arvi
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This function is part of the larger class of vegetation-index methods used in satellite image-processing. See [[ndi]] or [http://www.beneaththewaves.net/Photography/Calculated_Greyscale_Images.html this discussion of related functions] for more detailed information. | This function is part of the larger class of vegetation-index methods used in satellite image-processing. See [[ndi]] or [http://www.beneaththewaves.net/Photography/Calculated_Greyscale_Images.html this discussion of related functions] for more detailed information. | ||
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ARVI is of the subtype which will return both positive and negative values. Positive values generally indicate the presence of vegetation (with greater values indicating healthier vegetation). Negative values generally indicate a lack of vegetation (water, rock, soil, etc.). | ARVI is of the subtype which will return both positive and negative values. Positive values generally indicate the presence of vegetation (with greater values indicating healthier vegetation). Negative values generally indicate a lack of vegetation (water, rock, soil, etc.). | ||
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The formula used is: | The formula used is: | ||
− | '''ARVI = (NIR - (2 * Red) + Blue) / (NIR + (2 * Red) + Blue)''' | + | '''ARVI = (NIR - (2 * Red) + Blue) / (NIR + (2 * Red) + Blue)''' |
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This formula was obtained from "[http://www.isprs.org/proceedings/XXXIV/part4/pdfpapers/059.pdf Above-Ground Biomass Estimation of Successional and Mature Forests Using TM Images in the Amazon Basin]" (Dengsheng Lu, Paul Mausel, Eduardo Brondizio, and Emilio Moran, 2002). | This formula was obtained from "[http://www.isprs.org/proceedings/XXXIV/part4/pdfpapers/059.pdf Above-Ground Biomass Estimation of Successional and Mature Forests Using TM Images in the Amazon Basin]" (Dengsheng Lu, Paul Mausel, Eduardo Brondizio, and Emilio Moran, 2002). | ||
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2000x1000x1 array of float, bsq format [8,000,000 bytes] | 2000x1000x1 array of float, bsq format [8,000,000 bytes] | ||
− | dv> result = arvi(nir, r, b) | + | dv> result = arvi(nir, r, b) |
Generating an Atmospherically-Resistant Vegetation Index image. | Generating an Atmospherically-Resistant Vegetation Index image. | ||
2000x1000x1 array of float, bsq format [8,000,000 bytes] | 2000x1000x1 array of float, bsq format [8,000,000 bytes] | ||
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-0.2554744482 | -0.2554744482 | ||
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− | [[Image:NYC-Band_Comparison.PNG|300px]] [[Image:Vegetation_Index-NYC-ARVI.PNG|300px]] | + | Full set of LandSat 7 imagery: |
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+ | [[Image:NYC-Band_Comparison.PNG|300px]] | ||
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+ | Output of arvi(): | ||
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+ | [[Image:Vegetation_Index-NYC-ARVI.PNG|300px]] | ||
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[[category:Landsat Science]] | [[category:Landsat Science]] | ||
[[category:User Defined Functions]] | [[category:User Defined Functions]] | ||
+ | [[category:Davinci's Shadow]] | ||
+ | [[category:Data Manipulation]] |
Latest revision as of 12:17, 2 May 2013
Contents: Description, Arguments, Usage, Examples, Images, Related Functions, Source Supported Under Version: > 1.00
Description Generates an Atmospherically-Resistant Vegetation Index map
Arguments and Return Values Arguments: 1- or 2-dimensional greyscale images representing near-infrared, red, and blue spectral bands (all three are required) Return Value: A float greyscale image
Usage Syntax: arvi(nir, red, blue) This function is part of the larger class of vegetation-index methods used in satellite image-processing. See ndi or this discussion of related functions for more detailed information. ARVI is of the subtype which will return both positive and negative values. Positive values generally indicate the presence of vegetation (with greater values indicating healthier vegetation). Negative values generally indicate a lack of vegetation (water, rock, soil, etc.). The formula used is: ARVI = (NIR - (2 * Red) + Blue) / (NIR + (2 * Red) + Blue) This formula was obtained from "Above-Ground Biomass Estimation of Successional and Mature Forests Using TM Images in the Amazon Basin" (Dengsheng Lu, Paul Mausel, Eduardo Brondizio, and Emilio Moran, 2002).
Examples dv> nir 2000x1000x1 array of float, bsq format [8,000,000 bytes] dv> r 2000x1000x1 array of float, bsq format [8,000,000 bytes] dv> b 2000x1000x1 array of float, bsq format [8,000,000 bytes] dv> result = arvi(nir, r, b) Generating an Atmospherically-Resistant Vegetation Index image. 2000x1000x1 array of float, bsq format [8,000,000 bytes] dv> max(result) 1.000000000 dv> min(result) -0.2554744482
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Recent Library Changes Created On: 07-16-2012 |