Community Research and Development Information Service - CORDIS

Tropical forest monitoring

Techniques have been developed for global tropical forest inventory using advanced very high resolution radiometer (AVHRR) and earth remote sensing satellite 1 (ERS-1) as the main sources of data. Special attention was given to the detection and monitoring of active deforestation. A comprehensive tropical forest information system has been developed to support the modelling of tropical deforestation dynamics. An intensive pan tropical data collection effort was made. Intensive observation of the equatorial belt by satellite has led in three years to the assembly of an almost adequate set of data. The problem of vegetation classifiction was addressed. Patchy AVHRR data was supplemented by intensive analysis. With single image classifiction and subsequent synthesis, most of the area of interest was covered. Maps at 1 to 3 000 000 scale were distributed to forest experts for evaluation feedback. Extensive field work has been carried out by regional specialists to support the thematic mapper (TM) analysis. Equal area estimates were found for the 20 to 30% forest cover situation; for lower cover percentage the AVHRR underestimates the true cover; for more dense cover, AVHRR overestimates the actual percentage. Other sampling approaches have been tested theoretically. A coherent geographical information system has been further developed. Regions, image windows and local data sets have been identified. Software and hardware were developed. Several preprocessing and processing steps such as calibration, spatial averaging, speckle filtering and classification have been developed in a prototype suite of tools. A geocoding/geolocation softwarepackage has been developed and is currently in a validation phase. A method of obtaining elevation data from synthetic aperture radar (SAR) interferometry has been described. The sensitivity of vegetation mapping from SAR data with respect to environmental parameters was studied and correction procedures for distortions developed.


Record Number: 12432 / Last updated on: 1995-06-19
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