The LTDR project will produce, validate and distribute a global land surface climate data record (CDR) using a combination of mature and tested algorithm and the best available polar-orbiting satellite data from the past to the present and which can be extended into the NPOESS era. The project will create the daily surface reflectance product as the fundamental climate data record (FCDR), and will derive daily Normalized Differential Vegetation Index (NDVI) and LAI/FPAR as two thematic CDRs (TCDRs). The project will also attempt to produce higher level products such as burned area, albedo and BRDF at monthly temporal resolution.
The project will use the best available data, addressing the dynamic data continuity of the input observations, which will be primarily from the AVHRR and MODIS with differing spatial resolutions of 4km GAC (1981-present) , 1km HRPT and LAC (1992-1998), 250m to 1km MODIS (2000-present).
The GAC data from the AVHRR sensors onboard the NOAA satellites from 1981 - present is reprocessed by applying the preprocessing improvements identified in the AVHRR Pathfinder II project and the atmospheric corrections used in the MODIS preprocessing. The project will compare the AVHRR results with MODIS products where the two instruments overlap in time (from 2000 on for MODIS Terra and mid-2002 for MODIS Aqua). A gap in the data record from these two instruments will be filled using a SPOT VEGETATION surface reflectance product (1km) generated by the European GEOLAND2 project.
This Land Long Term Data Record will lay the foundation for continued climate monitoring with the VIIRS instruments onboard the NPP and NPOESS satellites.