8 votes

Tutorial Vegetation Condition Index

Kogan (2004) (p. 2891) provides the following formula for the Vegetation Condition Index (VCI): VCI = 100 * (NDVI - NDVImin) / (NDVImax - NDVImin) where, NDVI = Smoothed weekly NDVI value NDVImin ...
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  • 50.4k
8 votes
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Calculate MSAVI (Modified Soil-adjusted Vegetation Index) in Google Earth Engine

Both ways work just fine and give the same results: https://code.earthengine.google.com/3f766772035a8890b0caf231eb652a1f. There is also a small mistake in the formula in your code - wrong bracket. /...
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7 votes
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Why vegetation index, NDVI or SAVI is not working in the desert?

The sensitivity of the normalized difference vegetation index (NDVI) to the soil background and atmospheric effects has generated an increasing interest in the development of new indices. The NDVI ...
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  • 1,675
5 votes
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Atmospheric effects on extracting soil from BSI index?

Bare soil and urban areas are notoriously hard to segregate. Even with a perfect atmospheric correction, there will be relatively high confusion between the two, particularly when limited to ...
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  • 1,249
5 votes
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Seeking Function to calculate red-edgeNDVI in Google Earth Engine?

In your code, S2 is an ImageCollection, so when you "create band variables" you're just getting ImageCollections in which every image inside has only the selected band, which is useful. As you well ...
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5 votes
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Calculate and extract layer of NDVI change in Google Earth Engine

I used the water masking approach described here, which uses the Hansen forest dataset to mask out water. That is a global dataset so it may be suitable for your study area. Since you didn't provide a ...
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  • 2,016
4 votes
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Soil Adjusted Vegetation Index Values (MSAVI2) are Not Within Expected Range

This index has a slope correction so is not bound to a theoretical -1 to 1 range. Just for reference, here is the pseudo-code for the MSAVI2 that does not require the estimation of L. You may want to ...
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4 votes

EVI calculation from UAV multispectral survey

The common definitions for these coefficients when using MODIS are: L=1, C1 = 6, C2 = 7.5. The C1 and C2 coefficients are aerosol resistance terms that rely on the blue band to partial out atmospheric ...
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4 votes

Calculation of average NDVI of area in QGIS?

QGIS has a plugin called zonal statistics that will allow you to calculate the mean NDVI. It will also calculate the pixel count, and the sum of all pixel values within each polygon. If you wish to ...
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  • 805
3 votes

What is the index formula to calculate water stress index using multispectral sensor (Red, Blue, Green, Red edge, NIR)?

Depending on the camera you are using, and what bands, (Sounds like the micasense), you may want something that reaches towards the SWIR to see water characteristics. Anyways, from what I know- it ...
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  • 263
3 votes

How to represent seasonal variability in a single global NDVI map?

Potentials that I'd suggest that you look at are: NDVI percentiles - to indicate the highest & lowest NDVI values, without having the issues associated with anomalous min & max values. Range ...
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3 votes

Performing complicated calculation on bands in Google Earth Engine

I've never calculated this index, and am not convinced I got it completely right. But based on what you provided, it could look something like this: https://code.earthengine.google.com/...
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  • 9,780
3 votes

How to define areas from certain NDVI values in QGIS

These are two questions: First question: Explore the NDVI If you want to explore the values, without having to create a new raster, you can do it through the symbolism. Previously: The first thing, ...
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  • 1,354
3 votes

Computing Excess Green Vegetation Index (ExG) in QGIS

I would suggest OTB BandMath tool (from QGIS Processing Toolbox > OTB > Image Manipulation), which can handle bands calculation. Given ExG = 2 * G - R - B, the corresponding OTB Expression is 2*...
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  • 29.2k
3 votes

Computing Excess Green Vegetation Index (ExG) in QGIS

If you have some issue with OTB, it can also be used Raster Calculator as follows: After click in OK, result is totally equivalent.
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3 votes
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Google Earth Engine: calculate percentile rank in ee.ImageCollection

By definition, Percentile Rank (not to be confused with Percentile function or Percentile) is expressed as percentage so, if you want values from 0-1 you can only divide by 100. For calculating ...
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  • 26.9k
2 votes

How to analyze Vegetation Index using Sentinel-1 SAR Imagery?

According to me there are three (or four) possible way so far. 1)Leaf Area index from Statistics or water cloud model. 2) Radar Vegetation Index (RVI) from Dual-pol or quad-pol system and Radar ...
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2 votes

How to analyze Vegetation Index using Sentinel-1 SAR Imagery?

No way to calculate NDVI from SAR imagery, like Sentinel-1 images(any polarisations). To calculate NDVI you could get 2 bands (Near Infrared and Red bands) from Sentinel-2 or Landsat-8. So, about ...
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2 votes

What are the spectral indices that use addition of Landsat 8 bands for finding vegetation?

NDVI= (NIR-RED) / (NIR+RED) Found this which may help - http://www.harrisgeospatial.com/docs/broadbandgreenness.html Other resources which may be useful - https://blogs.esri.com/esri/arcgis/2013/...
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  • 57
2 votes

Creating NRG Multiband TIF from single bands using QGIS?

In QGIS: Raster menu -> Miscellaneous -> Build Virtual Raster (Catalog)... Ensure the "Separate" option is ticked so each raster is put into a separate band Raster menu -> Conversion -> Translate (...
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  • 53.4k
2 votes

Calculating forest canopy density and advanced vegetation index in ArcGIS Raster Calculator?

I think the equation in the raster calculator should be written as follows: (("TOA_B5.tif"+1) * (256-"TOA_B4.tif") * ("TOA_B5.tif"-"TOA_B4.tif"))**(1.0/3.0) **: means power convert (1/3) integer ...
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  • 36.5k
2 votes
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How to classify vegetation in 500x500 m polygons in a very coarse way in QGIS

Classification: (in case you don´t have a classified image already and/or if that´s new to you) Try the Semi-Automatic Classification Plugin, you find the user manual and some examples/tutorials here. ...
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  • 24.5k
2 votes
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Adding multiple indices as bands to image

map() function is for ImageCollection object. Computing median, you're converting ImageCollection object in Image object, thas why doesn't work your code. Try this: // Creating a buffer around my ...
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  • 12.2k
2 votes

How to create a dense pointcloud of trees in ArcGIS?

You dont mention how fast your model executes. I tried code below for three polygons, generating about 60000 random trees in one minute. Make sure not to input impossible combination of tree density ...
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  • 54k
2 votes
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Finding min and max raster values using polygons in ArcMap?

You can use Zonal Statistics as Table to accomplish this. The zonal data can be either raster or vector.
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  • 50.4k
2 votes

Calculating vegetation indexes with GDAL raster calculator?

You need to assign band designations based on the information provided by the sensor manufacturer. For example, if you are using landsat data, you can find them here: https://www.usgs.gov/faqs/what-...
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  • 2,536
2 votes
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Add several Spectral Indexes over an image collection in Google Earth Engine

You only need one semicolon at the end when you are applying map several times. Just remove the others: // Download the Sentinel-2 imagery collection var imgs = ee.ImageCollection('COPERNICUS/S2') ...
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  • 1,240
2 votes
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Extract pixel values from several bands of an image and export in a single table in Google Earth Engine

I'm assuming that you want one output row per input point, with columns for each of the properties you're computing. In that case, the best thing to do is to combine your multiple reduceRegions calls ...
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  • 9,046
2 votes

Vegetation indices extraction from RGB images

Having only RGB you cannot calculate the NDVI. As stated in the comment, you need as well the NIR (near-infrared) channel (https://gisgeography.com/ndvi-normalized-difference-vegetation-index/)
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  • 1,002

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