Data Biosphere GNV56

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The Amazonia Tropical Forest/Non-forest Map data set is one result of the work carried out at UNEP/GRID-Geneva by A. Cross from 1988 to 1990, under a cooperative agreement between GRID, the European Community (the Joint Research Center in Ispra, Italy) and Reading University, U.K. The first stage of this methodology development study was for large-area mapping, and the main product to result from it was this digital classification.

The Amazonia Tropical Forest/Non-forest Map data set is considered an experimental composite classification derived from several NOAA/AVHRR-LAC* digital images; five from 1988 and two from 1987 for a total of 7 scenes. The seven scenes were pre-processed to atmospherically and geometrically correct the data, followed by a precise georeferencing. A supervised maximum likelihood classifier was then used to categorize the data into one of five categories (see below). The last major step was to composite the seven scenes into a single digital map with the least cloud-cover as was possible, given the input classifications. The five categories are:

1) Forest; 2) Deforestation; 3) Cloud/Smoke; 4) Water; and 5) Savanna.

The Amazonia Tropical Forest/Non-forest data set is available on a source-approval basis to researchers only, as a single digital raster data file. Technical specifications for the data file are as follows:

Bits per pixel: eight Spatial resolution: 32.33 seconds lat./long.

Number of rows: 2624 (also lines, records of data) Number of columns: 4564 (also elements/pixels/samples)

Origin in DD/MM/SS: 07 52' 16" North latitude (northwest or -80 57' 11" West longitude upper-left corner)

Terminus in DD/MM/SS: -15 41' 31" South latitude (southeast or -39 58' 05" West longitude lower-right corner)

The reference to this data set is "Cross, A. M. 1990. Tropical Deforestation and Remote Sensing: the Use of NOAA/AVHRR Data over Amazonia, Final Report to the Commission of European Communities (D.G. VIII), Article B946/88, 60 pp."

* - the U.S. National Oceanic and Atmospheric Administration / Advanced Very High Resolution Radiometer - Local Area Coverage