Multispectral image processing for environmental monitoring

New techniques are described for detecting environmental anomalies and changes using multispectral imagery. Environmental anomalies are areas that do not exhibit normal signatures due to man-made activities and include phenomena such as effluent discharges, smoke plumes, stressed vegetation, and deforestation. A new region-based processing technique is described for detecting these phenomena using Landsat TM imagery. Another algorithm that can detect the appearance or disappearance of environmental phenomena is also described and an example illustrating its use in detecting urban changes using SPOT imagery is presented.