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Questions tagged [ndvi]

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

2
votes
1answer
948 views

problem of using TIMESAT to processing MODIS NDVI

I want to use TIMESAT software to analyse time series MODIS NDVI data. Firstly, I use MRT tool to mosaic,subset and project MODIS NDVI data and output data as GEOTIFF format, and save as ENVI standard ...
3
votes
5answers
6k views

Creating a Time series NDVI map

I would like to create a NDVI Time Series map? How do I do that? The one I probably would like to have similar like this http://proceedings.esri.com/library/userconf/proc02/pap0593/p05931.jpg I ...
2
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0answers
246 views

Comparing/Correlating NDVI Rasters with other index Raster

So, I've created two rasters. One for NDVI and one for another index for surface water from the same orthorectified World-View 2 image. I can visually see how the indexes are inversely proportional. ...
-1
votes
4answers
131 views

Why does ASTER create -0 to 0 instead of -1 to 1? [closed]

On my previous question on ASTER I need some more information on ASTER for time series analysis and I need to research on building NDVI because when I ran them for each ASTER. Most of them it came out ...
0
votes
1answer
958 views

How to extract NDVI values into polygon vector map with QGIS

I have calculated the NDVI values of a satellite image using the raster calculator. Now I need to have these NDVI values extracted into the attribute table of my polygon vector file. Is there a plug-...
1
vote
1answer
5k views

How to get percentage coverage of raster values in an overlapping polygon?

I have an NDVI image in ArcGIS 10.1 which is from -1 to 1. I have reclassified that image in 0 (range all negative value - non-green) and 1 (all positive value - green). I have overlayed a 'fishnet' (...
1
vote
1answer
3k views

How to process MODIS ndvi data using QGIS/GRASS/R?

I have MODIS ndvi data (MODIS_Grid_16 days NDVI) from the iberian peninsula (3 tiles), from February of 2000 to August of 2012 (really big data). I want to know how to deal with this kind of files. My ...
0
votes
1answer
3k views

How to create a loop in R to average ndvi raster time series?

I have monthly ndvi raster geotiffs for multiple years. I need to run a loop to get the average of each of these ndvi grids/rasters. Each of my ndvi rasters contains 143 pixels. I would like the ...
-2
votes
2answers
3k views

Which Bands from LISS III image are to be used for NDVI?

I have some IRS LISS III & IRS P6 IMAGES. What will be the correct bands to make NDVI image and how can I calculate from the data the amount of vegetation present or the change detection?
5
votes
2answers
883 views

Applying pixel reliability mask to time series MOD13Q1

I am working with a 23-band GEOTiff in which each band is a 16-day MVC MODIS NDVI image. The MODIS .hdfs include a "pixel reliability" image with the following values: [-1]: Fill/No Data-Not ...
1
vote
1answer
121 views

Sources for long-term NDVI datasets with coverage to west Asia?

I'm in need for long-term NDVI dataset for my research in bio-climatology, looks like GLCF GIMMS are no longer available online, any suggestions/workarounds to get the data.
7
votes
1answer
5k views

Reprojected MODIS NDVI has range from -32768 to 32767, expected -1 to 1

I'm new to StackExchange and to remote sensing. I am working with MOD13Q1 250m 16-day MVCs. My goal is to use NDVI time-series to classify cropping pattern and crop type, then link this data to ...
1
vote
1answer
927 views

How to get “p value” for time series data to detect significant change

I have yearly maximum NDVI data (1982-2008) and extracted all value to Excel. Also calculated slope value for each point during the 27 years. All of you know the slope value represents changes per ...
1
vote
2answers
3k views

Extract pixels from NDVI in ArcMap

I have a NDVI that I created from a Landsat 5 image. Is there a way to extract all the pixels above a certain threshold and save it as a shapefile? I am trying to create a vegetation mask of sorts to ...
2
votes
1answer
442 views

Using ASTER for time series analysis?

This is a follow up to Where to obtain free 15m ASTER image for New Mexico?. If I want to analyze 10 years or so, do I need to download each ASTER file for each year (e.g. 2003 ASTER, 2004 ASTER,...)...
2
votes
3answers
1k views

Where to obtain free 15m ASTER image for New Mexico?

I am looking for a free Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image that will let me to perform NDVI for the pilot crop health/soil moisture that can go as far back ...
1
vote
0answers
306 views

Change Detection ArcGIS with multiple dates

I'll explain my aim first: I am trying to create a single raster to represent vegetation resilience, I am doing this via change detection. So far I have created 5 Change detection images, where 2000 ...
4
votes
3answers
2k views

How to efficiently export specific files from .hdf to .img

I am working with MODIS .hdf grid files and am looking for some help on exporting specific files from the .hdf. There are 200+ .hdf's and I need to extract the 0, 1, 2, and 11 (NDVI, EVI, quality, and ...
2
votes
0answers
2k views

Interpreting NDVI value on water?

There is a surreal thing on my NDVI images. NDVI values on lake is ranging from -0.04 to 0.7. (The lake surrounded by forest and has freshwater). Theoretically, negative value of NDVI is correspond to ...
4
votes
1answer
911 views

Creating management zones in NDVI ortho maps with contour like lines

This question is hard to explain so if you have a possible answer I would love to hear it. I work in the precision agriculture business which heavily relies on NDVI calculations but need to create ...
2
votes
2answers
2k views

NoData Value = 0, problem when creating NDVI, Erdas

I try to create an NDVI from Landsat and ASTER satellite images using Erdas Imagine. In Erdas, the satellite images have a nodata value of 0. After creating an NDVI, the nodata value is still 0, but ...
2
votes
1answer
436 views

Right raster zonal statistics for NDVI at county scale?

I am currently doing a modeling project at county scale in which I have disease rate as dependent variable and environment variables (such as temperature, NDVI and evapo-transpiration) as the ...
3
votes
2answers
631 views

SPOT NDVI time series

I have 423 spot.vgt ndvi from first April 1998 till 31 Dec 2009. I want to know how to stack these NDVI to have one image for time series analysis? Or better to ask how is it possible to analyze a ...
1
vote
0answers
131 views

Spot NDVI spatial reference system

I have a series of spot NDVI data for Australia and I need to extract some information from it. Unfortunately there is no spatial reference system attached to it. This is one example of the data (HDF ...
3
votes
2answers
12k views

Creating NDVI from multispectral imagery?

I have LISS IV image data in three bands (band4, band3 and band2). I wanted to know the required steps to obtain the NDVI image from the given data using ERDAS IMAGINE 9.2.
16
votes
4answers
2k views

Alternative vegetation indices

I have been using NDVIs with limited success to identify trees in the central Great Plains region of the USA. The problem I have been encountering is that reflectance from farm fields/pastures have ...
1
vote
1answer
2k views

Removing pixel values below -1 using ENVI?

I have downloaded NDVI from MODIS website and pixel values go up to -3000 to 1. I want to remove all values below -1. How do I do this? I am using ENVI 4.3
3
votes
3answers
2k views

NDVI image value changes from -1 to 1 in ENVI to 0-255 in ArcGIS Desktop and ERDAS Imagine?

When i open NDVI image in ENVI, its value is still within the range (-1 to 1). But when I open this NDVI image in ERDAS and ArcGIS Desktop, its value is 0-255. What does it mean? Is the NDVI ...
7
votes
2answers
9k views

Performing regression analysis between two variables using ArcGIS Desktop?

I have a temperature image (interpolated from climatic point data) and NDVI data at the monthly interval. I need to do correlation analysis between temp and NDVI. Is it impossible to do this using ...
3
votes
1answer
430 views

Determining phenological events based on Greatest increase NDVI approach?

I have a problem with a phenological study. The study area is in temperate zone of Asia. I have been doing phenological research using MOD VI product. I wanted to extract phenological events (onset/...
4
votes
3answers
6k views

How to create animation from raster data?

I have some NDVI and precipitation/temperature images at the monthly time step from Jan, 2005 to Dec, 2008. I need to create animation image to show the temporal change. How can I do this? Is it ...