Research On The Link Channel Model And Link Compensation Method Of The Satellite-ground Laser Ranging

With the rapid development of aerospace technology in our country.The precision of satellite laser ranging(SLR)technology will face a new challenge.However,the transmission and scattering effect of laser in atmosphere is an important factor that affect the precision measurement of SLR in the satellite-ground link,deep-space link or air-ground link.In this paper,a comprehensive research of laser transmission and scattering effect in channel environment are studied and channel model of satellite-ground link laser ranging is established in the background of the satellite-ground link laser ranging.Combining with the modified laser ranging method,qualitative and quantitative analysis of the transmission and scattering error factor are studied.Then the corresponding range error compensation scheme is proposed to maximize the accuracy of ranging system,which has an important theoretical significance and a practical value to further improve the precision of satellite laser ranging The main work of this paper is as follows.In this paper,the technology of laser ranging system is discussed and classified.Pulse ranging method and traditional phase ranging method are introduced in detail which are the typical of the non-coherent detection of laser ranging technology.The working principle of coherent detection laser ranging technology and its advantages compared with non-coherent laser ranging technology are introduced.The improved method is performed in the form of the pulse signal modulation mode combined with the phase signal modulation mode and with coherent detection and digital discrimination,which improve the existing pulse-phase laser ranging method Compared with the existing laser ranging method,this improved method is more suitable for the measurement of satellite-ground link.The transmission and scattering effects on laser in the atmospheric environment are researched,such as refraction,phase shift,flicker and depolarization.The mechanism of the different transmission and scattering effect is analyzed,and the channel model of satellite-ground laser ranging link is established.Then further established the clear sky atmosphere environment channel model and cloud,fog and rain environment channel model.The integrated channel characteristics under the specific environment are also discussed.Based on the propagation and scattering effects of the Troposphere Atmosphere on the laser,the error factors influencing the precision measurement of satellite laser ranging technology are analyzed.The results show that the important factor of laser ranging error is the phase scintillation caused by atmospheric,the refraction effect caused by atmospheric stratification,the atmospheric refractive index error and so on.The error factors are simulated and calculated,the ranging error caused by phase scintillation is micron magnitude,the ranging error caused by the atmospheric refraction is meter magnitude,the ranging error of atmospheric refractive index residuals caused by the empirical model of atmospheric refractive index is centimeter magnitude or even meter magnitude in this paper.The results show that atmospheric refraction effect and atmospheric refractive index residual are the main factors that affect the precision measurement of laser ranging.Based on the principle error factors of satellite-ground link laser ranging,the real and effective compensation for range error is analyzed,that is the atmospheric refractive index profile is accurate obtained in real time and obtain the minimum altitude when the atmospheric refractive index dropped to 1,which is also called the “troposphere height”.In this paper,a scheme of “real-time and site-specific” inversion of atmospheric refractivity index profile is presented,it can effectively compensate the ranging error caused by atmospheric refraction effect and atmospheric refraction index residuals.In this paper,the above main research work about the precision of satellite laser ranging have been done and some achievements have been obtained.These research results have important theoretical value and practical value for the accurate measurement of satellite laser ranging technology in the satellite-ground link.