Comparison of AVHRR-Based Global Data Records

摘要

Several global data sets have been developed from the AVHRR instrument measuring reflectance/emission of the Earth since the early 1980s. The longest datasets currently available for users are NOAA's Global Vegetation Health (GVH), NASA's Global Inventory Modeling and Mapping Studies (GIMMS) and Land Long Term data Records (LTDR). The GVH has 30-year records (1981-2010), GIMMS - 26 (1981-2006) and LTDR - 19 (1981-1999). These datasets have different spatial and temporal resolutions, processing methods (sampling, calibration, noise removal, mapping, gap treatment etc.), applicability, availability, distribution etc. They have been used frequently for monitoring earth surface, atmosphere near the ground and analysis of climate related land surface trends. Since one of the common features of these datasets is the Normalized Difference Vegetation Index (NDVI) this paper is focusing on comparison of NDVI time series, specifically comparing time series dynamics and trends. It is shown that GIMMS NDVI is two to three times higher and has steeper long-term trend compared to GVH and LTDR.