Analysis of space attitude measurement methods and optical design of refractive self-collimator in orbital environment

To monitor the space attitude of the spacecraft key load under on-orbit conditions and obtain three-dimensional angular deflection data, a folding-reflecting self-collimator was designed based on the Cassegrain optical system, and the evaluation indexes and imaging quality of the optical system were systematically analyzed, with the MTF of 100 lp/mm being better than 0.4, aberration being less than 0.0368%, and diffraction-limited dispersion spot diameter within 8.6 um, which meets the requirements for monitoring on-orbit. The principle of using multiple devices to combine to measure the three-dimensional angular deflection of the target load is analyzed, and the correspondence between the spot change and the target deflection angle is deduced. It shows that this method has a good development prospect in the field of space attitude measurement.