Questions tagged [ndvi]
Normalized Difference Vegetation Index is used to quickly identify vegetation and its condition in remotely-sensed data.
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No features in Sentinel 2 Level 2A Harmonized dataset
I am running into a problem I am trying to calculate MCARI and NDVI from the Sentinel 2 Level 2A dataset and it doesn't have any feature for the data range from 2017 to Dec 2018. Can anyone advise me ...
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Inverted NDVI output using ArcGIS Pro
I am trying to perform an NDVI on multiple rasters in a folder. As I understand it, an NDVI output has a range of values from -1 to 1. Values 0 and above should represent vegetation and values below ...
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xxx.reduceRegion is not a function [closed]
I'm new at coding in Gee and I have a "xxx.reduceRgion is not a function" error (line 94).
The overall task is to extract 4 different indices from Sentinel-2 images for 40 sites in Canada, ...
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Exporting NDVI data by postcode
I am trying to export Landsat NDVI data by postcode. I am new to this game and don't really know how to go about it but have seen similar things done in some recent academic papers (https://journals....
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EVI2 calculation，Issues arising from collection 1 to collection 2
Old code:
var L5_EVI2= function(image) {
var evi2 = image.expression( '2.5 * ((NIR - RED) / (NIR + 2.4 * RED + 1))',
{
'NIR': image.select('B4'), 'RED': image.select('B3')
}
).rename('EVI2');
var ...
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Landsat 7 NDVI errors?
I calculated NDVI using a method from a previous question I asked. I forgot that Landsat 7 has errors following 2003. I don't mind running it again but is there ways to correct for this error?
# Start ...
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Sample NDVI time series for points and retaining the unique point ID in Google Earth Engine
In Google Earth Engine, I have a feature collection of points with one column that is the "Feature Index". Now I am extracting time series for every point. How can I retain the "Feature ...
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What's the difference between collection2 of Raw Scenes and TOA
I'm a beginner of GEE, I can't distinguish the difference of Landsat collection2 of Raw Scenes and TOA, such as 'USGS Landsat 7 Collection 2 Tier 1 Raw Scenes' and 'USGS Landsat 7 Collection 2 Tier 1 ...
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Can't calculate NDVI from Landsat 8 data
I have acquired Landsat 8 data from earthexplorer; I got band 5 and 4 only as they are the necessary bands to calculate the NDVI. I've followed every YouTube video and article online with no chance of ...
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Error trying to calculate the NDVI of about 20 cities in the USA in GEE
I am new to GEE. I am trying to calculate the NDVI of about 20 cities in the USA. However, I keep getting this error:
Error: User memory limit exceeded. (Error code: 3)
I don't know how to solve it. ...
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Calculating NDVI using OrfeoToolbox
Platform: Windows 11
Aim trying to achieve: I have downloaded some multispectral test data from OpenDroneMap (ODM) forum. The data is captured with DJI Mavic 3M. What I want is to analyze NDVI, NDRE, ...
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Error generating chart: Image.parseExpression: Expression contains undeclared variables: [max] for vci, and tci [closed]
I have a problem creating the chart and there is error message expression undeclared variables
var geometry =
/* color: #d63000 */
/* displayProperties: [
{
"type": &...
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How to the image date/ metadata used when using the .median filter in GEE?
I am processing LST, NDVI, NDBI, & UHI data in a 1 year period. I used the .median filter function for filtering the dates.
My question is, how do I know what images to use? I've tried the ...
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Does MODIS dataset (MOD09GQ) require atmospheric correction to calculate NDVI?
It took a dataset of satellite images with a high frequency of reception (1 day) to work. The work consists in studying the change in the NDVI coefficient at a certain site during the year.
I took ...
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Cannot export NDVI map to google drive on Google Earth Engine
I am trying to export an image of NDVI before a wildfire to my Google Drive but it keeps failing and I am unsure of what the issue is.
the variable burntsite is a polygon I drew.
var prefire = ee....
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