Wavefront detection and reconstruction method for the active optical system of a large FOV space camera based on a self-reference light source

The application of active optical technology in a large field-of-view (FOV) pushbroom imaging space camera (PISC) can compensate for optical system aberrations caused by the space environment in real time. Additionally, it can improve the resolution while ensuring high imaging quality and enhance the value of remote-sensing data. The existing reference light sources (RLS) cannot meet engineering requirements; therefore, a method of setting a planar sampling mirror array in the plane area of a space camera's secondary mirror aperture is proposed for wavefront detection and reconstruction. Using the wavefront aberrations of a near-realistic distorted optical system as a benchmark, through numerical calculations and simulation analysis, the RMS value of the fitting residuals between the wavefront and the primary mirror shape in each FOV is less than λ/100. The experimental results are basically consistent with the simulation and theory, and the fitted surface residual RMS = 8.7 nm.