Questions tagged [envi]
A remote sensing and image analysis software package produced by Exelis Visual Information Solutions (Exelis VIS).
29
questions
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1
answer
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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 ...
- 759
9
votes
2
answers
4k
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Landsat8 DN to TOA Reflectance (minus values)
I'm learning how to perform atmospheric correction manually, hence not using the automated methods available in ENVI
metadata (band 1) for my Landsat 8 scene is as follows;
RADIANCE_MULT_BAND_1 = 1....
- 93
9
votes
2
answers
16k
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How to repair topology of a shapefile?
I performed an object-based image analysis using ENVI EX, and each of the classified features were exported as a shapefile. I transferred those shapefiles into ArcMap 10, and tried to intersect them ...
- 981
6
votes
5
answers
9k
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Fixing Landsat 7 SLC-off in ENVI
I have a couple of Landsat 7 images and they all have striping as a result of the SLC failure. Does anyone have any suggestions as to how to destripe the image using ENVI? I plan to use these images ...
- 165
5
votes
2
answers
12k
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Replacing Raster Values in Ras1 with Ras2
I have two rasters Ras1 and Ras2.
I want to change the Ras1.
In Ras1, there are few areas, lines, points I am interested having nodata cells and wrong data cells.(limited to interested areas only ...
- 814
4
votes
2
answers
7k
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Converting *.tif file into headerless (flat) binary file?
I am using NDVI files (value range -1 to +1) created from Landsat CDR images to produce a timeseries in TIMESAT software.
My .tif file has following characteristics.
File type TIFF,Data Type ...
- 61
3
votes
1
answer
2k
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MOD 35 Cloud Mask HDF in ENVI
I am having difficulty getting ERDAS or ENVI to correctly read and display cloud mask attributes from MOD 35 HDF files. They files are displayed as 0-255, whereas I expected some kind of code 0, 1, ...
- 81
3
votes
1
answer
8k
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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 ...
- 63
0
votes
1
answer
1k
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GeoTIFF created using ArcGIS for Desktop not displaying in Google Earth or Photoshop?
I originally had an IMAGINE Land Cover raster file that I opened in ArcMap.
I used the Extract Feature from Raster to extract only the Developed class and saved it (still IMAGINE).
Then I used the ...
- 165
0
votes
2
answers
6k
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.tif and .tfw to GeoTIFF [duplicate]
I have a .tiff and a .tfw file that I want to change into a GeoTIFF. When I try to open the file in ArcMap and ENVI 5.0, it is successful. However, in Google Earth it is not.
Is there anyway to ...
- 165
0
votes
1
answer
3k
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Imagine files between ERDAS and ENVI
I have ENVI 5.0 , ERDAS 2013 SP2, and ArcGIS 10.1 SP1. Every time I save an Imagine file from ENVI 5.0 and open in ERDAS 2013 and it seems like ERDAS does not like it and it would not open and would ...
- 4,131
8
votes
1
answer
2k
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Rotate ENVI hyperspectral imagery with GDAL
I am developing an application with the GDAL library to combine georeferenced raster hyperspectral imagery in ENVI format from NASA's Airborne Visual/Infrared Imaging Spectrometer (AVIRIS) with other ...
6
votes
4
answers
482
views
Transform raster donuts to circles
Let's assume I have a raster image consisting of 0's and several donut-shaped rings of 1's. This raster could for example be the result of classifying a satellite image with ponds and lakes in it into ...
- 1,035
5
votes
1
answer
334
views
Classifying different surfaces having almost similar Reflectance responses
I am using ENVI 5.3 to classify a Region of Interest clipped from Landsat 8 OLI. I have already performed calibration of my DNs by transforming it into Radiance and derived Reflectance image using ...
- 1,198
5
votes
1
answer
636
views
Identifying pixels with sun glint in a satellite image (for atmospheric correction)
Wondering if anyone knows a way (perhaps objective) to identify pixels that are infected with sun glint in an image. I'm using Hedley's 2005 approach in a python to deglint my image but this approach ...
- 507
4
votes
1
answer
383
views
Differences in the longitude and latitude between a LiDAR DSM and an optical image
I've downloaded the UK's LiDAR elevation data (see below) in laz format for a specific region (Tewkesbury) from: http://environment.data.gov.uk/ds/survey#/download
From that, a DSM (Digital Surface ...
- 956
4
votes
3
answers
3k
views
Matching colours in already mosaiced single image? [closed]
I have an already mosaiced image for a large area. I need to match colours in this single image. I do not have each image separately. I just have this large single image downloaded from GLS. How can I ...
- 91
4
votes
1
answer
646
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 ...
- 1,198
3
votes
1
answer
901
views
How to extract impervious areas from Landsat data?
I'm working with multi-temporal datasets from Landsat (Landsat 8 & Landsat 7 & Landsat 5) and I tried to extract impervious areas, more exactly urban areas, but I can't obtained results very ...
- 31
3
votes
5
answers
4k
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Batch process to get single band image from stacked image using ArcGIS, ERDAS or ENVI?
Can you help me to extract a single band image from stacked multiband image. Totally, 260 image has been stacked. When I do to this, it will take a long time. So I'd like to know there is any batch ...
- 169
3
votes
3
answers
2k
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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 ...
- 31
2
votes
5
answers
8k
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Creating a Time series NDVI map [closed]
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 ...
- 4,131
2
votes
2
answers
653
views
Extracting coastline as vector from landsat 8 imagery?
I am trying to detect some sea level rise/fall for a specific region, from Landsat imagery.
I went through the recommended methods of identifying water/land (MNDWI, AWEI, Bandratio 5/2, etc.).
Now ...
- 205
1
vote
2
answers
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 ...
- 165
1
vote
1
answer
346
views
How can I choose values from stacked raster images according to location of ROI
Before I choosed ROI on land surface temperature (LST) images and obtained pixel values of LST. Now I need pixel value of another images which are stacked multi-band image. My main purpose is to ...
- 659
1
vote
1
answer
4k
views
Loading ENVI file into ArcGIS Desktop?
I received a series of *.img files with a single .hdr file that contains the necessary georeferencing information (i.e., samples, lines, coord system, etc.). I presume this is an ENVI header file ...
- 21
0
votes
3
answers
11k
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how i calculate land surface temperature using landsat 8 in Envi 5.1
I am doing research about land surface temperature using Landsat 8 image. However, I have a problem with them. I have read document from Landsat.org, but i can not do it in Envi. Could you help me ...
- 11
0
votes
2
answers
6k
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Removing black background in ENVI
I am trying to compare two DEM products ASTER and SRTM v.3, but the ASTER has the black background which i think will interfere with my analysis. I don't have access to ArcGIS where I can do this ...
- 25
0
votes
0
answers
157
views
Difference between two atmospherically corrected Images
I corrected Landsat 5 image with two different methods, first atmospheric correction through calibration (means converting raw image into radiance), second atmospheric correction through QUAC ...
- 151