Theoretical and numerical analysis of solar shape and intensity in state of solar occultation

A method for capturing the solar shape and intensity on occurrence of solar occultation is proposed, and a numerical simulation model is established. The solar shape and intensity matrix without atmospheric refraction effects is taken as a reference; the atmospheric bending angle at any position of solar image surface produced by atmospheric refraction is inversely calculated through the Abel integral formula and the vertical distribution data of refractive index. Then the displacement occurred by the occultation state is obtained. Based on the reference image surface, the shape and intensity matrix of the solar image surface after the occultation state can be obtained by geometric calculation. The numerical results indicate that the model can simulate the solar shape and intensity in different orbital positions and any tangent point. Solar shape and intensity at the tangent points from 5 km to 60 km are simulated when the height of the satellite orbit is 600 km, and the distribution map of solar intensity is obtained. This model is of higher reference value for realizing the solar simulator which can comparatively truly reflect solar shape and intensity in application in such fields like measuring and calibration of posture parts of satellite, remote sensing technology, material measurement and so on.