Research On High Precision Measurement Technology Of Multi-satellite Formation Based On Double-sided Two-way Ranging

Micro-satellite formation is one of the most active new technology fields in the space field.The formation consists of several physically separated micro-satellites.The cooperation between satellites is realized through inter satellite communication and other technologies.Micro-satellite formation has the advantages of low cost,short development cycle,flexible configuration,long life cycle,long measurement baseline,etc.The performance of inter satellite relative measurement is the decisive factor affecting the capability of micro-satellite formation.The main measurement methods include GPS indirect measurement and RF autonomous measurement.Although GPS indirect measurement technology is mature,it cannot be used in medium,high orbit,deep space because of the limited coverage of GPS signal.RF autonomous measurement is to realize the internal autonomous measurement of the formation through the radio signal transceiver mounted on the satellite,and it can combine the application scenarios to design the appropriate measurement mechanism,which can overcome the problem of GPS indirect measurement.However,at present,the research on the inter satellite RF autonomous measurement method is mainly focused on the double-satellite formation,and there is still a lack of scalable and high-precision multi-satellite measurement scheme suitable for micro-satellite formation,which has become a bottleneck problem restricting the development of multi-satellite formation.In view of the above situation,this paper proposes a multi-satellite formation relative measurement scheme based on double-sided two-way ranging.Based on the principle of double-sided two-way ranging and satellite formation scene,the measurement performance is analyzed in theory,including the influence of frequency deviation of frequency source,ionosphere delay,hardware delay,high dynamic of satellite,observation noise and other factors on ranging accuracy.Then based on theoretical analysis,an inter satellite measurement system based on the measurement scheme is designed and implemented,and the corresponding experimental platform is built to verify the measurement system.The experimental results show that the relative measurement system of multi-satellite formation can operate normally and stably.Under the condition of 90 d BHz carrier noise ratio,frequency accuracy 0.5ppm,Allan variance 0.8ppb frequency source and time slot length 3 seconds,the mean error of ranging results is centimeter level and mean square error is decimeter level,which is consistent with the results of theoretical analysis.