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VEGETATION - 2000

Lake Maggiore - Italy, 3-6 April 2000


An evaluation of SPOT-VEGETATION, for land cover mapping and the evaluation of forest resources, I: Mato Grosso, Brasil.

Jones, S. D. Eva, H. D.,
SAI, JRC Italy

The need for timely, low-cost, high quality land cover information from earth observation is of particular importance in the humid and sub-humid tropics. This paper focuses on the state of Mato Grosso, Brasil, which lies at the heart of the arc of deforestation in the Southern Amazon. In this context SPOT VGT S-10 and S-1 products are evaluated along side the commonly used NOAA-AVHRR LAC product and the ERS-2 ATSR GBT.

The evaluation focuses first on sensor-platform attributes including possible bi-directional capabilities and effects, geo-locational accuracy, near-real time monitoring, cost, radiometric and spectral characteristics.

Secondly, several land cover assessment methodologies are attempted: (i) unsupervised classifications (ISOCLUSTER) were performed and expert interpretation solicited; (ii) several vegetation indices were then performed and results compared; and (iii) analysis of the spectral phenology, derived from temporal composites, was undertaken. These results were then validated by Landsat TM coverages and collaboration with Brasilian agencies.

Preliminary results suggest that VGT (and LAC) data are more suitable for rapid continental-scale evaluations and seasonality studies. VEGETATION data consistently producing high quality image products but being let down by its geolocational accuracy and internal sampling routines. More detailed studies, at a regional-scale (the case in Mato Grosso), benefited greatly from the increased spectral (smaller band-pass widths) and geometric accuracies of the ATSR-2 sensor.

Possible synergies between these three data sources are then explored.