ISSN:
1572-9893
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geography
Notes:
Abstract A Method is proposed for detecting vegetation change using global area coverage data from the NOAA-7 Advanced Very High Resolution Radiometer. Other methods of vegetation change detection, such as baseline images, are discussed, but not demonstrated. Vegetation Change Detection Images are produced by combining three separate weekly composites of Channel 2 minus Channel 1 AVHRR data. This compositing method takes the highest value of the differenced data for each week period and each pixel location. Three such weekly composites red imaged by individual red, green and blue CRT color guns respectively and then combined to form a color composite. The Vegetation Change Detection Image has 20 km resolution. It can be used to show an entire continent on a single image when the data point to CRT pixel ratio is 1:1. The vector vegetation change (magnitude and direction) is depicted by the color pattern resulting from the relative amount of red, green and blue placed in the pixel due to the individual weekly color composites. If there is no greenness change at a pixel location the amount of red, green and blue will be the same and a gray scale color results. The VCDI could provide a timely “first alert” for identifying regional and global agricultural changes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00150766
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