9
votes
Accepted
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.
/...
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 ...
- 51.5k
7
votes
Accepted
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 ...
- 1,725
5
votes
Accepted
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 ...
- 1,287
5
votes
Accepted
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 ...
- 9,985
5
votes
Accepted
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 ...
- 1,896
4
votes
Accepted
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 ...
- 31.4k
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 ...
- 31.4k
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 ...
- 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 ...
- 6,486
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/...
- 13.8k
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, ...
- 1,284
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*...
- 30.5k
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.
- 29.7k
3
votes
Accepted
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 ...
- 29.7k
3
votes
Accepted
Compute kNDVI using R
It seems you are using Digital Numbers instead of reflectances as specified by the paper. Just divide band values by 10000 before calculating knr.
# get reflectance values
s2_red<-s2_red/10000
...
- 1,561
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 ...
- 293
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 ...
- 455
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/...
- 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 (...
- 64.9k
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 ...
- 40.5k
2
votes
Accepted
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. ...
- 29.3k
2
votes
Accepted
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 ...
- 13.2k
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 ...
- 68.9k
2
votes
Accepted
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.
- 51.5k
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-...
- 2,862
2
votes
Accepted
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')
...
- 1,561
2
votes
Accepted
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 ...
- 10.2k
2
votes
Batch processing Vegetation Index with QGIS Raster Calculator
You can try using the "Graphical Modeler..." placed in the Processing tab.
As input use the "Multiple input" for storing the list of raster files, see image below
And later ...
- 31.4k
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