Atmospheric scattering and turbulence modulation transfer function for CCD cameras on CBERS-02b and HJ-1A/1B

摘要

Atmospheric turbulence and aerosol scattering can produce the blurring of the remotely sensed image. The degrading effect is usually quantified by atmospheric modulation transfer function (MTF). However, this effect behaves differently with different remote sensors. The effort of this article is to study the different degrading effects of aerosol MTF and turbulence MTF between charge-coupled device (CCD) camera on China–Brazil Earth Resources Satellite-02b (CBERS-02b) and on Huan Jing-1A/1B satellite (HJ-1A/1B). Specifically, a corrected aerosol MTF model is established based on classical solution of small-angle approximation (SAA) model by considering the MTF and the effective instantaneous field of view (EIFOV) of CCD cameras. By assuming many different atmospheric conditions, the aerosol MTF and turbulence MTF for two CCD cameras are evaluated. It is found that the output aerosol MTF of CCD camera on HJ-1A/1B causes more degrading effect than that of CBERS-02b under the same atmospheric condition. However, the situation reverses for the turbulence MTF. Furthermore, CCD images acquired over Beijing, China, by CBERS-02b and HJ-1A/1B on four different dates are selected. The overall atmospheric MTF for these images are determined based on the aerosol products from Aerosol Robotic Network (Aeronet) and radiosounding data. Results indicate that the overall atmospheric MTF of CBERS-02b CCD camera reduces image quality more seriously than that of HJ-1A/1B CCD camera. Additionally, the atmospheric MTF compensation is performed and evaluated for these CCD images based on the overall atmospheric MTF.