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1 Replies and 1429 Views
Best method for vegetation analysis 1429 1
Started by Deleted User
I'm probably asking a question that requires a research project, but has anyone found a method to extract species of plants using a spectral library
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1429 |
27 Apr 2015 02:58 PM |
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3 Replies and 1612 Views
decorrelation stretch, is there a reference? 1612 3
Started by Deleted User
I could not find any clear explanation on what ENVI does during the decorrelation stretch. There is only the following information online:
Tip: You can obtain similar results to decorrelation by using a sequence of forward principal components (PC), contrast stretching, and inverse PC transforms.
Is there any reference describing the actual implementation
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1612 |
24 Apr 2015 07:52 AM |
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1 Replies and 1598 Views
calculate co-relation 1598 1
Started by Deleted User
how to calculate co-relation in envi.
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1598 |
24 Apr 2015 04:16 AM |
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1 |
1259 |
21 Apr 2015 04:29 PM |
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2 Replies and 1628 Views
SAM/MF classification 1628 2
Started by Deleted User
Can Spectral Angle Mapper or Matched Filtering classification be performed without doing Pixel Purity Index If not why If yes how
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1628 |
20 Apr 2015 02:34 AM |
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1 Replies and 1303 Views
layerstacking 1303 1
Started by Deleted User
I am trying to layerstack several landsat 8 bands (all of which are mosaicked landsat bands). Each band is projected the same (UTM WGS84 21N) and I choose the layerstck parameters to match. However, the result repeatedly comes out to be zone 21S. I am trying to preserve data values, so reprojecting back into zone 21N is not a good option. I cannot determine why it would be changing, nor why choosing the correct zone will not assure the result will be projected accurately.
I have tried ENVI and t...
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1303 |
17 Apr 2015 09:17 PM |
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1 Replies and 1488 Views
How to edit class names and colors 1488 1
Started by MariM
After I create a classification image through the'Classification Workflow', the default simply names the classes as Class 1,Class 2, etc., and assigns them default colors. I need to change the names and colors of these classes, so I right-click on the classified image in the "Layer Manager" and click on 'Statistics for all classes...' It brings up the 'Classification Statistics View' dialog box, in the 'Curve' tab. I can change the name and color, but it has no effect on changing the ...
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1488 |
17 Apr 2015 01:38 PM |
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3 Replies and 1635 Views
Mosaic Landsat 8 1635 3
Started by Deleted User
I would like to mosaic two surface reflectance scenes, but preserve the reflectance values in the mosaic. I have use the seamless mosaic tool with settings I thought would accomplish this, but each time the resulting reflectance values are far too low.
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1635 |
17 Apr 2015 08:02 AM |
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1 Replies and 1332 Views
help getting decision tree expression right 1332 1
Started by Deleted User
In ENVI 5.2, I am trying to run a decision tree on NDVI image derived from Landsat 8 satellite data, but I am not getting proper results.
I want to classify the NDVI values which are greater than(>)0.3 as crop lands and lesser then(< )0.3 as non-crop lands.
I tried with the expression. {ndvi} GE 0.3
But its giving result as non agri(ppt attached). Please guide me how to write a correct expression.
I will look forward for your reply.
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1332 |
16 Apr 2015 08:36 AM |
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1 Replies and 1529 Views
hyperion data correction 1529 1
Started by Deleted User
how to correction flag mask and smile affect 'frown' curve.
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1529 |
15 Apr 2015 02:29 AM |
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1 Replies and 1619 Views
IMAGE NOISE & DIMENSIONALITY 1619 1
Started by Deleted User
How I estimate image noise of a Hyperion L1R data. I wants to know about Signal to Noise ratio. please help me.
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1619 |
15 Apr 2015 02:10 AM |
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15 Replies and 1871 Views
NDVI per altitudinal range 1871 15
Started by Deleted User
Good Morning,
I have 5 landsat images (different dates) and a SRTM DEM of my study area. For each image I would like to calculate the mean NDVI per altitudinal range. The altitudinal ranges are the following : 0-3000 m; 3000 - 4000m; 4000-5000m and over 5000m. Should I create different masks per altitudinal range using my SRTM DEM and then clip each images and then run the NDVIs What would be the best method and tools with ENVI My images are already geometrically and atmospherically corrected....
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1871 |
14 Apr 2015 11:42 AM |
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1 Replies and 1765 Views
AUX files ? 1765 1
Started by Deleted User
Why doens't ENVI 5.1 produced .aux files when I save the imagery to ERDAS native files so ArcGIS or ERDAS can read it
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1765 |
14 Apr 2015 08:02 AM |
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1 Replies and 1483 Views
Linear Spectral Unmixing with Aster VNIR 1483 1
Started by Deleted User
Hello ! I am having troubles with understanding the results of my unconstrained Linear Spectral Unmixing application in ENVI. The pixels in my resulting fraction images gives me data that ranges from -3 to 9. Can I still use this data even though they are very much outside the 0 to 1 range What can I do to improve my unmixing Also, is it normal that a single value (0.15....) was attributed to all of the background that I had defined with a mask
Here is some more detailed information : I ...
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1483 |
09 Apr 2015 01:16 PM |
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7 Replies and 1381 Views
TIF to 1381 7
Started by Deleted User
So, whenever I stacked the bands and save them in TIF file..it looks like ERDAS 2013 I have on my computer does not like to open it.
Is there a way around to fix it or is it that I need to upgrade to ERDAS 2014 they are having a problem with the ERDAS 2013
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1381 |
08 Apr 2015 08:55 AM |
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1649 |
08 Apr 2015 04:19 AM |
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2 Replies and 1577 Views
Remove a band from an imagery 1577 2
Started by Deleted User
What tool do you use when you remove a band from a multispectial, for example,, when you stack a few bands and realized you don't need a band....
Thanks,
Robert
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1577 |
07 Apr 2015 12:37 PM |
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2 Replies and 1506 Views
Metadata Viewer Question 1506 2
Started by Deleted User
Hello all,
Currently I am using ENVI 5.1 I upgrade from 5.0 a few months ago back..now I am starting to work on ENVI again,.. Now I have a question how to export the spectral attribute of the wavelength when you open text in ENVI. It shows all the spectral information in the Metadata Viewer. The Metadata Viewer has the button "export"l that you can save it.
I would like to hear your input on that if there a way around for me to add it when I stacked the bands
Adios !
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1506 |
02 Apr 2015 05:11 PM |
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1 Replies and 1662 Views
Spectral Angle Mapper for multiple classes 1662 1
Started by Deleted User
What does spectral angle mapper do when a test spectra matches more than one reference spectra Does SAM give priority to one reference spectra over an other based on how the library is built i.e. if the test spectra matches two reference spectra, and one is listed first in the library, does SAM give priority to the reference spectra listed first How would SAM resolve if a test spectra falls within the angle cut-off of two reference spectra
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1662 |
01 Apr 2015 10:15 AM |
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1 Replies and 1938 Views
extinction coefficient and visibility 1938 1
Started by Deleted User
Where does the equation relating the extinction coefficient to visibility shown in the FLAASH tutorial at https://www.exelisvis.com/portals/0/pdfs/envi/Flaash_Module.pdf come from I am referring to the equation:
V=3.912/ ß
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1938 |
30 Mar 2015 12:55 PM |