| In recent years,with the constant development of CNS/INS integrated navigation technology,the navigation technology based on star sensor is gradually developing from simple space application to broader airborne platform.The development of high-precision,all-day,and all-weather star sensor key technologies has important research significance and urgent application requirements.Focusing on the new trends in the development of star sensor technology,the research on the design of airborne platform star sensor system,star sensor star map simulation and star graph simulation model verification are carried out in this paper.The specific research work includes the following aspects:(1)The design of star sensor system.The working spectrum of the star sensor was determined based on the study of the working principle and design requirements.Based on the selection of the working spectrum of the star sensor and the type selection of detector,the design of optical system and the stray light suppression structure are completed,and the detection capability of the star sensor system is analyzed.The analysis results show that if the threshold of SNR is set to 5,the detection limit magnitude is 6.8 in the night environment.In the daytime environment,the detection limit magnitude is 5.5,which means that the difficulty in designing the star sensor system for the airborne platform is solved.(2)The star map simulation of star sensor.According to the mechanism of star sensor imaging simulation,a link for imaging simulation model of star sensor system is constructed considering all kinds of coupling relations.Based on the constructed simulation model,the imaging simulation process is designed,and the actual working process is simulated to acquire the simulated dynamic star map sequence.The design and realization of star map simulation software are completed including the structure design,function design and interface design of the software for star sensor.It provides the image data input for the subsequent imaging simulation model verification of star sensor,and solves the characterization problem of the link coupling relationship caused by the complexity of the imaging link.(3)The verification of star map simulation model.Based on the groundobservation data,data pre-processing is carried out to provide effective data for model verification.Based on the characteristics of the measured and simulated image data,starting with the quality evaluation of the image,the evaluation index system is constructed to characterize the credibility of the simulation models,including the size of the star spot,the SNR,the average gray level and the gray concentration degree.According to the established evaluation index system,the credibility of the simulation model is quantitatively evaluated through the error analysis of the evaluation indexes between the measured star map and the simulation star map.The analysis results show that the simulation model error is less than 15%,which solves the problem that the credibility of the star sensor imaging simulation model is difficult to be evaluated synthetically.In a word,through a series of researches on star sensor system design,star sensor star map simulation and implementation,star map simulation model validation and evaluation for airborne platform applications,the working process of the star sensor in the airborne platform is simulated,the reliability of the star sensor imaging simulation model is verified,and the theory basis and evaluation method are provided for the design and application of the space sensor platform star sensor system. |
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