Abstract

The effects of diffraction were calculated for selected current and future geosynchronous satellite infrared profiling and imaging channels. The future geosynchronous satellite calculations were made for the GOES I-M instruments. For comparison, some calculations were also made for similar measurements in low earth orbit. The results indicate that substantial diffraction effects, as high as 17 K, are and will be present for geosynchronous 15 μm profiling channels and 11 μm profiling and imaging channels when clouds are close to the sensor instantaneous field-of-view and the difference between the equivalent blackbody temperature between the cloud and the dear air scene is ≥ 20 K Similar diffraction calculations at 4 μm show a reduction of 5-10 K in the diffraction effects which suggests that, wherever possible, 4 μm channels should be used for profiling and imaging whenever quantitative radiometric measurements are made of surface properties (e.g. surface temperature).

© 1993 Optical Society of America