High-precision application of GPS in the field of real-time equipment positioning

摘要

In the frame of its research concerning real-time positioning and control of road construction equipment, the Inboratoire Central des Ponts et Chaussees, has carried out in l996 a study to know more about the actual vertical accuracy that a real-time kinematic (RTK) global positioning system (GPS) sensor could reach, under work site conditions. This study has widely used the dedicated testing facility called SESSYL, built to perform high-accuracy and real-time evaluation tests on positioning systems. It has been performed in collaboration with the French road contractor COLAS and the Ecole Superieure des Geometres et Topgraphes (ESGT). First, there is the proposed adapted geodetic transformation procedure, compatible with the high accuracy requirements. Then, the main results of a special SESSYL tests program are presented, where the impacts of several influencing parameters on the vertical accuracy have been carefully examined. The core part of the paper is the analysis of the typical RTK GPS set of data, from which we have tried to extract two different components: a high-frequency noise, rather easy to filter, and a low-frequency bias. This bias, given its good repeatability, can be modelled and used in prediction to improve in real-time the raw accuracy of the data As a full-scale validation of our study, a site experiment is finally described, choed out this time on a real piece of equipment (an asphalt paver) during real roadwork.