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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Vegetative index returning impossibly high values

I am attempting to calculate a vegetative index from a mask layer for vegetation in a GeoTIFF image. The vegetative index is calculated simply as (r - b)/r on all pixels such that r !=0 and that ...
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26 views

MSAVI2 strange histogram on QGIS

I have written python code, where I extract bands from a UAV .tif image and I calculate MSAVI2 with this equation: msavi2 = (2 * nir + 1 - sqrt( (2 * nir + 1)^2 - 8 * (nir - red) )) / 2 (source: Soil ...
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2 votes
1 answer
106 views

Mapping salinity indices to pixel values

I have studied papers related to Soil Salinity indices that include equations such as this paper here. What I try for many days to find out, is how the increase or decrease in a Salinity Index is ...
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53 views

Vegetation classification for aerial photography in QGIS

What I need to do is to use QGIS, for vegetation classification of some older and newer Aerial Photography. In the past we have used ERADS Imagine but I have seen that there is some plugin developed ...
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1 answer
68 views

Google Earth Engine calculation of new Index NDRS

I want to calclulate this index in GEE. I managed to calculate the DRS, but I do not understand how to calculate the NDRS. Can you help? https://code.earthengine.google.com/?scriptPath=users%...
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  • 143
3 votes
1 answer
154 views

Calculate and extract layer of NDVI change in Google Earth Engine

My experience and expertise in Google Earth Engine are super low. My study area is Sundarban, Bangladesh. I have 2 NDVI from 2 years (2016 & 2017). I want to find the vegetation change by ...
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1 vote
0 answers
77 views

Calculating change area using NDVI in Google Earth Engine JavaScript API

I am new to Google Earth Engine and JavaScript. I am trying to visualize and calculate the changed area from the NDVI of 2 years (Landsat 8 surface reflectance). Can anyone help me to extract the area ...
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0 answers
26 views

Applying indexes to level 2A Sentinel products

I am using SNAP's Band Maths tool to calculate the following indexes: FDI (Floating Debris Index) PI (Plastic Index) NDVI (Normalized Difference Vegetation Index) FAI (Floating Algae Index) FAI uses ...
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35 views

EBBI Values too small

I'm trying to calculate EBBI at Google Earth Engine for images from Landsat 5, but the values that I get are too small. I've already tried change the study area and also making an image. But tha ...
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38 views

What is the range of Modified Triangular Vegetation Index 2 (MTVI2) and what high value of MTVI2 means

I'm at loss in understanding the range of Modified Triangular Vegetation Index 2 (MTVI2). The formula for MTVI2 as described in this paper is, I used different combinations of NIR, red, and green ...
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  • 193
1 vote
2 answers
367 views

Extracting NDVI value for GPS points - how can I extract NDVI value for specific date and time for each GPS point?

I am quite new to GEE and trying to extract the NDVI value for a set of GPS points (X, Y, and date). I have constructed my NDVI layer and am able to obtain NDVI values for my points, however the date ...
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152 views

Modified Chlorophyll Absorption Ratio Index (MCARI) vs Green Chlorophyll Index (GCI) in a desert

I am using UAV multispectral data to compute different vegetation indices. Both of these indices were computed with the purpose of seeing/assessing the chlorophyll content, thus indicating if the ...
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1 vote
0 answers
98 views

MSAVI vs NDVI for deserts

I calculated NDVI (Normalised Difference Vegetation Index) and MSAVI (Modified Soil Adjusted Vegetation Index) for a desert environment, where most of the vegetation is shrubs with some trees using ...
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0 votes
1 answer
139 views

Getting error computing VCI in Google Earth Engine

I have tried to use this code: https://code.earthengine.google.com/?scriptPath=users%2Fjohanneswilk%2Ftest%3ATest_13%20MODIS%20VCI%202 but there is the following error message: Line 170: MonthlyMAX....
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1 vote
1 answer
224 views

GEE- Calculating Burned Area Index for Sentinel 2 (Filipponi et al. 2018) but getting binary result than index range

I am trying to calculate BAIS2 index for sentinel-2 collection over a study area in Google Earth Engine. I tried to create a function using expression but end result is binary image rather than index ...
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0 answers
45 views

Indices similar to EVI for vegetation health analysis using UAV multispectral data

I know NDVI is the most commonly used index to start with vegetation health analysis. I am looking for other indices that can be calculated when the available UAV imagery has NIR, Red, Red Edge, Blue ...
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1 answer
35 views

Expression for Modified Triangle Vegetation Index 2, Landsat 8

I am trying to run the index. In order to get it, I'm using raster calculator. Wrote the expression, but it's not coming rightly. Could one check and revert whether the expression is right? ((1.8 * (&...
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1 vote
0 answers
104 views

Python - Calculating Burned Area Index results in empty plot

I've followed this tutorial to calculate the dNBR Index, using the given sample tif files which contain a burned area. My results were as shown on the tutorial. So far so good. Then I tried to ...
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0 votes
1 answer
36 views

Turning NDWI values into percentage from -1 to 1

The usual values of NDWI, NDVI e.t.c come as -1 to 1. I want to show these values as 0-100%. How shall I do that with the raster calculator?
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3 votes
2 answers
233 views

Google Earth Engine: calculate percentile rank in ee.ImageCollection

I am trying to calculate the Vegetation Productivity Index sensu copernicus in Google Earth Engine, which requires estimating the percentile rank. I haven't found any lead so far on how to do so, does ...
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  • 117
-1 votes
1 answer
100 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 ...
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1 answer
32 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 ...
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2 votes
2 answers
251 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/(...
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5 votes
2 answers
2k 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 ...
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  • 529
0 votes
1 answer
255 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 ...
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0 votes
2 answers
598 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 ...
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1 vote
0 answers
112 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.
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1 vote
1 answer
334 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, ...
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1 vote
0 answers
107 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 ...
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0 votes
0 answers
330 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 ...
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3 votes
2 answers
313 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 ...
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0 votes
1 answer
480 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 ...
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  • 531
1 vote
1 answer
134 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 ...
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  • 531
0 votes
1 answer
65 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. ...
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  • 25
1 vote
1 answer
120 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 [...
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  • 13
1 vote
1 answer
285 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 ...
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  • 11
1 vote
1 answer
141 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 – Red) – 0.2 × ...
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  • 11
1 vote
1 answer
980 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 ...
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1 vote
0 answers
108 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(1−0.25n)−RED−0.1251−RED) n = ( 2 * ( NIR ^2 - RED ^2) + 1.5 * NIR + 0.5 * RED ) / ( NIR ...
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-2 votes
1 answer
710 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 ...
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2 votes
1 answer
623 views

Adding multiple indices as bands to 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 ...
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0 votes
0 answers
296 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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  • 53
1 vote
1 answer
291 views

Seeking Function to calculate red-edgeNDVI in Google Earth Engine?

I am trying to calculate the red-edgeNDVI ((NIR – 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 ...
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  • 331
0 votes
1 answer
233 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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4 votes
1 answer
1k 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 ...
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  • 115
1 vote
0 answers
590 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 ...
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1 vote
0 answers
275 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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0 votes
1 answer
164 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/...
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5 votes
1 answer
641 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 ...
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  • 55
0 votes
2 answers
433 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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