Research Of The Compatibility And Interoperability Of Global Navigation Satellite Systems

Global Navigation Satellite System(GNSS)has been rapidly improved and used in military,society,economy and many other fields which plays an extremely important role in national defense and people's life.In this background,in order to defend their benefits,lots of countries and areas have been greatly invested in founding navigation satellite system with their own intellectual property.For instance,GPS of USA,GLONASS of Russia,COMPASS of China,GALILEO of EUROPE,QZSS of Japan and IRNSS of India are the primary navigation systems which are constructed or under construction.Because of the coexist and combination of different navigation systems,the assessment for compatibility and interoperability between these systems becomes a hot area in the satellite navigation field.The primary contents of this paper can be summarized as the next four components:Firstly,this paper introduced the background and development situation home and broad of GNSS,mainly studied the system component and navigation signal structure of GPS,GALELEO,CLONAS and COMPASS and especially analyzed the characteristics of the navigation signal of the new structure.Secondly,after analyzed.the original assessment model for compatibility,this paper proposed a new assessment model which considered the influence of data rate and the length of spreading code and also analyzed the influence of secondary code which is a commonly component in new signal structure.We perfected the original assessment mathematical formula and proved the accuracy of this formula with matlab in the end.Thirdly,based on the perfected formula,we quantificationally gave the condition under which the model for the signals with long code,high data rate and secondary code could be simplified so that the compatibility could be assessed quickly and accurately.In the end,we proved the correctness of this condition through simulation.Last but not least,aiming at the assessment of interoperability,an assessment model which combined the analytic hierarchy process(AHP)and entropy weight method was proposed.The new assessment model avoids the inaccuracy by subjectivity setting the weight for different assessment factors which analyzed the interoperability between different systems more accurate.In the end we gave a relatively better combination scheme under this new model.