Comparisons of Compositing Period Length for Vegetation Index Data from Polar-orbiting and Geostationary Satellites for the Cloud-prone Region of West Africa

Land surface data from MODIS and AVHRR have been extensively used for vegetation monitoring. In cloud-prone areas like West Africa the use of Normalized Difference Vegetation Index (NDVI) data for vegetation monitoring is hampered by persistent cloud cover especially during the rainy season. The new geostationary satellite Meteosat Second Generation (SEVIRI MSG) is the first geostationary satellite suited for vegetation monitoring allowing NDVI to be derived with a 15-minute temporal resolution. For West Africa, MODIS (combined TERRA and AQUA) produce above 85 percent cloud-free pixels in the scene during the entire rainy season using 16-day composite periods. SEVIRI MSG data produces � 98 percent cloud-free pixels during the entire season using a 3-day composite period. Therefore, there is a much higher probability for producing high quality cloud free data using SEVIRI MSG data for a short time composite period compared to Polar Orbiting Environmental Satellite (POES) data, which is expected to substantially improve various applications of satellite based natural resource management, including vegetation monitoring, in West Africa.