All Questions
Tagged with ndvi sentinel-2
55 questions
1
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1
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36
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Calculate VIs in GEE over an image
In my study area shown in red line, I calculated an image of canopy height in GEE. I want to calculate NDVI, EVI, and other vegetation indices over this image. I know how to calculate the VIs in GEE ...
- 645
0
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1
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23
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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 ...
0
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0
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97
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TypeError: Image data of dtype object cannot be converted to float
The main functionality of the script is to extract GeoJSON data, load it into Earth Engine, retrieve Sentinel-2 imagery, calculate the mean NDVI, and visualize the NDVI for each GeoJSON feature.
My ...
- 131
0
votes
1
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27
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Extract, plot and export as a table a vegetation index time series from multipoint feature collection in Earth Engine
Reference is to a tread I posed years ago and was solved Extract pixel values from several bands of an image and export in a single table in Google Earth Engine
The challenge now is to create S2 NDVI ...
- 531
1
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1
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57
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Direct use of Sentinel 2 L2A imagery for vegetation analysis
I am working on my research to calculate the green vegetation in the study area using sentinel 2 L2A 10m resolution. Do I need to perform any correction or smoothing before analysis?
- 13
0
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1
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36
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Trying to create mask to eliminate false NDVI numbers in GEE time series analysis using Sentinel data
It keeps given me the error that ndvi.gte is not a function, I shared my code below:
var images = sentinel.filter(ee.Filter.date(startDate,endDate)).filterBounds(geometry)
print(images);
var ndvi = ...
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1
vote
1
answer
172
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Creating NDVI and Cloud Chart in Jupyter Notebook
I am trying to calculate NDVI and cloud pixel percentage. I have successfully done this but I am facing a problem in creating a chart of it in Jupyter Notebook, as I am new to Python so I tried ...
- 131
1
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1
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86
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Different NDVI Values for Landcover classes for Sentinel-2 and Landsat-8
I created a classified image of my study area using random tree classifier method as shown:-
Fig 1: Classified Image of Landsat-8
Fig: Classified Image of Sentinel-2
I now want to classify image ...
- 83
1
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1
answer
52
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Monthly sentinel-2 Max and Mean NDVI, and B9 values extracted to CSV
When trying to run this code I get an error:
Expected Type: Image(unknown bands) actual type:ImageCollections
I would also like to maintain the ID column to be the ID column in my shapefile(labelled ...
- 13
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0
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133
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Extracting NDVI time series(1 year) from Sentinel 2_SR for multiple points and creating CSV files for them
I have a shapefile that has 1500 points. I am trying to extract 1-year time-series NDVI values from Sentinel 2_SR for each point and export it to CSV with NDVI values date-wise and existing UID column ...
- 111
1
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2
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584
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I want to test the statistical significance of the NDVI change in R
I have 20 Sentinel 2 satellite data for the period from 2017 to 2020, with 5 satellite scenes each for the months from May to September, covering one vegetation season. I am interested in whether the ...
- 23
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2
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258
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Error while using Raster Calculator to calculate NDVI in QGIS
I exported 2 raster bands of Sentinel II (band 4 and band 8) to calculate NDVI (B8-B4)/(B8+B4), these 2 rasters are in EPSG:32630 - WGS 84 / UTM zone 30N. I'm currently using QGIS 3.26.1.
When I try ...
0
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1
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530
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Retrieving maximum NDVI for a year and associated date for each pixel in Google Earth Engine
I have been trying to generate a GEE script to generate two raster bands from a Sentinel-2 Surface Reflection collection.
The first band should have the maximum NDVI value per pixel for a whole year. ...
- 2,735
3
votes
1
answer
419
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Compute kNDVI using R
I am performing a small test to calculate the RBF-kernel NDVI (kNDVI). kNDVI is a nonlinear generalization of the commonly used Normalized Difference Vegetation Index (NDVI). It is a novel spectral ...
- 1,044
0
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1
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143
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Removal of atypical images from a time series NDVI sentinel-2 Google Earth Engine
I'm new to GEE.
How can I automatically remove by scanning sentinel-2 NDVI images from a collection of images, which contain outliers in their time series by taking into account the before and after ...
- 1
1
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1
answer
206
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Calculating 2022 NDVI time series
I calculated seasonal NDVI Time series (1 image for each season) from 2017 to 2022 using Sentinel-2 L1C images (which I converted to L2A using Sen2Cor), the first 5 years where ok, but the last 3 ...
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1
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1k
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Calculating average NDVI for specific months with S2A in GEE
I would like to calculate an NDVI average for only 3 months (april, may, june) for 5 years from the S2A image collection.
As a result I would like to create a chart with my 15 values and map an image ...
0
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1
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57
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Timesat 3.3 TSM_GUI "Error while evaluating Menu Callback" on Sentinel2 NDVI time series
I try using timesat on a 1 year NDVI time series (gapfilled) from Sentinel 2 imagery but I have an error message (see screenshot).
I converted each .tif NDVI image into flat binary format using the ...
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0
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3
answers
637
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Earth Engine GEE Abnormally low NDBI values derived from Landsat 8
I wanted to compare Landsat-8 NDVI and NDBI in a city using the codes below. I am using similar formulas. However, the NDBI value is abnormally low, compared to NDVI, and compared to raster calculator ...
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2
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0
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439
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NDVI from rescaled Landsat 8 L2 product is out of range
I need to use Landsat 8/9, level 2 products, to compute NDVI. I know that I need to scale band 4 and 5 before compute the index. Here there are the official scaling factors.
So, as example, I apply ...
- 970
0
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1
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106
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Trouble Converting gdal_calc.py output to Floating Point
I am new to coding.
I'm looking to create an NDVI on S2 data using gdal_calc.py in a Jupyter Notebook. I've downloaded imagery from GEE using code provided by the JRC, European Commission. I selected ...
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1
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1
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193
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If/else statement in Google Earth Engine doesn't give output desired
I am trying to make a correction for the NDVI index calculated from Sentinel-2 using GEE.
I found out that for pixels with NDVI meaning in the range (0.5, 0.6) it should be subtracted 0.122..., and ...
1
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1
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105
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Error generating chart: No features contain non-null values of "system:time_start" in generating chart of NDVI
I got this error when trying to produce a time-series chart of NDVI in Sentinel-2. I've already tried something like .copyProperties(image)".set('system:time_start',image.get('system:time_start'))...
0
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1
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426
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How to convert several raster files to binary raster using convert-geotiff tool without over writing
I have downloaded 12 raster files (for each month) from sentinel-2 for my study area. And then converted to NDVI(vegetation index). After that I used convert-geotiff (https://github.com/openwfm/...
- 9
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0
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188
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Why do I get wrong NDVI, EVI values in crop monitoring?
I have been monitoring agriculture lands with Sentinel-2 S2MSI2A data. I'm calculating NDVI and EVI for the vegetation. The NDVI values are slowly increasing because the growing crops which is look ...
- 21
1
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1
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979
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95th percentile greenest pixel quality mosaic - Sentinel 2 - instead of max
I am trying to combine the approaches suggested in the answers to this post - Google Engine - Make a greenest pixel composite for Sentinel 2 - to make a quality mosaic, based on the 95th percentile ...
- 149
1
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1
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950
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Calculating NDVI percentage change in QGIS
I am trying to show how NDVI changed between two periods using raster calculator in QGIS. I stumbled upon one example that was done in ArcGIS which i have no access to but would want to do the same in ...
- 39
0
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1
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622
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Exporting NDVI for multiPoint Geometry in Python API of Google Earth Engine
I have a list of mine coordinates and I want to export the mean NDVI of the region 5 km around the mine area. I was able to plot the mines, the region of interest and calculation of NDVI on map, but ...
0
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1
answer
1k
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Extracting time series from ImageCollection for multiple points using Google Earth Engine
I want to extract for each point of my shapefile the NDVI and the related time-series charts but I cannot understand how to extract values.
This is the code
// load the S2 dataset
var S2 = ee....
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1
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716
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NIR.subtract is not a function
I am trying to calculate Kernal NDVI (kNDVI) and the code keeps giving me this error.
The link to the code:
https://code.earthengine.google.com/24e8503ec2f264d0ffe0ba1bfe4c6353
/// adding shapefile to ...
- 69
0
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1
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1k
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NDVI time series with Sentinel-2 in Google Earth Engine
I want to calculate the time series of the NDVI with Sentinel-2 of a specific area of Australia.
I started from this code:
Time series analysis of NDVI using Google Earth Engine
Substituting Landsat ...
1
vote
1
answer
839
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Iterating to calculate mean NDVI and mask pixels having greater than mean NDVI value of each image in image collection using Google Earth Engine
I am working on Sentinel -2 image collection over my study region in Google Earth Engine. I can calculate Mean NDVI for an image using ee.Reducer.mean() and mask pixels using update mask .gt(mean ...
- 131
0
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1
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671
views
Add color table to NDVI using GDAL
I have an NDVI tif file that was generated from Sentinel 2A data using the gdal_calc method. I now want to add a red-green colour table to this file so that it matches the image below. I have managed ...
- 111
2
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1
answer
958
views
Computation timed out when exporting time series for a large number of locations from Google Earth Engine
I am trying to export Sentinel-2 NDVI time series for a huge number of fields (n>80000) to a csv file. However I got a 'computation timed out' error after 12 hours of running. Here is the code and ...
- 21
3
votes
2
answers
746
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Forcing y-axis range in ui.Chart.image.series()
I am harmonizing Landsat 8 and Sentinel-2 datasets for agricultural mapping purposes. When plotting the results using ui.Chart.image.series function, one graph shows the y-axis starting not at 0. For ...
- 568
1
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1
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930
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Sentinel NDVI timelapse
I'm trying to make a 5-year timelapse of monthly NDVI composites.
I apply a Hollstein mask, make composites and fill the masked area with mean NDVI pixels of the entire timeperiod.
Of course this ...
1
vote
1
answer
162
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QGIS Tools Change Raster Values
I am creating NDVI from Sentinel2 bands 8 and 4 on QGIS, using the raster calculator, but I need to convert the format or clip to a polygon beforehand, because my computer crashes if I try to perform ...
- 93
2
votes
1
answer
782
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Atmospheric correction of larger collection of Sentinel 2 L1C images (in Google Earth Engine) for NDVI time series [closed]
System: Windows 10
Software: Google Earth Engine browser, (QGIS, SNAP)
Data: Sentinel 2 L1C & L2A, NDVI calculations
I'm currently working on generating a NDVI timeseries in Google Earth Engine ...
0
votes
1
answer
867
views
Update image visualization parameters from slider UI elements in Earth Engine
I'm trying to change the visualization parameters (min and max) of NDVI images in an Earth Engine App with slider controls. The result is an animation of styled images.
The animation part works well, ...
- 91
2
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2
answers
2k
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Google Engine - Make a greenest pixel composite for Sentinel 2
Does anyone know how to do a composite of greenest pixel for Sentinel 2?
That is calculate the maximum NDVI for a Image collection, and then do a pixel-wise image stacking of the original bands (...
- 147
1
vote
1
answer
562
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Problem with Sentinel-2 NDVI export to TIFF in Google Earth Engine [closed]
I'm trying to calculate and export NDVI rasters extracted from Sentinel-2 using the script:
https://code.earthengine.google.com/a9247db3f03e9514eb0378d1f59e9447
Source code: Export images in google ...
4
votes
1
answer
2k
views
Create animation of NDVI from ImageCollection in GEE
I'm trying to make an animation of NDVI images from sentinel collection in order to see clearly variance in the field.
The first part of the code works with little error: "Layer name is not a string: ...
- 91
2
votes
2
answers
3k
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Make a Loop for Monthly NDVI in Google Earth Engine?
I've computed maximum NDVI for each month. but I don't know how can I write this code through a loop in Google Earth Engine?
code link: https://code.earthengine.google.com/...
- 311
1
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1
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261
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Can I use a greenest pixel or a no clouds Sentinel 2 for NDVI analysis?
Can I use a greenest pixel or a no clouds Sentinel 2 for NDVI analysis? I want to use it for extract spectral signature.
And now that I´m asking about it, I want to know if I can work classification ...
6
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2
answers
3k
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Data smoothing of Sentinel-2 NDVI time series chart in Google Earth Engine?
I am exploring Sentinel-2 time-series NDVI with Google Earth Engine. In another post I learned how to plot a NDVI time series chart.
I know that there are many smoothing methods for reducing NDVI ...
8
votes
1
answer
26k
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Creating Sentinel-2 NDVI time series chart in Google Earth Engine?
I am exploring Sentinel-2 time-series NDVI with Google Earth Engine.
In another post (here) I calculated and exported NDVI values from Sentinel-2.
Now I would like to create a NDVI time series chart, ...
4
votes
2
answers
3k
views
GEE Export.image.toDrive output not matching bounding box?
I am new to GEE and javascript. Copy-pasting here and there, I managed to put together this code that extracts NDVI from cloud-free Sentinel-2 images on GEE. I created a fusion table from a KML with ...
2
votes
1
answer
2k
views
Making subset of Sentinel-2 with rasterio?
I am looking for a solution to my problem with rasterio. I want to download just a specific part of the image from AWS based on lat lon coordinates. Rasterio offers a great tool (window) although it ...
- 23
1
vote
2
answers
2k
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Google Earth Engine API: How to select an image from an image collection based on NDVI value?
I want to select the image with lowest median NDVI to represent bare ground cover from Sentinel-2 image collection for my region of interest (<5% cloud).
I have a boundary file pre-loaded on ...
- 329
1
vote
1
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295
views
Create a grid of NDVI maps from different dates
I want to create a grid of 4 NDVI maps from different dates with the same parameters so I can check variance over a period
I tried to change an example named 'Linked Maps' in User Interface folder in ...
- 91