Quality Control Of ARSNet/VENUS Network RTK Location Service

Since the birth of the 90 s last century,the network RTK has attracted much attention with its advantages of high precision,wide coverage and all-weather real-time dynamic positioning etc.With the development of navigation and positioning,computer and communication technology,network RTK technology is constantly improvement,The network RTK Location service has a more extensive demand,Lane level vehicle navigation,unmanned,refined agriculture,UAV and other industries require higher reliability of network RTK Location service.However,at present,there are still a lot of problems in the network RTK system service.Under the current technology,there will inevitably be abnormal solutions when calculating the ambiguity between RTK stations,especially the low altitude satellite,which seriously affects the accuracy of the correction,reduce the reliability of the rover coordinate solution results.But now,there is very little research on how to detect and repair when ambiguity resolution abnormity.Therefore,starting from detection the ambiguity resolution abnormity between RTK stations To control ARSNet/VENUS(Augmentation Reference Station/Vrs-Enhanced Network Utility Solution)network RTK Location service quality will be the focus of this paper.Under this background,this paper introduces the factors that influence the Location service quality of network RTK in detail,throught analyzes the problems of the ARSNet/VENUS network RTK system ambiguity solution between the stations,and combining with the gross error detection theory,proposes a quality control method for the carrier phase data calculation of the network RTK reference station,Integrated the method into ARSNet/VENUS,post-processing and real-time testing experiments are carried out to verify the reliability of the method.The main contents and work involved in this article are as follows:1.Introduce the inter station ambiguity resolution strategy,distance correlation error and interpolation model which affect the quality of network RTK Location service in detail,and summarize the problem of inter station ambiguity resolution strategy,the processing mode of distance correlation error in the network RTK and the applicability of the interpolation model.2.Analysis of L1 frequency ionosphere delay and altitude angle time series on the CHDU_RENS baseline of Sichuan CORS after initialization of the baseline ambiguity.Knowing that the station ambiguity resolution will be abnormal and most of them are below the 25 degree altitude satellites,the abnormal duration can be up to several minutes,and the abnormal cycles can reach two cycles.Inevitably,single epoch multiple satellite ambiguity resolution anomalies occur.In order to solve the problem of ambiguity resolution between stations,a quality control method for carrier phase data calculation of network RTK reference station is proposed,and the ionosphere-free model,data snooping method,QUAD method theoretical formula used in this method are introduced in detail.And it is verified by experiments that the method uses data detection method to detect the gross error of the ionosphere-free observation equation composed of satellite data,and then adds the satellite data through gross error detection to the moving window.Can reliably make the satellite data in the moving window are not gross error satellite data.3.The network RTK reference station carrier phase data solution quality control method was integrated in ARSNet/VENUS to perform post-processing and real-time test experiments to verify its reliability,And whether to effectively control the quality of location serviece.In the post-processing,CHDU-RENS(48.8 km)?RENS-QLAI(78.6 km)?ZHJI-RENS(98.9 km)three baseline data in Sichuan CORS network were used to design different baseline length experiments,and it was concluded that the anomaly probability of network ambiguity resolution between stations was positively correlated with the baseline length.For 100 km baseline,the anomaly probability of network ambiguity resolution can up to 9%,The BDS C04 and C05 satellites have more anomaly epochs,In most cases,the method can detect the abnormal satellite reliably,regardless of the single or multiple satellite ambiguity resolution in the epoch,and repair the integer ambiguity of the satellite by judging the pseudo true error value.In real-time testing,by analyzing system output ionosphere delay,quasi true error and coordinate time series,it can be found that,First,1 satellite 1 cycle ambiguity resolution anomalies can cause single-GPS receiver plane coordinate deviation value of 3cm jump,height direction is 4cm,1 satellite 2 cycles ambiguity resolution anomalies can cause single-GPS receiver plane coordinate deviation value of 9cm jump.And,it is uncertain that which direction of coordinate deviation value coordinate affected Most when the ambiguity resolution anomaly.Second,The network RTK reference station carrier phase data solution quality control method is reliable in real-time testing,and can effectively solve the problem of coordinate deviation jump of rover station,improves the ARSNet/VENUS network RTK Location service quality.