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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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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0answers
10 views
Use of RGB images for plant health classification
GRVI is the greenness index of vegetation, which is certainly not the replacement of the NDVI. However, can anyone justify the use of GRVI from RGB images, for the classification of vegetation using ...
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1answer
40 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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1answer
25 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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29 views
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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1answer
82 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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44 views
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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97 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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119 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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1answer
67 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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1answer
148 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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1answer
131 views
How calculate 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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1answer
47 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 ...
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0answers
55 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 ...
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0answers
54 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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0answers
54 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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1answer
247 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 ...
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1answer
515 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 ...
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1answer
811 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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1answer
672 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
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2answers
93 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 ...
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0answers
113 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 ...
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1answer
388 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 ...
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1answer
99 views
How to classify vegetation in 500x500 m polygons in a very coarse way in QGIS
For a simple species distribution map for the Dutch Wadden island of Terschelling, I want to give each 500x500 m polygon (reference grid = EPSG 28992) a specific color that coarsly corresponds with ...
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0answers
85 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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1answer
141 views
Calculating area for range of values of spectral indices in QGIS?
How do I retrieve the area of a place which I've already calculate the NDVI index?
The thing is that I just need the area of the pixels that have values between 0.5 to 0.8 (It is a Landsat 8 image).
...
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2answers
203 views
Atmospheric effects on extracting soil from BSI index?
I need to extract soil from Bare Soil Index (BSI) using Landsat 8 and Sentinel 2 images in QGIS or IDRISI.
I was told to start with basic atmospheric correction of bands by finding in the histogram ...
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1answer
163 views
Using vegetation cover and DEM elevation data together
I'm using Terrain data (DEM) from USGS and I would like to build a map in which I can keep the information on the elevation in 3D and on the vegetation cover. I have obtained the 3D raster for the ...
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1answer
58 views
Checking Vegetation height accuracy in urban areas
I have digitized vegetation as polygons covering the canopy of trees in urban areas. Are there any suggestions to check the accuracy of height. I have been manually validating with visual checks, ...
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2answers
694 views
Finding min and max raster values using polygons in ArcMap?
I have a raster dataset that encompasses an area which has previously been classified into vegetation types. I have the classification polygons and want to lay them on top of a vegetation index image ...
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0answers
443 views
List of indices (e.g., NDVI) that can be calculated with satellite images [closed]
I'm looking for a list of published indices that can be calculated from satellite images and the corresponding formula for each:
Some indicies, for example, would be:
- NDVI: https://en.wikipedia....
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0answers
102 views
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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1answer
980 views
Calculation of average NDVI of area in QGIS?
I wish to calculate the average NDVI value of an area (polygon). Thus the average value of all pixel.
How can this be done in QGIS?
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1answer
363 views
Applying MODIS Pixel Reliability and Vegetation Index (VI) Quality mask for MOD13Q1 using ArcGIS Desktop?
I have some sets of MODIS MOD13Q1 data sets during March and December for year 2000 to 2015. I need to extract the NDVI and EVI for those two months from the entire 15 years.
How do I apply the ...
3
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1answer
391 views
Creating NRG Multiband TIF from single bands using QGIS?
I'm attempting to take 3 single bands (NIR, Red, and Green) and turn them into a single multiband tif image.
Someone working on the images was able to take this image which I merged...
And then ...
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1answer
215 views
Discrepancies in remotely sensed indices using Sentinel 2 Level 1C imagery
I am hoping to derive a variety of vegetation indices for grasslands in Peru using Sentinel 2 data for one cloud free image in June 2016. But most of my indices are not in the range of the index. For ...
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1answer
390 views
What are the spectral indices that use addition of Landsat 8 bands for finding vegetation?
NDVI is found out using the division of subtraction and addition of bands. Is there a simpler index for finding out vegetation(or other physical characteristic)? For example, DVI=NearInfraRed-Red is a ...
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2answers
480 views
What is the index formula to calculate water stress index using multispectral sensor (Red, Blue, Green, Red edge, NIR)?
I am having a multispectral sensor with Red band, Blue band, Green band, Red-edge band and Near-Infrared band. I need to find water stress using these bands, is it possible to find and if yes what ...
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1answer
155 views
How to represent seasonal variability in a single global NDVI map?
I have twelve monthly MODIS datasets for a 1 year period (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD13A2_M_NDVI&year=2015) and wish to combine all the data into a single map highlighting ...
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1answer
1k views
How to analyze Vegetation Index using Sentinel-1 SAR Imagery?
I am using the ESA open scientific data hub for Sentinel 1 SAR imagery (Interferometric Wide swath SLC VV polarization) and would like to know how to perform vegetation health analysis from this data? ...
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0answers
180 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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1answer
122 views
About PolSDP software for SAR processing [closed]
Can anybody help me to find PolSDP software or provide a link from where I can download.
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1answer
2k views
Tutorial Vegetation Condition Index
Anybody here can help me regarding calculating Vegetation Condition Index (Kogan,2004) for Landsat?. Specially facing problem in NDVI_max and NDVI_min; which should be maximum and minimum value?
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4answers
2k views
Alternative vegetation indices
I have been using NDVIs with limited success to identify trees in the central Great Plains region of the USA. The problem I have been encountering is that reflectance from farm fields/pastures have ...
