Technology for Virtual Reference Station Service with Gradient Information of Spatially Correlated Errors

Traditional virtual reference station (VRS) service usually needs to change VRS frequently and depends on internet communication heavily in long-distance positioning or positioning throughout the area. In order to overcome these deficiencies, a technology was proposed to realize the differential data broadcast throughout the area. Based on the analysis of spatial error model, a computing model of VRS effective service distance was obtained, and the gradient information of spatially correlated errors was appended to differential data. Considering that conventional real-time kinematic (RTK) equipment is compatible with internet and radio, Internet, symbiotic radio and ultra-high frequency (UHF) radio were also combined to broadcast the data. The experimental results show that the virtual single base-station (VSBS) spacing or the distance of VRS changing can reach 5 km in mid-latitude plain areas while the impact of spatially correlated errors is set as 1 cm² in each coordinate component. A signal terminal with less than 2 W transmit power can broadcast the data to a distance of 27 km, which breaks the limits of data exchange needed in VRS service and several kilometers’ distance coverage of VSBS, and meets the application demands of high precision positioning in a distance of tens of kilometers with no internet access.