Questions tagged [evi]

The enhanced vegetation index (EVI) is an 'optimized' index designed to enhance the vegetation signal with improved sensitivity in high biomass regions and improved vegetation monitoring through a de-coupling of the canopy background signal and a reduction in atmosphere influences.

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34 views

stack() in R does not include all .tiff files in my directory

I am trying to perform stack() in R using enhanced vegetation index (EVI) time-series maps but it doesn't include all the .tiff files in my directory. Here's the list of files when I dir(files.evi): ...
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1answer
30 views

Why mNDWI can detect the shallow water area but ignores the deep water area?

I'm using Landsat 8 in Google Earth Engine to detect the water body in Jiangsu and Zhejiang area, China. The formula is: mNDWI = (Green-SWIR)/(Green+SWIR) I applied this formula to GEE code, and it ...
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1answer
56 views

Calculate water frequency in Google Earth Engine based on time series?

I have the Landsat 8 images cover southern Florida during 2017 (from Jan 1st to Dec 31st), with the cloud, scan edges and other bad observation pixels eliminated. I have also calculated several ...
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21 views

Format GeoJSON use Join method before export in Earth Engine

After filter an LANDSAT-05 for an small area var Collection = function(pixel) { var colForPixel = ee.ImageCollection('LANDSAT/LM05/C01/T1') .filterBounds(pixel) .filterMetadata('CLOUD_COVER','...
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1answer
31 views

How to compute the conditional function and output binary image in GEE?

I am now using Google Earth Engine to process the Landsat 8 images. Now I have calculated NDVI, EVI, mNDWI and generated some maps. I am now want to generate a function based on those indices values, ...
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18 views

Getting out of range output for EVI calculation based on Landsat 8

I will be using this stuff for an MSc project where I am looking at changing EVI over a four year timeperiod in 4 sites in the Amazon to look at changing rodent species abundances. I have got to the ...
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1answer
44 views

Why is the difference between 005 and 006 versions of MOD13Q1 data?

I tried to repeat a project that used EVI in MOD13Q1. I failed and found that the project used the 005 version of MOD13Q1, and I can only download the 006 version on NASA's ftp. I compared the 005 ...
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44 views

Why do I get different values in QGIS while calculating EVI for Sentinel2 images?

In my thesis I investigate vegetation change in Hungary. I downloaded some Sentinel 2 images from: https://scihub.copernicus.eu/dhus/#/home I used L1C and L2A pictures. During my work I transformed ...
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1answer
139 views

Obtain monthly and yearly average values of EVI using MODIS data on Google Earth Engine

I am currently trying to export and obtain rasters of EVI for: Every month of the year across 2000 to 2018 ie. If January has two MODIS EVI images, I would like to take the mean of the images for ...
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158 views

Calculate stats with GDAL Python or rasterio for each bands [closed]

I have MODIS EVI file stacking with 10bands. I use Python 3 in Spyder. I'm trying to rastersize shapefile and do mask to my MODIS EVI. This is my script : import os import glob from osgeo import ...
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1answer
122 views

Is there a limit to the number of raster layers in Raster Calculator?

I have 16-day Enhanced Vegetation Index (EVI) images for an area across roughly 10 years. 244 images in all. I would like to average these over the time period to get an average EVI value. Is there ...
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1answer
382 views

Plot times series for stack raster based on a polygons in my area

I am using R language and I would like to create a EVI MODIS time series plot, EVI vs time. I can did method to create a raster stack and plot the average EVI of the total area over time. But I ...
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2answers
228 views

Faulty Landsat 5 and 7 NDVI/ EVI archives in Google Earth Engine

For my research, I need to use NDVI or EVI datasets in Google Earth Engine. I found Landsat 5 and 7 datasets (8 day, 32 day, anual) for both. However, no matter which combination of datasets and dates ...
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1answer
102 views

Visualize polygon above the image of EVI index in R

I have MODIS images for the EVII index, with a polygon shapefile for specific areas in my area : files MODISEVI MODISEVI all polygons polygon The images of NDVI and the polygons have the same ...
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1answer
105 views

EVI2 value calculated from MODIS MOD09Q1 not bounded by -1 to 1

I'm trying to derive from MODIS 8 day composite MOD09Q1.006 product My formula follows the standard interpretation: EVI2 = 2.5(NIR-Red)/(NIR + 2.4*Red+1) I already know that MODIS bands for NIR ...
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1answer
452 views

googleearthengine - Code to calculate EVI having rendering issues

Below is the link of my code to calculate EVI in Google Earth engine. It is not giving/rendering color according to the color palette! Please help me in this regard. https://code.earthengine.google....
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1answer
262 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
289 views

Troubleshooting downloading MODIS NDVI Data in R

I am trying to download MODIS Data from 2000-2018, however I am encountering some difficulties. Here is my script MODISoptions(localArcPath = "/Volumes/myserver/MODIS/data", ...
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199 views

Raster calculator with EVI in ArcGIS

I'm trying to calculate EVI in Arcmap using raster calculator. I put in this calculation 2.5 * ((Float("Band4") - "Band3")) / (Float("Band4") + 6 * "Band3" - 7.5 *"Band1" + 1)) and the output is ...
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127 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
148 views

Predicting Enhanced Vegetation Index using Random Forest in R [closed]

I am a master's student and I am trying to use radar observables derived from SAR imagery to predict Landsat 8 Enhanced Vegetation Index (EVI) for different seasons. I have extracted EVI and various ...
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62 views

Unable to produce tif files from two stitched modis tiles, i could not extract my bands of interest which are EVI and pixel reliability

Hi i am trying to stitch two modis tiles and also extract my bands of interest which are EVI and pixel reliability. the steps i took are as follows. loaded the files into ModisTool selected my bands ...
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24 views

Creating EVI from sentinel2 image using ArcMap? [duplicate]

I am trying to calculate EVI from sentinel2 image using ArcMap and I used the following equation (2.5* (NIR/10000-red/10000))/(NIR/10000+(6*red/10000)- (7.5*blue/10000)+1) but I get very weird ...
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1answer
2k views

Calculating 2-bands EVI from Sentinel-2

I have been trying to calculate Enhanced Vegetation Index (EVI) using Sentinel-2 Level 1C imagery. I have atmospherically corrected the imagery (so the imagery is in BOA) but I can't seem to derive ...
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48 views

EVI not producing values between 1 and -1 Landsat5/7 TM ETM+

I am trying to do EVI in ArcMap 10.3. I have done the atmospheric corrections for all the bands needed but cannot get the values between 1 and -1. I have used the formula EVI = G *(Band4 - Band3)/(...
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1answer
151 views

How to extract EVI from MOD13Q1 with MRTBatch?

I want to extract EVI from Modis MOD13Q1 from some scene of images. I use ModisTool and MRTBatch. I have selected ONLY 250m_16_days_EVI as selected bands. All is correct until I save the parameter ...
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1answer
1k views

Calculating EVI from Sentinel 2 imagery gives difference in results between ArcMap & QGIS?

Though EVI coefficients have not been developed for Sentinel 2 imagery, I am using the same coefficients used for MODIS to calculate EVI for Sentinel imagery. I know that Sentinel 2 imagery is TOA ...
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1answer
694 views

How to compare EVI values with NDVI values?

I have been doing NDVI (Landsat 4-5) analysis for my research area for some time now. I recently decided to try out EVI (MODIS). But the EVI values I get are a bit different from NDVI. For example ...
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1answer
441 views

EVI coefficient values for Sentinel 2 image analysis

I am estimating EVI for Sentinel imagery and wanted to know the values of the coefficients L, C1, C2 etc. All the literature I have found use values from MODIS.
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1answer
2k views

GDAL not available in MODIS R package?

I am trying to analyze the MODIS EVI 250m, 16day dataset. I found the R MODIS package and am following the instructions here: https://conservationecology.wordpress.com/2014/08/11/bulk-downloading-and-...
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2answers
408 views

Using Con in Raster Calculator of ArcGIS for Desktop? [closed]

I have two images, "dvel.img" and "evi.img", and i want to extract water related pixels. The condition is: (("dvel.img" <= 0.05) & ("evi.img" <= 0.3)) I want to get an output by putting ...
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0answers
220 views

Calculating vegetation indices on pansharpened landsat 7 images [closed]

I have a problem with calculating vegetation indices like EVI, GSAVI, SAVI on Landsat 7 images after I done a Brovey Transform, Modified Resolution Merge and HCS transformation in Erdas 2013. My ...
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0answers
174 views

Application of a Piecewise Logistic Function to Extract Seasonality Metrics

I am working with 16-day MODIS EVI (satellite) data and I want to fit a Piecewise Logistic Function through my 23 EVI data values. The following formula is for the Piecewise Logistic Function: y(t)= [...
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1answer
3k views

EVI and NDVI range value

I've used a Landsat 8 image for vegetation analysis in an urban area. I've got a large maximum number of EVI value as shown in this image: Is this normal in calculating EVI and NDVI? Because I know ...
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0answers
107 views

VI Quality dataset in MODIS image [closed]

While importing NDVI dataset in ArcGIS should we also import the VI_Quality dataset ? If yes then how should we handle it ? and, if not, then for what it is there ?
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1answer
139 views

TIMESAT Land cover class

Is it possible to monitor phenology of only 2 land cover classes in TIMESAT? Example is corn and wheat for 7 years. Sowing structure of this crops changes every year, i.e. their location on an image ...
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3answers
2k views

How can I identify types of crops in agricultural raster dataset?

I have some 2014 MrSID files from the National Agricultural Imagery Program (NAIP) that I've converted to TIFF files. I want to use them to find the area of tomato farms in a watershed. I'm using ...
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2answers
883 views

calculate EVI for numerous tiles

I am trying to calculate EVI from MODIS data in Arc. I know how to run one raster group of 3 bands but don't know how to tell it to move on to the next group of 3 bands in that directory. Here is the ...
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1answer
2k views

Calculate EVI From Landsat 8 in QGIS [closed]

I have calculated atmospherically corrected reflectance values for Landsat 8. From that, I am getting correct values of NDVI in QGIS, but for EVI I am not getting the correct values. For some images ...
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1answer
1k views

Enhanced vegetation index using ENVI 4.7 bandmath

I computed Enhanced Vegetation Index using band math in ENVI 4.7 software. The expression used was: 2.5*((float(b1)- float(b2))/(float(b1)+ (6*float(b2)) +(7.5* float(b3)))) BYTSCL(float(b1), min = -...