Chinese Space Science and Technology ›› 2018, Vol. 38 ›› Issue (3): 40-44.doi: 10.16708/j.cnki.1000-758X.2018.0033

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A method ofcalculatingintegraltimefor off-axis remote sensing camerabased on equivalent focal plane

WU Bin*, SUN Yanping, YIN Huan, ZHU Jun, LU Chunling, BAI Zhaoguang   

  1. Dong Fang Hong Satellite Corporation Limited, Beijing  100094, China
  • Received:2017-12-20 Revised:2018-01-25 Accepted:2018-03-06 Online:2018-06-25 Published:2018-03-06

Abstract:

At present, most of the in-orbit and in-producing optical remote sensing satellites are equipped with off-axis remote sensing cameras. In order to ensure the view axis imaging at the nadir, the camera needs to pitch a certain angle to compensate for the off-axis angle. As a result, there will be an angle between the focal plane and the horizontal plane of nadir when imaging by push broom and it will lead to an inaccurate integral time. An accurate method of calculating integral time based on equivalent focal plane was proposed. This method constructed an equivalent focal plane parallel to the horizontal plane of nadir. By establishing a strict geometric model, the pixel size corresponding to the real time of electric charge moving was calculated and thus the accurate integral time was obtained. Simulation experiments show that this method can increase the calculation accuracy of the integral time by 1.2%, and it will improve the image quality in orbit.

Key words:

integral time, remote sensing satellite, velocity-height ratio, off-axis optical system, image quality