According to the national metrology specification JJF1059 "the expression of uncertainty in measurement ", evaluate the speed of GPS uncertainty. Through the evaluation results obtained, the method of AsteRxl receiver its expanded uncertainty is 0.12 km/h. The method of using GPS speed expanded uncertainty meets the expectations. The method can be used in other speed traceability.