Study On Algorithm Of VRS Corrections And Precision Analysis

This paper generated correction error of VRS positioning process and precisionanalysis,then it introduced several normal space interpolation models.It studied on the methodsof reducing the multipath errors, measurement noise, receiver antenna carrier phase,which wereerrors related non spatial source, and the track error, ionospheric delay error, troposphere delayerror, three kinds of spatial correlation of error source corrections generation algorithm. Themain research contents and innovations are as follows:1、It described the main four kinds of space interpolation models in detail in the lastdecade,including Linear Combination Model(LCM)、Lower-Order Surface Model(LSM)、Distance-based Linear Interpolation Model(DIM)、 andLinear Interpolation Model(LIM)，besides,the purpose and character of each model for application were summarized.2、It summarized the methods of weakening three non spatial related errors:multipatherrors, measurement noise, center deviationof receiver antenna phase.3、It analysised the lack of conventional interpolation methods for track error correctionand introduced ARS/VRS correction computation models.At last analysis and summary weremade based on theory.4、Study on generation algorithm of ionospheric delay corrections were made.Therelationship between the ionospheric double difference residuals and baseline length and satelliteelevation angle were analyzed.Several conventional spatial interpolation models were applied toionospheric corrections calculation. The experimental results of the model were compared,andget the best model.5、It studied on the influence the MSTIDs had on the positioning of CORS network withmiddle or large scale,and put forward a kind of ionospheric delay prediction model withadditional temporal information,which was verified and analysised by the experimental data. Theresult showed that:,by comparing forecast model with the conventional model, the maximum ofthe ionospheric delay correction accuracy can be increased from0.2m to0.05m in the activeperiod of MSTIDs, which greatly reduced the effect of MSTIDs. It also studied on the influencethe length of prediction cycle had on the correction accuracy.It showed that:for CORS networkwhich have the scale of largeer than60km, the prediction model with90s prediction cycle canmaked the correction precision be increased from0.05~0.07m to about0.02m.6、This paper made a study on the generation algorithm for tropospheric delaycorrection.Besides,the relations between double difference residuals,length of baseline, stationelevation difference and satellite elevation angle were analyzed.Based on experimentaldata,several conventional spatial interpolation models were applied to the generation of tropospheric corrections.Finally, the results were compared.7、Interpolation model deviation caused by station elevation difference was experimentaland analyzed.As a result,it presented tropospheric delay elevation deviation correction model,based on the conventional space Interpolation model.At last, The study on feasibility was madecombining with the experimental data. The result showed that: for the target satellite whoseelevation angle was greater than25degrees, the interpolation accuracy can be maintained within7~8cm when the elevation difference between mobile station and reference station was close to800m, and the accuracy of this model was greater than LIM model about1~2cm. It canaccurately calculated the flow station of flow layer delay double difference, and was practicablein application.