Research And Implementation Of High Precision Satellite Ranging Technology

Measurement and control technology for aerospace is a very important technology in space technology,it is the guarantee of running normally for shuttle.A high precision satellite ranging technology is an important symbol for satellite navigation system performance successfully.For satellite ranging scheme,the pseudo code ranging is widely used,it has high ranging accuracy,strong anti-jamming,and can realize the code division multiple access,and many other advantages compared with other traditional ranging technology.This paper researched and realized the ranging transponder,in accordance with the need of a hign-precision ranging satellite.This paper using pseudo code ranging,and adopt the way of noncoherent forwarding.For pseudo code ranging,distance measurement precision mainly depends on pseudo-code phase measuring precision.And the measurement precision of pn code phase depends on the pseudo-code synchronization.So this paper research is focused on ranging system receiver's synchronization techniques,including pseudo code capture and tracking loop.The tracking loop is divided into pseudo code tracking loop and carrier tracking loop.For pn code capture,this paper adopt FFT algorithm based on pn code phase,because this capture algorithm computational complexity is small,capture time is short.In order to solve the problem that pn code sequence length does not match with the sequence length needed by the FFT algorithm,this paper improved the capture algorithm,and the simulation shows that the improved algorithm was not reduced the performance of the system in comparison with the method of direct zero padding method.Pn code tracking loop adopt the technology of carrier loop aiding pseudo-code loop,it has wide dynamic range,high tracking precision compared with direct tracking.In order to implement low power design,reduce the rate of hardware resources utilization,this paper adopts an improved pn code tracking loop structure,the simulation shows that pn code tracking loop can satisfy the requirement of the system precision.In order to realize the carrier loop can tracking the carrier phase accurately,and tolerate larger dynamic stress,this paper adopt second-order frequency lock loop auxiliary third-order phase-locked loop architecture.At the same time,this paper adopted a highly efficient phase discriminator and discriminator,reduced the rate of hardware resources utilization.The simulation shows that carrier loop can satisfy the requirement of system requirements.Finally,this paper realized the satellite ranging transponder by using FPGA,and done the ranging experiment.The statistical variance value was centimeter level,this paper realized the high precision range.