| As BDS(Beidou satellite navigation System)formally provides regional service and global network construction,and BDS is the only satellite system with three-frequency signals in all constellations,the global navigation satellite systems enter the era of multiple constellation multiple-frequency fusion positioning.GNSS(Global navigation Satellite System)multi-system fusion will help improve positioning accuracy,reliability,and high visibility,complex environment availability.Multi-frequency observation combination has the characteristic of fast fixed ambiguity,and how to make full use of BDS three-frequency observation value is important for popularizing BDS application.GNSS single epoch solution without cycle slip detection and repair,can be lost in the satellite fast initialization of the lock,even in a bad environment is observed under harsh conditions,its availability is higher than that of multi-epoch data,to achieve efficient use of GNSS observation data.In view of this,this article has carried on the research to the above question,the main problem and the result are as follows:1.On the basis of the introduction of the pathological principle and the method of overcoming morbid disease,based on the condition-number method,the morbid nature of the dual-frequency and dual-band wide lane carrier-wave differential equation is analyzed,and it is shown that the pathological nature of the dual-frequency and dual-frequency wide lane carrier-wave differential equation is quite serious and irrelevant to the length of the baseline.To overcome the morbid nature,for single frequency data,according to Tikhonov regularization rule,the regularization matrix R is constructed and the regularization parameter a is determined,and A method of GNSS single-frequency single epoch baseline solution based on regrization is proposed,which is validated by the measured data.For dual-frequency data,the pseudo distance observation is introduced,Firstly,the fuzzy degree of wide lane is fixed gradually,and then the basic frequency ambiguity is fixed,and A method of GNSS dual-frequency single epoch baseline solution is proposed and the location effect under different cutofff height angles is analyzed by the measured data.2.Based on the first fixed ultra wide lane or wide lane ambiguity,and then fix the basic frequency ambiguity ideas,We choose to fix two ultra-wide lane ambiguities(0,-1,1)and(1,4,-5).first,and then combine two non-ionosphere combinations to achieve a fixed base-frequency ambiguity of the BDS.A method of GNSS single epoch baseline solution based on BDS triple-frequency constraint was established to realize the fast fix of ambiguity of GPS(Global Positioning System).The measured data shows that the Ratio average value of the BDS triple-fiequency constraint model is 1892,while the traditional model is only 392,which improves the reliability of the fixed ambiguity of CPS.3.Focusing on the complex constellation of the BDS in our country and large difference between various types of satellites,this article analyzes the relationship among the residuals,the signal-to-noise ratio and the height angle of carrier observations in different constellations satellites of zero baseline and ulhra-short baseline.According to the characteristics of the constellation of BDS,a stochastic model based on the distance between the satellite and the Earth,signal-to-noise ratio and height angle is proposed,and it is applied to the BDS triple-fiequency single epoch baseline solution.The result shows that compared with the traditional sinusoidal trigonometric function model,although the stochastic model combining the satellite-earth distance,signal-to-noise ratio and elevation angle has no obvious effect on improving the positioning accuracy.However,the success rate of baseline ambiguity resolution for 4.2 m,4.17 km and 8.84 km increased by 0.1%,4.7%and 1.1%and enhances the stability of the solution.4.Taking 1222(1)wodcface in the first mining area of Zhujidong Coal Mine as the research object,this paper studies the application of the single-epoch GNSS solution in monitoring the settlement of the mining area.The solution shows that the exterior checking precision of the planar point error is 13.6 mm,with an averagn of 10.6 mm by using the GNSS single epoch baseline solution proposed in this paper,it can basically meet the requirements of mining subsidence monitoing in plane.However,the elevation accuracy cannot meet the monitoring requirements. |
