A simple method to account for off-nadir scattering in the NOAA/NASA Pathfinder AVHRR Land Data Set

The radiometric distortion of reflected radiation received by the NOAA AVHRR sensor is brought on by the effects of viewing and solar illumination geometry, as well as atmospheric effects. This may lead to a gross underestimation of bioproductivity or crop yield from models which use high temporal resolution NOAA AVHRR data as an input. Accordingly, a simple angular correction method is presented using daily NDVI data over the Sudan from July, 1989 derived from the NOAA/NASA Pathfinder AVHRR Land Data Set. Its simplicity and expediency may render it suitable for operational monitoring programmes such as famine early warning