Minimum Fuzzy Entropy Estimation Of Uncertainty Of BDS Data In Tangshan Coastal Area

In order to study the data quality assessment standard of Beidou navigation system,a study of data quality assessment and spatial data assessment methods for BDS data in Caofeidian region is carried out by combination with the characteristics of Tangshan coastal area.By comparing A and B assessment methods,analyzing the advantages and disadvantages and the scope of application,in the paper,it puts forward the information entropy theory to be as the research direction.Firstly,the origin,classification and entropy theory of uncertainty are made an analysis,and the distribution law of BDS data is analyzed.Through two 100 minutes or so;location data acquisition of static single point of coastal area control network,GNSS data is obtained.HGO software is used to resolve o files containing only BDS data,then it's to analyze the single point location result of each epoch by RTKLIB software,as a result,the discrete degree of single point positioning results of each epoch of BDS data,the fluctuation of each component data and the general law of BDS data distribution are obtained.Secondly,the fuzzy entropy model is established by the use of Gaussian-Markov model.It's combined with BDS data features through detailed membership function concepts and algorithms,using statistical method to establish the membership function in accordance with the characteristics of BDS data,finally,the minimum fuzzy entropy model of uncertainty is established.As Data analysis is realized by MATLAB software programming,the entropy on each epoch is obtained.By IGS the validity of data multipath,signal-to-noise ratio,internal and external accuracy of Wuhan station and Beijing station,the spatial BDS data quality of Tangshan coastal area is finally evaluated by entropy method and it's to determine the quality of data by scores.The higher the score is,the smaller the internal fluctuation of the data is,the better the quality will be.Based on the quality assessment of BDS data,the following three points are obtained:1.Spatial data not only shows random uncertainty but also fuzzy uncertainty.2.With comparative analysis,the minimum fuzzy entropy estimation is feasible.The difference of minimum fuzzy entropy is more obvious when the entropy value is close.3.BDS data on each epoch at Tangshan coastal area data fluctuates greatly,which is full of randomness,however,there has been fluctuating around a certain value.Figure 36;Table 19;Reference 53...