Questions tagged [ndvi]

Normalized Difference Vegetation Index is used to quickly identify vegetation and its condition in remotely-sensed data.

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90 views

Is it possible to create an average image of the analyzed period after the removal of the clouds to fill the flaws in the images?

// study area var local = ee.Geometry.Rectangle([-42.2974, -20.5299,-40.9406, -19.1815]); Map.addLayer(local); var landsat8 = ee.ImageCollection('LANDSAT/LC08/C01/T1_SR') // Fmask classification ...
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1k views

How to apply a Cloud Mask in Google Earth Engine? (Landsat 5 TM 8-Day NDVI Composite)

I need to download ndvi values for some pixels for 2000-2001 using the Landsat 5 TM 8-Day NDVI Composite, but since there is no quality band as in mod13q1 there's no way to filter by quality. ...
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185 views

What bin value does QGis Histogram uses?

I have some single-band rasters (NDVI) on Qgis, for which I can obtain their distribution histogram by going to Right-click > Properties > Histogram Tab > Compute Histogram. This is an ...
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1answer
371 views

Black vertical lines on exported image from Google Earth Engine

I tried to export the NDVI obtained from the Landsat 8 Surface Reflectance Collection in Google Earth Engine and I keep on getting black lines in my final export. Everything looks fine when displaying ...
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1answer
108 views

interpreting Normalized Differentiated Bareness Index and Normalized Differentiated Impervious Surfaces Index? [closed]

I've tried looking for various sources to help me interpret NDBaI and NDISI indices but I've not found anything particularly helpful. Does anyone know how to do it or have any literature that might ...
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2answers
48 views

NDVI image contains 500 cells or more using ArcMap

I want to make a map that shows my NDVI image (with 6 classess, natural breaks that I reclassified already)) that only contains zones with 500 cells or more and that are color coded to the area of ...
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3answers
218 views

Loop using variable - r.mapcalc GRASS GIS

I am doing threshold classification of NDVI rasters. One equation looks like that: r.mapcalc 'prog_r43_n65=if(ndvi_r43_n65>=0.6,1,2)' Now I want to make a loop for more than 2000 rasters, so I ...
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1answer
284 views

Computing NDVI - Repeated calculation error message (Google Earth Engine)

I am doing simple calculation for NDVI using Landsat 7 TOA Reflectance (Orthorectified). Landsat seven has the following bands: B1-Blue, B2-Green, B3-red and B4-nir. I used the following code: //...
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1answer
220 views

Removing Clouds From (Landsat8) NDVI Imagery with ArcMap? [duplicate]

I recently was able to generate NDVI images from Landsat 8 using Arcmap. My end goal is to run some zonal statistics over specific neighborhood polygons, however with the cloud values (ranges of 0.002&...
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509 views

Difference between gdal_calc and QGIS raster calculator

I am hoping someone can help me with an issue I am having with gdal_calc. I am looking to create NDVI rasters from 4 band 8 bit ortho tiles. I have processed the tiles using the following calculation: ...
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2answers
2k views

Export time-series MODIS 16 Day NDVI and EVI Data on Google Earth Engine [duplicate]

I want to extract every single MODIS 16 Day NDVI and EVI Data image on a particular area from 2000 to 2016. I was able to filter image collection but I do not know how to export every single image on ...
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194 views

ModisDownload - doubts when using MRT tool

I am using the incredible MODISDownload function from the rts package in R to download NDVI data on vegetation index in Africa. I have two questions. I am using the latest version of the package ...
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1answer
111 views

Exporting NDVI as .TIF using ArcPy?

Here is my code so far: import arcpy from arcpy.sa import * arcpy.CheckOutExtension("Spatial") workspace = arcpy.env.workspace = "C:/Users/KJanus/Desktop/Intro_ArcGIS/RasterData_Lab6" arcpy....
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1answer
593 views

Monthly GIMMS NDVI time series [closed]

I need to create a monthly NDVI time series from GIMMS in GEE (i.e. from January 1981 to December 2013) from the sum of fortnight values (or mean). I've been trying to create a function to do so, but ...
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1answer
432 views

how to create C factor (RUSLE) map by using NDVI values?

I have a basic knowledge of GIS and arcgis sofware and I need to generate C factor (cover management factor of RUSLE) by using NDVI values. I know there is an exp formula but I dont know the steps to ...
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2answers
561 views

Calculating NDVI using Landsat 8- Cloud/Atmospheric Correction

System: Windows 7 Software: Arcmap 10.4.1 Data: Landsat 8, NDVI calculations I am attempting to calculate the NDVI values over my state over a period of 3 months. Naturally, there are going to be ...
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2answers
422 views

NDVI data for UK?

I am looking for monthly composite NDVI data for the UK between 2000 and 2013. The resolution is not so much of an issue. I am struggling to find relevant data and images for further processing in ...
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1answer
167 views

Make raster layer in ArcPy?

I am trying to calculate NDVI from rasters that I've downloaded with download rasters, clipping them with some features (selection_feature) that I'd split from an original archive. I am a begginer in ...
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1answer
255 views

Landsat level-2 NDVI valid range with saturation

I have Landsat level-2 NDVI tiles I am using in ArcMap 10.4.1.; however, the level-2 NDVI data in ArcMap ranges from -5,189 to +20,000. The spectral image product guide (which I've linked) says that ...
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1answer
159 views

Difference between types of Vegetation indices

I am currently comparing different types of Vegetation Indices, in this example I am using a NDVI formula and a TCARI formula. The NDVI result came out as expected with values ranging from +1 to -1. ...
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2answers
463 views

Using Landsat 5 TM 8-Day NDVI Composite?

I'm working in a project where I need the NDVI for some areas from Uruguay for the period 1988-1993, and I found this product "Landsat 5 TM 8-Day NDVI Composite" but I'm not sure of how it was ...
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1answer
2k views

Processing LANDSAT 8 data in R (using packages Raster, RSToolbox, etc.) in order to calculate NDVI and land cover classification? [closed]

I am analyzing several LANDSAT scenes from the LANDSAT 8 OLI mission (18 in total, all from Jan 2017 - cloud cover < 20%). I now want to calculate the NDVI and do some land cover classification on ...
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2answers
166 views

Is it possible to calculate NDVI using a landsat 8 .img file?

I have a mosaic image with this file extension (.img) When I use image analysis in arcmap.10.4 to calculate NDVI I get values the following values High: 3 Low : -5 NDVI values are supposed to be ...
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2answers
1k views

Calculate NDVI using ArcPy Spatial Analyst

My goal is to calculate NDVI using map algebra syntax. import arcpy from arcpy.sa import * red_band_raster = (r"C:\B3.tif") nir_band_raster = (r"C:\B4.tif") #Calculating NDVI float raster ...
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2answers
974 views

Planet NDVI calculation: ModuleNotFoundError: No module named 'rasterio'

I'm performing NDVI calculation on a Planet Scope 4 band image as per Planet's documentation The following block of code is what I wrote: Extract band data from original image in working directory ...
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1answer
285 views

Landsat Collection 1 Level-1 or Landsat Collection 1 Higher Level?

I want to use NDWI and NDVI index in my study for a time-series analysis using all products available (Landsat 5,7 and 8). Can I use the product Landsat Collection 1 Level 1 for my analysis or ...
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1answer
224 views

identification of Forest cover area by using eCognition Software

How to find forest cover area by using eCognition software? I'm trying to find vegetation by using NDVI in the ruleset but it takes vegetation too with the forest. Can I use any other filter along ...
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1answer
229 views

How to convert NoData values to other values for raster data?

I have a NDVI map from MODIS data for my AOI. When classified, i noticed that few of the pixels appear in " white" color and show no value. How do i classify these pixels and attache an appropriate / ...
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1answer
313 views

Why getting wrong NDVI values resulted from scaled reflectance in ArcMap?

I have made atmospheric corrections to my Landsat 8-OLI raster using 'ENVI FLAASH' having surface reflectance values scaled between 1-100. In ArcGIS I am using simple expression to compute NDVI ...
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0answers
193 views

Opening ENVI files in ArcMap?

I have calculated NDVI (vegetation index) in ENVI 5.2 and I saved it in TIFF format. Now I am trying to open it in ArcMap, but its not opening properly. The image is total black and the values are ...
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2answers
2k views

Do clouds reflect NIR/Red bands

When using Landsat 8 imagery to calculate NDVI, will the NIR and Red bands be affected by cloud cover? In other words, will clouds produce a wrong NDVI calculation?
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1answer
99 views

Cleaning up polygon generated from NDVI raster

So I have NDVI raster files for about 1000 acres of vineyards we manage. What I have done is created a model that takes the NDVi raster, reclassifies it to isolate out the areas of high vigor, then ...
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269 views

Stretching (rescaling) Raster (NDVI) Values between -1 and 1?

I am trying to equalize NDVI values for the same area temporally. For example 2014 LS8 NDVI values between -.12 and .007 while 2011 LS5 values between -.33 and.77. I would like to equalize each raster ...
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1answer
87 views

NDVI usage for ArcCollector and Crop Yield

So my question is as follows: I am a GIS tech for a large vineyard management company. Every year a real struggle of ours is getting a crop estimation (with +- %15 accuracy, company wants it to be +-%...
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517 views

How to export image on google earth engine for large area?

The area that i have been work have about 159695,938 km² and I am mapping the deforestion on this with NDVI. I had to use 2 years to remove all the clouds (eg. 2015-01-31 , 2016-12-31) using a reducer....
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1answer
2k views

Mask clouds in an ImageCollection google earth engine

Is It possible to create .median() Surface Refletance image (landSat 8 RS) without clouds before calculating the NDVI in goolge earth engine? I need to work with a year (eg. 2016-01-01, 2016-12-31), ...
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2answers
656 views

Calculate NDVI image from R and NIR channels and rescale it to 0-255

I have images of plants taken in Red(R) and Near End Infrared(NIR) field, I calculate the NDVI image per pixel using the below formula, NDVI = (R-NIR)/(R+NIR) , for all pixels, I get a range ...
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1answer
1k views

Mask clouds in LandSat 8 surface refletance image

I would like to know how to remove the clouds in a ImageCollection of LandSat 8 Surface Reflectance (SR) image and create a single image without clouds using google earth engine, to calculate NDVI. I ...
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1answer
410 views

calculate NDVI for several images

I want to calculate NDVI for 50 Landsat 7-TM images . I have done a stack layer for each band of 50 images using envi software and then calculate NDVI for the stack of two bands demanded in NDVI ...
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2answers
580 views

Analysing Landsat images using ERDAS IMAGINE and ArcGIS

I am trying to use the Theil-Sen analysis on the Landsat images to compute vegetation indices, help me figure out how to come up with the median from the Theil-Sen equation in ArcGIS, ERDAS IMAGINE or ...
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1answer
749 views

Image segmentation

I am performing a segmentation on an NDVI using the OTB mean shift segmentation on QGIS 2.18. The size of the image is about 15000*15000 with one band only and 8-bit. Since I do not want to use ...
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1answer
251 views

Landsat NDVI batch calculation

I want to perform a time series analysis of Landsat NDVI. I could not find a prepared product online (except in GE Engine but it is no possible to download). Thus I would like to calculate the NDVI in ...
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0answers
123 views

Creating Geotiffs MAPIR plugin? [closed]

I am trying to create Geotiffs on QGIS. I have images(RGB) from a dji phantom 4 pro and images(raw) from a MAPIR ndvi camera. However the two cameras used are not linked. I wanted to know if you ...
3
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1answer
169 views

How can we calculate the area of dense and sparse vegetation from NDVI image in QGIS?

I'm trying to obtain values of area covered by dense and sparse vegetation through NDVI classification. I'm using QGIS (2.18), ERDAS 2014 and ArcMap.
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1answer
4k views

Using a fixed palette range to plot an NDVI raster in R

I would like to plot an NDVI raster with rasterVis packages using the normalized colors from red to green. I don't understand how fix the color scale from 0 to 1 even if my raster value are between 0....
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0answers
48 views

What is the best way NDVI can be used for assessment of remediation level of ecosystem (after nuclear accident)?

I am thinking about ways to assess efficiency of various bioremediation methodologies and self-remediation of an ecosystem polluted with nuclear waste. I would like to use NDVI as an assessment ...
2
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1answer
79 views

Is it rational to compare vegetation indices derived from different Landsat sensors?

I am using images from two different sensors, Landsat 8 OLI (January 2017) and ETM+ (January 2007) to compute various vegetation indices. These indices involve RED and NIR band to scale vegetation ...
3
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1answer
2k views

Unable to create NDVI image using Python gdal package

I have Python 3 and all GDAL bindings installed on my Windows machine, so that when I run this: import numpy as np from sys import argv from osgeo import gdal, gdalconst I get no error messages. ...
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3answers
870 views

Processing landsat 8 to make NDVI in R

I want to do the NDVI with images landsat 8 in R, radiometric correction, radiance and reflectance, I make it from the models of the USGS (model here) But taking the image (ND) for the calculation of ...
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0answers
275 views

QgsRasterFileWriter.writeRaster() is crashing python program

I am doing ndvi analysis on a farm image. After ndvi I need to convert the image into Singleband pseudocolor image using following python code. def calculate(): file_name = CUR_DIR + "\...