Questions tagged [vegetation-index]

For questions about vegetation indices, which are measures of the relative abundance of vegetation. In the context of remote sensing and GIS, vegetation indices are usually encountered as a raster dataset.

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How to georeference multispectral raster without loss of data

I am trying to align two rasters made of data captured during same flight, but with separate cameras (drone - onboard, and Micasense RedEdge) and two separate gps devices (drone and another one ...
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972 views

ENVI band math incorrect values

I'm attempting to calculate vegetation indices in ENVI 5.2 using level-2 AVIRIS data in band math. The indices I'm working with are Vogelmann Red Edge 2, normalized difference red edge, and red edge ...
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GEMI vegetation index calculation in ENVI

I want to calculate gemi index, but I can't write its formula in ENVI, this doesn't work. gemi formula is: (n(1−0.25n)−RED−0.1251−RED) n = ( 2 * ( NIR ^2 - RED ^2) + 1.5 * NIR + 0.5 * RED ) / ( NIR ...
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Calculating Surface Roughness from Land Cover Data/Land Elevation

I'm trying to create a surface roughness file over the continental United States in NetCDF format. I've surface elevation file of 200 meters resolution and land cover data of 30meters resolution. I'm ...
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168 views

Using output of unsupervised cluster analysis to train supervised classification for vegetation mapping?

I'm using Google Earth Engine to classify mangrove forests from Landsat imagery to calculate extent. Let's say I perform an unsupervised K-means cluster analysis on a Landsat scene to identify general ...
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70 views

When to rescale reflectance data to calculate vegetation indices

I'm attempting to calculate a number of vegetation indices using hyperspectral AVIRIS data in ENVI. Some of these indices are normalized, such as NDVI, whereas others are not, such as the Transformed ...
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59 views

Using Band Math in R Creates Raster with Different Coordinate System?

I am trying to make a simple NDVI raster from a Landsat 8 image (containing bands 2-7). The Landsat image has a Coordinate System of NAD_1983_UTM_Zone_11N (and datum: D_North_American_1983). When I ...
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91 views

Method in QGIS to classify veg from HiRes geotiffs created in Pix4D?

I have 10 2D geoTIFF orthophotos (~2GB each, ~3km2 each, all 4.2cm/pixel) that I generated from Vis RGB 12MP images in Pix4D for a desert vegetation survey over 30km2 for a development. I need to ...
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QGIS: Extract rows of grape vines from inter-row vegetation using a 3D point cloud

I have some multi spectral imagery (raster data) from a UAV of vineyards in Victoria, as well as corresponding 3D point cloud (also raster) of the vineyard topography, based off ultrasonic sensing, ...
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194 views

Why are Landsat-8 derived NDVI values higher than SAVI values?

I have calculated NDVI and SAVI vegetation indices for a landsat-8 image. I am unexpectedly getting higher values for the NDVI than SAVI. What may be causing these unusual results? NDVI=0.46 SAVI=0....
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23 views

Understanding why MSAVI II values are outside the theoretical range

I am trying to understand why certain vegetation indices do not fall into the -1, 1 theoretical range. I generated Modified Soil Adjusted Vegetation Index II values in Google Earth Engine using ...
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1answer
38 views

Moisture Stress Index - how important is seasonal influence in a deciduous forest?

I want to calculate moisture stress index for a deciduous forest using the formula from the article 'Detecting vegetation leaf water content using reflectance in the optical domain' (Ceccato et al. ...
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Landsat surface reflectance product and low sun angles

I am trying to find out functional way to map arctic greening in Svalbard, Norway. Area of interest lies in the 78th parallel north. Most of the images during growing season have high cloud cover. I ...
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Issues calculating RedEdge indices from Sentinel 2 Data

I have calculated NDVIre3 from Sentinel 2A MS data in QGIS. As a pre-processing step, the Sentinel 2 bands (L1C product) were corrected using DOS1 algorithm available in QGIS 3.4.1 SCP plugin. The ...
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207 views

Calculating vegetation indexes with GDAL raster calculator?

I want to calculate a few of vegetation indexes [ example: NDPI (red band-green band)/(red band + green band)] in a model with the GDAL raster calculator but I don't know how put the equation here:
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Google Earth Engine: Use multiple bounding boxes to extract mean VI value

I am new to GEE with no prior Javascript knowledge. I am trying to find a way to use multiple bounding boxes (which are in bottom-left point x,y and top-right point x,y) from a csv file in order to ...