Design And Implementation Of A Satellite-based Quantum Ranging System Simulation Platform

The measurement accuracy of traditional ranging technologies is constrained by the standard quantum limit.While the quantum ranging technology which uses the quantum optical properties including entangled and squeezed state of the quantum light,can break the accuracy limitation of traditional methods and further improve the accuracy to the Heisenberg limit.The quantum ranging scheme which uses coincidence measurement can provide a sub-picosecond level time difference of arrival(TDOA)measurement accuracy of the entangled light,which corresponds to a micrometer level ranging accuracy.It is foreseeable that if the quantum ranging can be introduced in the fields which rely on the ranging technology like positioning,navigation and guidance,the accuracy of the related processes can be effectively improved.Therefore,the research of quantum ranging technology is significant and has high value.Current quantum ranging systems are generally used in static measuring scenes,while in the satellite-ground ranging related application,it needs to measure the distance between the satellite and the ground user in the case of high-speed relative motion,and the difficulty of this process increases greatly.Thus,this thesis studies the satellite-ground quantum ranging process,it mainly focuses on three parts of the process:first is the modeling of the satellite orbits and the user-to-satellite observation curves;second is the design and working process simulation of the acquisition,tracking and pointing(ATP)system,and the last is quantum ranging based on quantum light transmission and reception.The main research contents and results are as follows:1.The process of modeling the artificial satellite orbit under two-body problem is analyzed by taking the quantum science experimental satellite "Mozi" as a research object.Based on six parameters of the orbit,the sub-satellite point trajectories are calculated,and the observability of the given ground user to the satellite is analyzed.Finally,the azimuth and pitch angle trajectories of the ground user's ATP system while tracking satellites are simulated and calculated.2.A two-dimensional gimbal and fast steering mirror(FSM)driven coarse and fine tracking nested ATP system simulation platform is designed.For the coarse and fine tracking system,a three-loop cascade proportional,derivative and integral(PID)controller and a model reference adaptive controller(MRAC)with adaptive strong tracking Kalman filter(ASTKF)are introduced to control them respectively.A simulation model of the ATP system based on the Simulink system simulation software is implemented,and the tracking process of the satellite is simulated.3.After tracking the satellite and establishing a bi-direction optical communication link,the transmission and reception process of frequency entangled photon pairs is simulated,and the second-order correlation function of the signal light and idle light in the photon pairs are fitted using coincidence measurement algorithm.Time difference of arrival(TDOA)of the entangled photon pairs is obtained by finding the extreme point of the function.The TDOA measurement error can reach 1 picosecond,which corresponds to a micrometer-level ranging accuracy.4.On the basis of realizing the satellite-based quantum ranging system,this thesis designs and implements a fully functional satellite-ground quantum ranging simulation platform with a user-friendly interface.The platform has functions such as system simulation,parameters input and output and results visualization,which can let researchers to conduct further research on satellite-ground quantum ranging and quantum positioning system.