Research On Attitude Determination Technology Of Near-ground Carrier Based On Atmospheric Polarization And SWIR Star Sensor Star Map

Because of its substantial autonomy,good reliability fast update rate and high pose accuracy,the star sensor is developing from the space application field to a broader range of near-ground space application fields.For the application of star sensors in near-ground space,affected by solid sky background stray light and complex atmospheric random disturbance,the system has problems such as insufficient star detection ability and difficulty in solving the three-axis attitude of the carrier.In order to improve the navigation accuracy,navigation reliability,and battlefield survival ability of weapons and equipment,this project takes complete account of the all-sky atmospheric polarization pattern and short-wave infrared(SWIR)stargazing ability from the application requirements of near-ground space star sensors.The SWIR star sensor imaging optical system parameter analysis method and the SWIR star sensor imaging link model construction method are studied.The attitude determination technology of near-ground carrier is proposed based on atmospheric polarization pattern and the SWIR star sensor star map.It provides technical support for the engineering practice of SWIR star sensor in armored vehicles,heavy tanks,and other weapons.Also,it provides theoretical methods for the scheme design,index demonstration,and evaluation application of the next-generation near-earth space and all-day star sensor in our country.The research works in the paper are summarized as follows:Based on the basic theory of atmospheric polarization,the characterization method of the all-sky SWIR atmospheric polarization pattern in the horizontal and tilt attitude is carried out.Based on the Rayleigh sky model and combined with the atmospheric depolarization effect,an optimization model for the all-sky degree of polarization in the horizontal attitude is given.Based on the constructed atmospheric polarization pattern in the horizontal attitude,combined with the attitude description method,the all-sky degree of polarization and the all-sky angle of polarization characterization model in the tilt attitude is deduced.The sky degree of polarization at the sun point is 0,and the sky angle of polarization contour lines converge at the zenith point and the sun point,which provides a theoretical basis for the research on carrier attitude calculation method combining atmospheric polarization pattern and the SWIR star map.Based on the star detection ability,the optical system parameter analysis method of the near-ground SWIR star sensor is proposed,including selecting optical system parameters and determining optical structure parameters.The H-band catadioptric star sensor optical imaging system is designed for the strong sky background in the atmosphere.The system’s image quality evaluation,tolerance analysis,temperature adaptability analysis,and stray light elimination optimization are completed simultaneously.The design results achieve the expected results,which prove the scientificity,rationality,and feasibility of the proposed SWIR star sensor optical system parameter analysis method.It provides a system model for the research on the construction method of the imaging link model of the near-ground SWIR star sensor.Based on the process of coordinate transformation,energy transfer,and image quality degradation,the imaging link model construction method of the near-ground SWIR star sensor is proposed,and the influence of atmospheric interference factors such as atmospheric background,atmospheric refraction,atmospheric turbulence,and aerosol scattering on the star sensor imaging is investigated deeply.Combined with the set star map simulation conditions and simulation process,the star map at an altitude of 0km is simulated.Combined with the quality evaluation index and engineering experience,the star detection ability of the designed near-ground SWIR star sensor optical imaging system is verified,which provides test input for the research on carrier attitude calculation method combining atmospheric polarization pattern and the SWIR star map.Based on the simulated atmospheric polarization pattern and the SWIR star map,the carrier attitude calculation method is proposed combining atmospheric polarization pattern and the SWIR star map.Based on the extracted coordinates of star points and sky polarization feature points,associated with the principle of singular value decomposition and matching,the combined feature matching recognition method is studied.Based on the results of combined feature recognition,combined with the principle of singular value decomposition and pose determination,the three-axis attitude joint solution method of the carrier is studied.It effectively deals with the problem of solving the three-axis attitude of near-ground carriers under intense sky background stray light and complex atmospheric disturbances.Further,it enhances the system’s navigation stability and robustness.