Due to the large size of large-aperture aspheric mirrors and the long optical path each of them needs to inspect, the deviation of the optical axis from the structural reference cannot be accurately measured by conventional inspection means. However, as the aperture of the optical lens increases, alignment puts higher requirements on the concentricity of the optical axis of the mirror with the axis of the structure. Excessive eccentricity leads to severe consequences, including interference of the lens’ optomechanical structure, and non-adjustable misalignment. In this study, the accurate measurements of all the optical parameters of the mirror were realized by building an inspection optical path with mirror, measuring the spatial position of the apex of each optical component structure using a laser tracker, and testing the mirror through rotations. The conventional inspection methods and the inspection method of this study were simultaneously applied to the aspherical mirror with a diameter of 448 mm. Through the test results, it has been proven that the method proposed in this study is feasible.
The unification and recognition of meteorological parameter is the key to achieve long-time scale climate monitor, which is solved by space radiation benchmark with high precision. A space-borne whiskbroom solar reflection spectrum radiation benchmark is proposed in this paper, and the standard value transmission is more simple and reliable, achieved by the pendulum sweep institution with high stability. Based on the pendulum sweep institution, the spectral response of transfer and sun spectral radiometer and hyper-spectral earth imager is calibrated in-flight. And the primary benchmark is space-borne cryogenic absolute radiometer, whose absolute measurement uncertainty is 0.02%. Besides, the absolute measurement uncertainty of transfer and sun spectral radiometer and hyper-spectral earth imager is analyzed respectively in this paper, and the absolute measurement uncertainty is 0.23% and 0.63%.
Spectral image information provided by multi-spectral infrared remote sensing cameras has high application value. The registration of multi-spectral infrared camera is a key to improve the efficiency of satellite image acquisition. In order to break through the limitation of high precision of spectral segments imaging devices, a coordinate measuring and dual-path centering technology were proposed.
The polarization sensitivity is an important factor of quantification of remote sensing information, which is used to evaluate polarization response of remote sensors. In this paper, the white light laser, polarizing film, and the beam expander system make up the polarization measurement system. And then the polarization test is accomplished. Unlike the traditional analysis, this paper proposed a method of Fourier series fitting to analyze the polarization test data. Compared with the cosine function fit, Fourier series fitting is closer to the real data, and the influence of natural light and elliptic polarized light. And it has advantage in the error analysis of polarization test and can help improve polarization test precision. At last, the errors of polarization measurement is analyzed.