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1 Replies and 1266 Views
registration of thematic map to geographic coordinates of longitude and lattitude 1266 1
Started by Deleted User
i have a thematic map that has been digitized into tif format. I am attempting to reister the map to geographic units of longitude and lattiude. To do this in ENVI i use the map ---> registration ----->select GCP's image to map. I set the registration projection to geographic lat/lon. The location of the GCPs i am using is the intersect of latitude and longitude values i.e. my map is of Guyana so one of the points i use is -2 lat and 61 long (degrees). However when i plot 3 or more gcps the pred...
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1266 |
27 Jan 2011 06:17 AM |
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2 Replies and 1033 Views
ENVI ArcGIS Tools - feature extraction 1033 2
Started by Deleted User
Hello,
I'm trying to extract features from a QB image and I'm wondering how I could use an existing ruleset XML file to get the tool to work. Does the XML ruleset have to be created in ENVI EX 4.8 If so, does it need to come from the same image used in the EX workflow I'd like to use a kind of 'template xml ruleset' that I could ideally apply to other QB images.
When I look at the XML file that I saved from the ruleset feature extraction tutorial created in ENVI EX, it seems to contain...
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2 |
1033 |
25 Jan 2011 10:00 AM |
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2 Replies and 1107 Views
Problems in importing .jp2 images 1107 2
Started by Deleted User
Hello,
We need to import compressed .jp2 images into ENVI. These images come as two files. The one files is the actual image (.jp2) and the other (.j2w) describes the "begining" of the image in terms of coordinates. However, in the available bands list the Map information icon won't appear, and during import there is no "question" about the coordinate system.
Any hints and ideas, about what it can be done to set the spatial reference of the images
Thanks,
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2 |
1107 |
25 Jan 2011 06:57 AM |
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1 |
2171 |
24 Jan 2011 05:16 PM |
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3 Replies and 1300 Views
problemas con el SVM 1300 3
Started by Deleted User
Hola!
estoy comenzando a trabajar con ENVI. En estos momentos estoy intentando realizar una clasificacion supervisada con SVM en un mosaico constituido por 4 imagenes y 10 clases.
Sin embargo, luego de dejar que el programa corra durante toda una noche ocurren differentes errores (y he utilizado maquinas con distintas capacidades). Alguien ha tenido este problema sabe como resolverlo
Muchisimas gracias!
L.
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3 |
1300 |
24 Jan 2011 11:13 AM |
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1 Replies and 1131 Views
orthorectification 1131 1
Started by Deleted User
Having used the RPC file to perform an orthorectification of a QuickBird image, I need to know how do you check the accuracy (RMSE) of the rectification
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1 |
1131 |
24 Jan 2011 05:37 AM |
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1 Replies and 1149 Views
Georeferenced MODIS 1149 1
Started by Deleted User
I was trying to georeferenced my MODIS Products but an error came out that says, "MODIS is already geoferenced". What do I do after this
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1 |
1149 |
20 Jan 2011 08:28 PM |
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1 Replies and 1072 Views
PCA 1072 1
Started by Deleted User
Hallo,
when I use teh PCA, is there any way to get the wavelength information for the first 10 or 20 significant PCA-Bands.
I must know which wavelengths will be (most) use for this PCA bands.
Thanks in advance Joachim
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1072 |
20 Jan 2011 01:26 AM |
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1 Replies and 985 Views
Georefencing MODIS using Multiple Topographic Maps 985 1
Started by Deleted User
Georefencing MODIS using Multiple Topographic Maps
Is this possible using ENVI 4.3 Using the Registration Toolbar, I can only open one topographic map at a time. But the Satellite Image (MODIS) covers large areas that it extends to several topographic maps. If I were to register the satellite image per topographic it will really take me time. I have 50 topographic maps and 300 satellite images to georeference. Please advise. Thank you.
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1 |
985 |
19 Jan 2011 08:41 AM |
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0 Replies and 1087 Views
Georefencing MODIS using Multiple Topographic Maps 1087 0
Started by Deleted User
Georefencing MODIS using Multiple Topographic Maps
Is this possible using ENVI 4.3 Using the Registration Toolbar, I can only open one topographic map at a time. But the Satellite Image (MODIS) covers large areas that it extends to several topographic maps. If I were to register the satellite image per topographic it will really take me time. I have 50 topographic maps and 300 satellite images to georeference. Please advise. Thank you.
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1087 |
19 Jan 2011 08:40 AM |
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3 Replies and 1276 Views
GRACE and TRMM data 1276 3
Started by Deleted User
Hello
Can someone tell if ENVI support the import and analysys of GRACE and TRMM data - used for measuring the Earth gravity field and rainfall respectively Where can I read about it and are there any case studies avaliable
Thanks,
Eva
www.emaps.dk
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3 |
1276 |
17 Jan 2011 01:42 PM |
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1 Replies and 1204 Views
bewilderment about worldview-2 atomoshperic correction 1204 1
Started by Deleted User
i made atomoshperic correction of WorldView-2 by flaash in Envi4.7. But band1 and band2 of worldview-2 almost were negative value after correction.
In addition, i found correlations between radiance and field data were higher than reflectance. Why someone could give me some suggestion about these two puzzles Thanks lot.
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1 |
1204 |
16 Jan 2011 06:05 PM |
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1 Replies and 1242 Views
Output file (Rigorous Orthorectification ) 1242 1
Started by Deleted User
The output file from module of orthorectification rigorous is truncated when viewed, in the preview is complete but the end result not, what could be happening
Thanks
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1 |
1242 |
16 Jan 2011 03:58 PM |
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2 Replies and 1166 Views
Correcting brightness gradient across CIR image. 1166 2
Started by Deleted User
I'm new here, and had a question about how to adjust images that clearly have a brightness gradient from one side to the other side - due to sun angle or sensor angle etc.. These are old 1985 CIR images, and I have several that show the same effect. What's the best way to make corrections on these I am imagining something involving averaging values across each column of pixels, on all the images with this effect, and subtracting that value If so, how is that done on ENVI
thank you!
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2 |
1166 |
14 Jan 2011 08:52 AM |
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1 Replies and 1101 Views
Problem converting LiDAR LAS file to ENVI raster 1101 1
Started by Deleted User
I am trying to extract the first and second returns from a LAS file in ENVI 4.8 - by conerting it to an ENVI Raster File
I use the following flow: Open External File --> LAS LiDAR --> Convert LAS Data.
This procecure produces the intended raster file (DEM), but there is no geographic cordinate information when I use the Cursur Location/Value tool in the image window - only the row and column values.
There are no Select Output Image Projection available. In the help section is sta...
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1101 |
13 Jan 2011 11:23 PM |
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1 Replies and 1105 Views
Subsetting an Image: Max and Min Threshold Value 1105 1
Started by Deleted User
Good day!
I am trying to subset an image from 400x400 to 25x25. However, a pop-up window is asking for the Min threshold value, max threshold value, population, and number of neighbors. What values do I input and how do I determine these values Thanks.
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1 |
1105 |
13 Jan 2011 10:22 PM |
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1 Replies and 997 Views
feature extraction with 5 bands (ENVI EX) 997 1
Started by Deleted User
My feature extraction on a 5 band image fails. Same image with 4 bands works fine. Symptom is that the layers section only shows band 1 in grayscale, although the data manager shows all 5 bands. Scaling produces one (big black) segment. The first clue that it won't work is that the preview pane reveals nothing, even after several minutes of calculating statistics.
I will try the 5th band as a mask instead, although I read that might not work either. Would appreciate any words of wisdo...
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997 |
12 Jan 2011 03:14 PM |
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2 |
1230 |
12 Jan 2011 11:54 AM |
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4 Replies and 4537 Views
How to get the minimun/maximum NDVI value (NDVI_soil/NDVI_vegetation)? 4537 4
Started by Deleted User
I want to get the fraction of vegetation cover(FVC).
The calculation equation is f=(NDVI-NDVI MIN)/(NDVI MAX-NDVI MIN).
The NDV_MIN value is likely to be the value of soil. And the NDV_MAX value is the value of full vegetation cover.
How to calculate the NDV_MIN value and the NDV_MAX value
Are there any other methods to calculate the fraction of vegetation cover
Best regards
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4 |
4537 |
10 Jan 2011 06:17 AM |
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11 Replies and 1624 Views
worldview2 atmospheric corrections 1624 11
Started by Deleted User
hi there!
im using version 4.5 of envi and apparently does not cater to wv2 functions (e.g. preprocessing). im trying to apply atmospheric corrections but im a having hard time comprehending it. also, i would really appreciate if anyone could share or give me an idea how to produce a spectral response function (SRF) of a WV2 sensor type.
please advise. tnx!
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11 |
1624 |
09 Jan 2011 02:52 AM |