Point response characteristics for the CERES / EOS - PM , FM 3 & FM 4 instruments

This paper describes the point source functions (PSF’s) of the Clouds and the Earth’s Radiant Energy System (CERES,) Earth Observing System (EOS,) afternoon platform (PM,) Flight Model 3 (FM3,) and Flight Model 4 (FM4) scanning instruments. The PSF (also known as the Point Response Function, or PRF) is vital to the accurate geo-location of the remotely sensed radiance measurements acquired by the instrument. This paper compares the characteristics of the FM3 and FM4 instruments with the earlier Proto Flight Model (PFM) on the Tropical Rainfall Measuring Mission (TRMM) platform, and the FM1 and FM2 Models on the EOS morning orbiting (AM) platform, which has recently been renamed “Terra.” All of the PSF’s were found to be quite comparable, and the previously noted “spreading” characteristic of the window (water vapor) channel PSF is analyzed