Simulation Analysis Of Capture And Tracking In Inter-satellite Link Of Tdrss

The tracking and data relay satellite system can effectively solve the problem that the medium and low-orbit satellite communication is geographically restricted and the satellite source information cannot directly reach the sink.Therefore,since the data and tracking relay satellite system is proposed,it has been the research of satellite communication.hot spot.The tracking and data relay satellite system establishes inter-satellite links with medium-and low-orbit satellites,or establishes multi-hop relay links between relay satellites.In the two processes,the establishment of inter-satellite links requires inter-satellite completion.Signal capture and tracking of two processes.The acquisition process of the inter-satellite link refers to the relay satellite scanning the uncertain area according to a certain scanning trajectory.When the beams of the target star and the relay satellite overlap each other,the capture process is successful;the inter-satellite link The tracking process refers to the process in which the relay satellites complete the acquisition of the target satellite and then finely adjust the beam through the beam to finally achieve accurate beam alignment and achieve long-term maintenance.In this paper,the signal characteristics analysis and simulation implementation of the inter-satellite link acquisition and tracking process are carried out.When studying the inter-satellite link acquisition process,the main influencing factors of the capture process are mainly modeled and simulated,and the target is The acquisition probability and acquisition time are calculated.The signal processing process of the angle tracking receiver is mainly analyzed during the tracking process of the inter-satellite link.Finally,the theoretical analysis and simulation are used to compare the demodulation results with different modulation methods.influences.Firstly,based on the research status and future development trends of relay satellites,the paper further studies the acquisition mode and establishment process of inter-satellite links;establishes and analyzes the models of capture processes in different coordinate systems,and uses the industry.The excellent STK software builds the foundation of the mathematical modeling of the acquisition process;the tracking process of the relay satellite system,the principle of the single-pulse angle tracking receiving antenna and the modulation method all have an important influence on the tracking speed and tracking accuracy.Some of the content was analyzed and simulated in detail.Secondly,this thesis conducts in-depth research on the capture process of inter-satellite links,including key parameter analysis and simulation of the capture process.In the process of capture,the determination of the capture uncertainty region is the most important research content.The uncertainty region is affected by multiple factors such as initial offset angle,orbit estimation error,and actuator execution error.By analyzing the initial offset angle,etc.The characteristics of the error,combined with the error distribution paper,derive the distribution of the initial offset angle and the expression of the captured uncertainty region,and verify the relevant results through simulation.Next,the paper studies the calculation model of the capture probability and captures it.Uncertain regions have the coverage of the target and the coverage of the scanning beam to capture the uncertain region.Different scanning methods have an important impact on the acquisition time and the operational complexity of the actuator.The optimal scanning step length is derived by using the isometric and other linear velocity scanning methods combined with the actual influencing factors such as platform jitter.Based on the above analysis,the comprehensive model of STK analysis of the relative motion between the satellites and the acquisition probability of the acquisition probability is derived.At the same time,the average acquisition time is calculated in combination with the scanning method.Finally,the paper analyzes and simulates the signal processing process of the single-pulse angle tracking machine used in the tracking process,which mainly analyzes and compares the performance of the angular tracking system under different modulation modes.By studying and comparing the demodulation principle and characteristics of two-phase modulation and four-phase modulation technology,the scheme adopted by baseband signal processing is determined.Next,the research on the processing of baseband signal focuses on the band in the process of baseband signal processing.The theoretical analysis and simulation are carried out by the sampling module,the carrier extraction module,the carrier tracking module,the envelope detection module and the coherent accumulation module.Then,the frequency uncertainty and signal-to-noise ratio of the receiver receiving signal are analyzed to determine the system.Simulation parameters;Finally,the two-phase modulation and four-phase modulation angle tracking system are simulated,and the accuracy and stability of the angular error demodulation results of the two modulation methods are compared by simulation.