Questions tagged [ndvi]

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

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3
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1answer
163 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 ...
1
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1answer
237 views

Pixel based 10 year NDVI time series

I would to do pixel based 10 year NDVI time series analysis using MODIS data. I’ve 3 seasons in a year. Should I average all values in the study area per season?
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0answers
62 views

Find densest point in satellite agriculture map [closed]

I have a .tiff image file with 3 bands. I want to write a program, (python opencv?), that will find the first N densest points in the region. Densest, meaning the point with the most of its own ...
0
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1answer
723 views

NDVI anomaly calculation in ArcMap 10.2

I am trying to calculate NDVI anomalies for three years satellite images in ArcMap 10.2. I am doing it by using formula: [{(NDVImax_2000) - (mean_NDVImax)} / (mean_NDVImax + NDVImax_2000)] * 100 I ...
1
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1answer
314 views

time-series analysis

I have 46 MODIS NBAR images of the same area (time-series). How can I get seven (1 for each band) multilayer (46 layer) images, for the further FastICA analysis? According to the results of the paper, ...
2
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1answer
141 views

Is there a standard color palettes for the spectral indices?

Is there a standard color palette (or most commonly used in publications and other materials) for the spectral indices?
2
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1answer
265 views

How do you convert a raster of digital values of ndvi to an index of NDVI?

I have a raster of the Mean May Normalized Difference Vegetation Index (NDVI) that is a composited measure of VGT daily images, acquired between 2000 and 2009 in May, using the Mean Compositing ...
2
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2answers
209 views

Comparability of Landsats

I have collected data (spectral bands) from Landsat 4-5 and Landsat 8. I was calculating NDVI when I noticed that the two Landsats have different band numbers designated as Red and Near Infra Red (...
3
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1answer
428 views

QGIS raster calculator: difference gives NaN for Landsat 8 scene

I'm strugling with the QGIS Raster Calculator, trying to get a NDVI image from a Landsat 8 scene (path 222, row 84, date 2015-11-15). The problem is, I'm consistently getting NaN values for all the ...
2
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1answer
237 views

GRASS 7 raster map calculator

I am new to GRASS and am trying to use it because I can't afford the Spatial Analyst extension in ArcGIS. I am trying to remove all of the values in a NDVI raster less than some value to exclude ...
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1answer
858 views

Remove raster pixel in R

This is the 32 year trend NDVI (raster data) I would like to remove the green grids data by using R (the green pixel value is larger than 0.03) and this one is R code that i use but i cannot remove ...
2
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3answers
233 views

MODIS temperature and NDVI data?

hope anyone could give me some hints here. I tried to download free MODIS data from their page(resolution 500m, 1km). Im interested in NDVI and temperature data. But when i load the hdf files into my ...
0
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1answer
64 views

AVHRR 1 km Coterminous US Server Location

I want to download a signficiant amount of AVHRR data directly from a FTP server... the problem is I'm having a really hard time finding the server location. I don't want to use EarthExplorer because ...
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0answers
30 views

What indices could is use for coastline extraction using rapideye imagery

I am currently writing a proposal to get RapidEye imagery for my master thesis. In this proposal I am trying to explain what I am doing. Except NDVI/NDVI-RedEdge and NDWI, can anyone suggest some ...
2
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1answer
1k views

How to remove clouds with the cf_mask.tif file provided from landsat 8 surface reflectance data?

I just downloaded my first group of landsat 8 surface reflectance data files. In this package contains sr bands 1-7 (I hope to use some of these to create an NDVI) as well as numerous files called: ...
3
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0answers
695 views

How to create an annual NDVI from Landsat 8 imagery [closed]

I am relatively new to GIS. I am studying wildlife (I have collar data that lasts a year) and my supervisor and I would like to create an annual NDVI map for my projected area. I was able to ...
2
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2answers
111 views

How to extract clear cut areas from dried trees in forests

I have 40 cm resolution aerial image with visible and near-infrared bands. Purpose is to extract dried trees in forest. I used multiresolution segmentation algorithm to extract individual trees and ...
3
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1answer
196 views

Temporal spectral analysis in order to differentiate agricultural/croplands from natural/semi-natural grasslands using remotely sensed data

I am working on a critically endangered bustard species in India (Houbaropsis bengalensis). I need to prepare a land cover map of its 'suitable' grassland habitat across its distributional range. I ...
6
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1answer
2k views

Python script for calculating NDVI in QGIS

I am looking for developing python codes mainly for working with raster data, in particular satellite imagery from Landsat. I am familiar with GIS and RS and I usually work with QGIS, but I am new in ...
1
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1answer
546 views

Calculating maximum value in Raster Calculator of ArcGIS for Desktop?

I have MODIS NDVI data of four months and I have to calculate NDVImax. I am using the Raster Calculator of ArcGIS and have been using various algorithms like [MAX ("june2000", "july2000" , "...
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1answer
207 views

Doubt in MODIS NDVI range [duplicate]

MODIS-NDVI product MOD13Q1 shows range from -1986 to 9976 but NDVI ranges from -1 to 1. What these value means? What do I need to do as corrections? I have attached an image showing MODIS-NDVI ranges ...
6
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1answer
2k views

Difference between Landsat 7 and Landsat 8 TOA reflectance computation

In section 3.1 of this article it is explained how the Top of Atmosphere Reflectance for Landsat 7 and Landsat 8 are computed. The equation for Landsat 8 is not mentioned explicitly, but can be found ...
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1answer
272 views

Higher NDVI than SAVI [duplicate]

I have calculated NDVI and SAVI for landsat-8 image. But I am getting higher value of NDVI than SAVI Can you tell me reason for this NDVI=0.46 SAVI=0.34 Specific band pixel values are toa b4- 0.130 ...
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0answers
194 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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2answers
452 views

QGIS NDVI Spatial Analysis

I have an NDVI raster that I would like to reclassify into some arbitrary bins i.e. all values between 0 - 0.2, 0.2 - 0.4 etc. for spatial analysis. Could anyone advise how to: 1) reclassify a ...
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0answers
140 views

Radiometric calibration NDVI values in Excel

I´m doing NDVI analysis, but i forgot to do Radiometric calibrations in QGIS. So the NDVI values in my excel table are in DNs. Can I do this calibration directly in excel?
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1answer
149 views

Matching Decedal Average NDVI and Worldclim Data

Ive never used NDVI (or EVI) datasets in R. Does anyone have any resource I could use to access a decadal average NDVI dataset for the globe. It would be preferable if this dataset was also comparable ...
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0answers
789 views

Downloading NOAA AVHRR NDVI using R

I am using the gimms package to automatically download NDVI data from 1981-2013. The code is provided here. The data is available here. However, after running it shows that data has been downloaded ...
2
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0answers
78 views

Extract Mean Raster Value from multiple raster files into Excel

I have a series of non-orthorectified raster files containing NDVI information. I would like to extract the mean value from each raster so I can see a summary of each raster image name and the ...
3
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1answer
1k views

Converting Worldview 2 imagery to TOA reflectance for Vegetation Change detection in ArcGIS?

I am working on a change detection study to look at effects of herbicides on vegetation growth. Therefore I have Worldview 2 (4 band +pan band) imagery for two subsequent years that I would like to ...
0
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1answer
392 views

NDVI colour scheme for ArcGIS

Does anyone have a download link for the NDVI colour scheme to use in ArcGIS for Desktop? I am looking for MODIS mod13 data and cannot find an appropriate colour scheme in the programme.
3
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1answer
318 views

Extracting NDVI using QGIS from multiple images to Excel?

I created 25 images in QGIS. Each image has different information about the NDVI of the area. How can I extract mean, max, and min information about the NDVI from each image and put it in Excel?
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0answers
85 views

Where can I download NDVI or landsat images of south china that isn't in an .img file format [closed]

Everything i seem to find is an hdf file and i can't open it in erdas. so is there a way to convert it to open in erdas or do i need to find somewhere else, earth explorer and glovis are the two ...
3
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1answer
2k views

How to smooth NDVI raster (Sentinel 2-A image) in ArcGis?

My question is regarding the final display of a NDVI raster. I currently work with ArcGIS Desktop 10.2.2. When I work with Landsat images (the image is loaded as composition through the MTL file, ...
3
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2answers
2k views

Classify forest with NDVI from Landsat 8 and 7

I'd like to calculate the NDVI for multi-date satellite images of Landsat (7,8) to perform a change detection on the deforestation of the Amazon rainforest. I already acquired surface reflectance ...
2
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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?
0
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1answer
188 views

Obtaining NDVI data from red-edge imagery?

I am working with an aerial image containing three spectral bands (blue, green, and red-edge). I can obtain an NDVI image with the imagery using Erdas Imagine, but I do not know which bands Imagine is ...
3
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0answers
37 views

Creating coloured map from Excel using ArcGIS for Desktop? [duplicate]

I have an Excel file with some data and I want to create a map and present data with colours. I do everything well except for I present my data with dots. Instead, I need to cover the free space with ...
2
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1answer
386 views

PostGIS Raster performances

I ingested two Landsat images into PostGIS database using : raster2pgsql -I -C -s 28356 -M -t 100x100 LS7_20150425_B40.tif public.red | psql -d postgres -U postgres raster2pgsql -I -C -s 28356 -M -t ...
5
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1answer
1k views

Rescaling NDVI values 0-255 to [-1;1] using ArcGIS Raster Calculator?

How do I rescale NDVI values that are 0-255 to -1;1? I'm trying to do it in ArcGIS Desktop.
0
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1answer
56 views

Extracting NDVI for large extensions using ArcGIS for Desktop?

I'm trying to calculate NDVI in ArcGIS for Desktop using MODIS to entire neotropical region but I can't find MODIS values for all neotropical. Instead, I foud only for small regions. Does someone ...
2
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0answers
193 views

16-day-MODIS NDVI values seem to be wrong compared to my soil moisture ground data!

I'm using MOD13Q1 product of MODIS for estimation soil moisture. As I know, this product is made up of the maximum value of NDVI of each pixel over 16-day calculated NDVI values. The problem is that ...
1
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1answer
965 views

NDVI values for MODIS images [duplicate]

I have downloaded NDVI MODIS 500m image i.e. MOD13A1. From the hdf format that i got i converted them into tif format using the HEG tool. The images that i got some are showing pixel values -32767 to ...
1
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1answer
409 views

Resampling 30 m NDVI to 5 m in ArcGIS [duplicate]

Is there any easy way to resample 30 meter NDVI from Landsat 8 images to 5 metres? I use raster to point and the interpolation of point to raster using Kriging method. I know that it may not be a ...
2
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1answer
328 views

NDVI in ENVI: Output format issue

I am working on NDVI in ENVI... the output file is in Envi Standard format... I required it in Envi Classification format, which can be done through Envi Edit Header tool... This requirement is for ...
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0answers
1k views

Histogram matching of two NDVI images

I have two Landsat 5 NDVI images (Surface Reflectance products) from the same period of the year (only a few days apart), but one is from the 1980s and one from the 2000s. I am trying to do a change ...
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0answers
74 views

How to create a map showing NDVI result in erdas?

I'm using Spot 5 image to run an NDVI analysis. The band that I used in processing is 4,3,2. The area was 80% covered by mangrove. My problem here how can I create a map to show or present the result? ...
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1answer
3k views

Using R calculating NDVI [duplicate]

Is there any function to calculate statistical NDVI in landsat8 package
0
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1answer
867 views

Changing the the range for MODIS NDVI

I need to get MODIS NDVI (MOD13A3), but output from EarthExplorer or Daac2Disk HDF format is a numerical range is -2000 to 9996. But I need for futher work basic range -1 to 1. Is there any ...
0
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0answers
484 views

Landsat 8 - NDVI Global Servises - Clouds

I'm looking for Landsat 8 NDVI Global Services, like ArcGIS Online, but including scenes with the high presence of clouds (50-95%). Fresh scenes with clouds needed because they can contain the areas ...