Study On Wild-Field-of-View And High-Accuracy Star Sensor Technologies

Star sensor is a high accuracy instrument for attitude determination. The new generation of autonomous star sensor is characteristic with wider FOV and higher accuracy as well as size, mass and power decreasing. The thesis explores the techniques aimed to wider FOV and higher accuracy under the background of the study on the new generation of star sensor.Analyzes the various infections on the detection ability by researching the star energy and system MTF. Estimates the magnitude sensitivity, magnitude valid range and probability of star capture based on signal detection and probability statistics. Derives and establishes the detection ability evaluation model, compiles the evaluation program and achieves the simulation result.For the hyper accuracy interpolation technique, which resolves the accuracy limitation of pixel physical size, derives out the star spot interpolation accuracy limitation based on the star spot mathematical model and photoelectric statistics. Two kinds of interpolation algorithms are analyzed and concluded that the centroiding algorithm is better for star spot position estimation. The noise effects on the centroding are analyzed by numeric simulation, educes the noise RMS model.With the research into the detection ability and estimation accuracy, achieves the conclusion that the wild FOV optical structure and the large area array CCD imaging system, which applied noise filter techniques, can effectively improve the star sensor performances.Illustrates several wide FOV optical structure forms, the features of diffractionoptics improving the performances of star sensor are demonstrated. A kind of hybrid optics of refraction and diffraction with a BOE is studied in a test star sensor.The performance parameters of CCD are expatiated. Based on the CCD noise model, analyzes the producing mechanism and features of the CCD noise. The noise elimination ability of CDS technique is analyzed and the improvement of SNR is calculated.A test star sensor, which based on the hybrid optics of refraction and diffraction with a BOE and the large area array CCD, is designed and developed. The static performances experiments and the star observation are carried out. The experimental results demonstrate the theoretic research work.