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.
71
questions
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1answer
20 views
Google Earth Engine - error in function to plot seasonal vegetation index for a region using MODIS data
I am trying to create a function to calculate the average Vegetation Condition Index
((mean NDVI of individual year)-(min NDVI from full period)) / ((max NDVI from full period) - (min NDVI from full ...
0
votes
0answers
6 views
Standardizing data over time (not space) in ArcGIS Pro 10.8?
I am trying to standardise Standard Precipitation Index data and Vegetation Health Index data over time on a 0 to 1 scale. I was previously using the fuzzy membership function to standardise the data ...
2
votes
1answer
30 views
Writing mathematical expression in Google Earth Engine
I am trying to run the expression below in Google Earth Engine to calculate Index-base Built-up Index(IBI)
var ibi = l8compositeMasked.expression(
'(2*SWIR/(SWIR+NIR)-((NIR/(NIR+RED))+(GREEN/(...
4
votes
2answers
179 views
Computing Excess Green Vegetation Index (ExG) in QGIS [duplicate]
I have to process the image for Sugarcane row detection and extraction.
Sample image is accessible from the link: https://github.com/AndresHerrera/croprows_generator_pa_v2/tree/master/droneimages
I ...
0
votes
1answer
47 views
Vegetation indices extraction from RGB images
I have been working on the project to classify crops as health or unhealthy. For this task I have taken the open source dataset from the the website https://www.sensefly.com/education/datasets . It ...
0
votes
2answers
123 views
How to define areas from certain NDVI values in QGIS [closed]
I downloaded LANDSAT images from 1985-2018 with Google Engine, 2 for each year. Now I want to know how has the vegetation varied over the years with NDVI, using QGIS 3.6.3. Having calculated the index ...
1
vote
0answers
56 views
Using LiDAR to identify coniferous and deciduous trees
Is it possible to use only LiDAR data to distinguish between mostly coniferous and deciduous forest? I have a LiDAR data from spring and summer, but they have different point spacing.
1
vote
1answer
53 views
Performing complicated calculation on bands in Google Earth Engine
I'm trying to perform ANIR index calculation on my image collection. I'm having trouble writing the code in the right way. ANIR index formula is :
cos^-1[((a^2)+(b^2)+(c^2))/(2*a*b)]
(a2, b2 and c1, ...
1
vote
0answers
33 views
Google Earth Engine unequal histogram values
I am creating histograms in Earth Engine of pixel values of cloud masked EVI from different years using Landsat 8. For each of the layers I create, I use an identical geometry to clip the output, but ...
0
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0answers
68 views
Google Earth Engine vegetation index
I am trying to make maps and histograms for Landsat EVI. My code (extract below and full thing attached) works but the results seem very strange. The histogram outputs are bimodal, despite the exact ...
0
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0answers
84 views
Habitat Fragmentation Index calculation
What is the correct plugin/function to calculate a Habitat Fragmentation Index in QGIS (I use the 2.18 version) or FRAGSTAT starting from a vector layer?
I suppose that, first, I must convert the ...
3
votes
2answers
143 views
Batch processing Vegetation Index with QGIS Raster Calculator
I'm applying the Green Leaf Index (GLI) to a multi-temporal set of RGB raster images to generate false colour overlays of the sections of the hay field. I can create GLI layers using the raster ...
0
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0answers
10 views
Where can I find reflectance / VI data for crops for different dates across their growing season?
I have been trying to find literature values for reflectance of soybean for different dates along the growing season (I am specifically interested in 30, 60 and ~120 days after planting - so the V3/V4 ...
0
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0answers
25 views
Possible range for MSAVI and MTVI indices
What are possible value ranges for MSAVI2 and MTVI indices?
The article #1 says it should be in range of -1 to 1, but the answer to the question #2 says '[MSAVI2] is not bound to a theoretical -1 to 1 ...
0
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0answers
28 views
Do Sentinel-2 L1C data downloaded from USGS Earth Explorer consist of reflectance values or digital numbers?
I was wondering if Sentinel-2 L1C data downloaded from USGS Earth Explorer consist of reflectance values.
And is it necessary to use reflectance values for time series analysis of Sentinel-2 ...
0
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0answers
12 views
Issues calculating VARI from Sentinel L2A
I have a dataset of Sentinel-2 L2A imagery for which I am calculating the Visual Atmospheric Resistant Index (VARI).
The bands that I am using (B2 = blue B3 = green B4 = Red)
I am working in ArcMap. ...
0
votes
1answer
160 views
Extract pixel values from several bands of an image and export in a single table in Google Earth Engine
I am creating several bands of spectral indexes by reducing the S2 TOA image collection.
For each spectral index, I am extracting the pixel values at specific locations (a point shapefile represent ...
1
vote
1answer
35 views
Add several Spectral Indexes over an image collection in Google Earth Engine
I want to add several spectral indexes in one go over a Sentinel2 TOA collection.
If I do only with NDVI the script works. If I add 2 types of NDWI I get the following
"Syntax Error: Unespected ...
0
votes
0answers
20 views
Vegetation detection of anthropic crops with Google Earth Engine
I am very new using Google Engine and I need to know how to detect only agricultural crops on slopes without them mixing with that natural vegetation on hills. I have tried different indexes (like ...
0
votes
0answers
65 views
How to average the NDDI index for a map in GEE
In previous codes I was able to generate the NDVI average, but since NDDI is a sub-index I would like to know if anyone would be able to generate this NDDI average in GEE
https://code.earthengine....
0
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0answers
17 views
clred- edge index for canopy chlorophyll content
I want to use clred-edge chlorophyll index to extract canopy chlorophyll content (CCC) from Sentinel-2
But based on the various articles I've read, I have two questions
Is there a numerical range ...
0
votes
1answer
37 views
Function only mapped over the first image of the collection
If anyone could help with this please.
I need to map a function over an image collection. The problem is that the function is applied only on the first image of the collection and not on the rest. ...
0
votes
0answers
54 views
ArcGIS - Band Arithmetic - VARI
I have a RGB raster image for which I need to calculate vegetation indices. I have chosen to use VARI from the "Band Arithmetic" options in the "Add Function" tool in the "Image Analysis" window.
...
1
vote
1answer
61 views
Loops for calculating vegetation indices for multiple temporal images and each image have multiple bands
I have 64 TIFF files of different dates, each date has 4 bands (123 and 4 for B, G R and NIR). I am trying to develop a Vegetation index for each date image. This is how the images in my folder are
[...
1
vote
1answer
144 views
Calculating EVI in ArcMap for Landsat 8 Image gives values ranging from 55155 to -23235 [closed]
How do I calculate EVI in ArcMap for Landsat 8 Image?
My values are ranging from 55155 to -23235.
I have tried using the formula:
2.5 * [(band 5- band 4)/ (band 5 + 6*band 4-7.5* band 2) + 1]
I ...
1
vote
1answer
81 views
MCARI vegetation index in ArcGIS raster calculator
I'm trying to write the equation for the MCARI vegetation index in raster calculator using WorldView-2 imagery, but can't get it right. Here is the original formula:
MCARI = [(RedEdge ā Red) ā 0.2 Ć ...
1
vote
1answer
396 views
Which band to use for LSWI?
I have a sentinel 2 L1C data and I am trying to calculate the Land Surface Water Index (LSWI) using the NIR and SWIR bands. As the Sentinel 2 data is having 2 SWIR bands (B11 and B12), I am confused ...
1
vote
0answers
60 views
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(1ā0.25n)āREDā0.1251āRED)
n = ( 2 * ( NIR ^2 - RED ^2) + 1.5 * NIR + 0.5 * RED ) / ( NIR ...
-2
votes
1answer
394 views
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 ...
2
votes
1answer
263 views
How do I add multiple indices as bands to an image?
I want to be able to classify my image using bands for prediction (B2, B3, B4, etc.) but I also want to use indices as "bands" (B2, B3, B4, NDVI, EBBI, MSAVI2, etc.). Unfortunately, I can't seem to ...
0
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0answers
125 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 ...
1
vote
1answer
184 views
Seeking Function to calculate red-edgeNDVI in Google Earth Engine?
I am trying to calculate the red-edgeNDVI ((NIR ā red edge)/(NIR + red edge)) of an Image.Collection in Google Earth Engine. There is a built in function for NDVI but not for red-edge NDVI. The code I ...
0
votes
1answer
126 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. ...
3
votes
1answer
861 views
Soil Adjusted Vegetation Index Values (MSAVI2) are Not Within Expected Range
I am using MSAVI2 (Modified Soil Adjusted Vegetation Index 2) to analyze different land cover classes for a study area in southern Africa. The Land cover classes were taken from a Planet Labs ...
1
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0answers
504 views
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 ...
1
vote
0answers
247 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 ...
0
votes
1answer
117 views
Is the resolution of MYD13A2/MOD13A2 ( MODIS 16 day 1km Global Vegetation Indices) erroneous in Google Earth Engine?
The MODIS vegetation indices collection shows a resolution of 111319.4 metres in Google Earth Engine when, in fact, it should be 1000 metres.
Below is my code:
var Veg = ee.ImageCollection("MODIS/...
4
votes
1answer
416 views
Why vegetation index, NDVI or SAVI is not working in the desert?
Could anyone explain why the vegetation indices are not working in the desert region?
I used Landsat 8 image which has been already radiometric/atmospheric corrected.
I want to see the fractional ...
0
votes
2answers
384 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:
2
votes
1answer
78 views
How to create a dense pointcloud of trees in ArcGIS?
I'm having a large dataset of forest polygons and would like to scatter individual tree locations over these areas. Here is how I have done this so far:
In "Create Random Points" number of points has ...
2
votes
0answers
122 views
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 ...
1
vote
0answers
114 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 ...
1
vote
0answers
124 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 ...
6
votes
1answer
433 views
EVI calculation from UAV multispectral survey
I want to calculate EVI index from UAV multispectral survey. For satellite imagery it is pretty straightforward (after reading multiple posts on GIS.SE) but not sure how to approach this problem, when ...
1
vote
1answer
2k views
Convertion of spectral indices formulas from Landsat to Sentinel
There are many spectral indices in literature. However, the formulas mostly refer to landsat imagery, and thus the corresponding spectral bands.
Question:
How can a formula that was originally ...
2
votes
2answers
2k 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 ...
3
votes
1answer
3k views
Calculate MSAVI (Modified Soil-adjusted Vegetation Index) in Google Earth Engine
How do you write the MSAVI formula in JavaScript function for Google Earth Engine?
I am trying to calculate the MSAVI as a function. The aim is to map the result over a Sentinel-2 composite and not a ...
3
votes
2answers
142 views
Vegetation Index for dry and sparse vegetated areas?
I found many different index for the estimation of vegetation cover, but many of them struggle in sparse areas with low vegetation cover, as the soil signals are way stronger than the vegetation ...
2
votes
0answers
211 views
EVI2 values dont' come out -1 to 1? [closed]
I'm very new to remote sensing in general, and aren't sure if I've made an error.
I've calculated EVI2 for a Landsat 8 and Sentinel 2 image. Both Top of Atmosphere. I've used Google Earth Engine to ...
0
votes
1answer
711 views
Calculating forest canopy density and advanced vegetation index in ArcGIS Raster Calculator?
While performing raster calculator operation in ArcGIS for Advanced Vegetation Index ( in calculating forest canopy density), the results show only 2 values i.e high (1) and low ( 0), instead of a ...
