| The application advantages of high orbit satellite in early warning,communications,meteorology,space exploration and other fields are becoming more and more obvious,the requirement of application is becoming increasingly urgent,and the requirement of navigation precision and autonomy is increasing.This dissertation focuses on the requirements of autonomous navigation and navigation accuracy,and focuses on the autonomous navigation methods of high orbit satellite based on CNS/GNSS.The main contents and innovations of this dissertation are as follows:(1)Based on the ultraviolet sensor and GNSS measurement information,the autonomous navigation scheme of high orbit satellite is proposed.The orbit dynamics model and the observation model of the navigation system are established,and the actual availability of the single GNSS constellation and the joint constellation main lobe and the main/side lobe signal are analyzed by numerical simulation.The simulation results show that the availability of GPS system is the better than GLONASS and BEIDOU system when the main lobe signal of a single GNSS constellation is received.When the main and side signal received by high sensitivity receiver of GNSS constellation,joint GNSS constellation availability is the best,so the subsequent integrated navigation system simulation would use GNSS measurement information provided by joint constellation to achieve the required navigation performance better.(2)Based on the Fisher information matrix,a method for the observability analysis of high orbit satellite CNS/GNSS integrated navigation system is proposed.The system state CR lower bound is analyzed for the Fisher information matrix quantitatively of two kinds of measurement models which is the highest accuracy of the system states estimation can achieve.In the observation model of the equivalent installation error of the ultraviolet,the installation error angle of the X axis in the 3 rotation error angle is not considerable;in the observation model of the equivalent pixel error in the ultraviolet,the error of the 2 pixels is always considerable.The observability of the system is obtained by the PWCS method with the condition number of the observation matrix,which is consistent with the Fisher information matrix.The feasibility and correctness of the observability analysis method is further verified.On the basis of the analysis,the influence factors on the state observability of the autonomous navigation system of the high orbit satellite are analyzed.The optimal strategy is obtained by considering the ultraviolet sensor data update cycle,the available satellite set and the navigation constellation of high orbit satellite autonomous navigation.(3)On orbit calibration of high orbit satellite CNS/GNSS autonomous navigation system based on extended state method and least square method is completed.The simulation results of the 90 degree yaw maneuver of extended state method show that: for the error observation model of ultraviolet equivalent installation,considering the ultraviolet sensor and GNSS measurement information,the installation error of X and Y axis angle estimation is more accurate,but the estimation accuracy of Z axis misalignment angles relative to the pure ultraviolet sensor navigation improved by 50%,and the performance of the simple ultraviolet sensor is good if GNSS signals is lose.When two kinds of measurement information are considered,the X axis error estimation is more accurate,but the estimation accuracy of Y axis error is greatly improved.Based on the method of the least square method,the calibration method of high orbit satellite integrated navigation system is quite similar to the error estimation precision of the method.(4)A simulation platform of high orbit satellite integrated navigation is designed,which has good generality and expansibility.Three kinds of basic modules of navigation system are constructed,and the function of the digital simulation platform and the performance of the autonomous navigation algorithm are verified by the specific high orbit satellite autonomous navigation task. |
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