Paper Satellite Simulation Of Ground Stations And Improvement

The development of the Pico-Satellite is a significant trend in the aerospace area. Pico-Satellite has advantages of low weight, high performance, short R&D period and low expense. It will be used in Communication, Navigation and Deep Space Exploration and so on. The satellite clusters in the orbit form the constellation. Pico-Satellites share resources and information with each other, and do some virtual carry tests. Also they can realize the function of telecontrol and remote test.The Ground Station can realize the measurement and surveillance of Pico-Satellite. But it's a complex and huge system which has long R&D period and high expense. In order to test the Pico-Satellite in the lab, we must research a cheap Ground Station. Along with the development of TT&C, the Ground Station can not suffice the request of test for the Pico-Satellite. This thesis discusses the improvement of the Ground Station, which's performance is much stabile. It can suffice the request of the test for the Pico-Satellite. Main features of this thesis are as follows:The terminal processing circuit of ranging in the Ground Station is improved. The narrowband filters are added to the circuit, which make the side tone much stabile and the result of ranging much precise. Also it realizes the method of multiple side tone ranging.The phase counter is designed by using digital circuit, which can realize the intelligent processing of the data. This phase counter measures the phase-difference of side tones by using phase detector, which makes the measurement much precise. Then it sends the data to PC by USB. Because the crystal oscillator of 100MHz is used in the counter, the maximum error of measurement is only 0.36°.The statistic program of ranging is designed by using Matlab. The manual method of data processing can not realize the development of side tone ranging. But the statistic program can process the information of ranging quickly, which makes the results much creditable.The Phase Noise of the Ground Station is simulated by using Matlab. The performance of Ground Station affects the precision of ranging directly. The thesis analyzes the Phase Noise of Lo-Loop, Track-Loop, Nesting-Loop, Pickup-Loop and demodulator, and shows the effect of phase noise to the ranging system.> The performance of ranging is measured by using the way of null error and RMS jitter measurement. Then the results are analyzed by SPSS. According the results of analyzing, the Ground Station is improved by using mean. At last, the Pico-Satellite and the Ground Station is joining together. For the side tone of 100 KHz, the Null Error is 37.6519° and the RMS Jitter is 0.5634°. The precision of the side tone of 100 KHz determines the precision of the orbit of Pico-Satellite, the precision of measurement is reached 4.695m .The Ground Station has been improved successfully, who's function and performance are much better. The ranging system is intelligent and digital now and the result is much precise. Also the analysis of phase noise is directly improving the precision of ranging. Throughout the measurement and analysis of Null Error and RMS Jitter of ranging system, the Ground Station can adjust its self and the function of ranging is much prefect.