附有空间误差梯度信息的虚拟基准站服务技术

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

为了克服传统虚拟基准站服务技术在长距离定位服务和全域范围服务中存在频繁换站,以及严重依赖互联网通讯的不足,利用现有RTK(real-time kinematic)设备兼容互联网模式和电台模式的基本条件,通过空间误差模型分析,将空间误差梯度信息附加在差分服务数据中,并结合互联网、共生调频数字广播和特高频无线电广播等技术手段,实现了面向全域范围的差分数据播发;同时,给出了传统虚拟基准站有效服务距离的计算模型.实测结果显示:设定空间误差修正质量对流动站坐标各方向精度影响小于1 cm2的情况下,中纬度平原地区虚拟单基站网络站间距或者传统虚拟基准站服务的换站距离可以达到5 km;利用单个功率低于2 W的信号终端实现了27 km的远距离数据播发,突破了传统虚拟基准站服务需要数据交互且单个虚拟基准站有效服务距离只有几公里的限制,可满足包含数十公里通讯盲区的全域高精度定位应用需求.

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.