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1 Replies and 982 Views Tasseled Cap Landsat 7  982  1 Started by  Deleted User Hello everybody, I actually have a similar problem. I have Landsat ETM images that should be transformed via tasseled cap. Besides I already calculated the surface reflectance. Now I have three possibilities: &160; 1) Applying the Landsat 7 at-satellite reflectance coefficients in combination with the surface reflectance data &160;&160; IS THAT VALID 2) Calculate the at- satellite reflectance and then use the Landsat 7 coefficients 3) Use the surface reflectance values in combination ...
1 982
14 Apr 2010 11:12 AM
1 Replies and 894 Views Adding function to spectral plot window  894  1 Started by  Deleted User I would like to add a function to the ENVI spectral plot window in a manner in which the currently displayed spectrum is sent to be processed by the function (when selected by the user from the "Plot Function" drop-down list).&160; I added the following the the "useradd.txt" file: {plot} {MICA Analysis} {interactive_mica_from_plot} {type=0} It works fine for a single spectrum, but when I move to a new location in the image window, the function begins to execute again with ...
1 894
08 Apr 2010 12:54 PM
1 Replies and 1177 Views NDVI Error  1177  1 Started by  Deleted User Dear Forum, I have a problem in calculating NDVI in ENVI (4.5). I have downloaded Landsat 5 TM data from USGS site and am trying to compute NDVI using tranformation option. Firstly, I have converted, my DN value to TOA reflectance values for all the bands. The problem is , when I compute stats for band3 (Red) and Band4(NIR) separately, it gives me min and max value ranging from -0.001 to 0.36 for band 3 and -0.001 to 0.39 for band 4. That is Ok. Now when I calculate NDVI from these two bands,...
1 1177
07 Apr 2010 10:22 PM
2 Replies and 1596 Views Landsat 7 import problem  1596  2 Started by  Deleted User I'm a student new to ENVI so I apologize if this is a stupid question but I have some landsat 7 ETM data that opens in ENVI all as a band 1. Is there a way to manually change the band or does ENVI no support this data I'm using ENVI 4.6. Thanks
2 1596
07 Apr 2010 05:20 AM
5 Replies and 3324 Views Image stacking problem  3324  5 Started by  Deleted User Greetings, &160; I am trying to create an image stack in chronological order from the command line as the GUI interface seems to want to read my files in&160; from last to first and not vice-versa.&160; To add insult to injury I have 232 files to read just for this one stack&160; so I cannot be bothered with trying to manually reorder them in the GUI.&160; I decided to write an IDL function to do this, which successfully reads the imagery into ENVI and records FIDs and dims into separate ...
5 3324
06 Apr 2010 02:30 PM
2 Replies and 1144 Views atmospheric correcting hyperspectral data  1144  2 Started by  Deleted User In atmospherically correcting the AVIRIS image using FLAASH in ENVI tutorial, comparing the first input file(JsperRidge98av.img) with the corrected image(JapserRidge98av_flassh_relf.img), what is the difference between input radiance and final resulting reflectance Do they have same unit And how can I calculate them Tell me about the way with using scale factor. Next, I want to compare the reflectance of corrected image with spectral library numerically. In that case, which spectral library i...
2 1144
01 Apr 2010 03:25 PM
1 Replies and 4008 Views Importing to ENVI from Google Earth  4008  1 Started by  Deleted User I have not found a way to import KML or KMZ files into ENVI. Does anyone know if this is possible
1 4008
01 Apr 2010 08:59 AM
3 Replies and 1594 Views Problem in Importing Hyperion L1R data  1594  3 Started by  Deleted User I am trying to import Hyperion L1R data using Hyperion Tools. I am getting the following error: "HDF_SD_SELECT: Unable to select the HDF-SD dataset (SDINTERFACE_ID)." What does this error mean and what is the solution for this error
3 1594
31 Mar 2010 06:43 AM
1 Replies and 2161 Views ROI Separability - Jeffries Matusita  2161  1 Started by  Deleted User Hello I want to calculate the Jeffries- Matusita separability &160;in ENVI, but I have several ROIs in separated files (not only one). How can I calculate de J-M distance I can not perform a mosaic with all the images in order do have a unique ROI file because it is a huge file (images spread all over the country). Does anybody know how to do it in ENVI or with a function in IDL, or in Matlab Thank you
1 2161
26 Mar 2010 02:56 AM
1 Replies and 1198 Views resampling of spectral bands  1198  1 Started by  Deleted User Hello group, I am trying to discriminate a material using its spectra. I have collected the spectra in the field using a spectroradiometer with 16 bands. But I am having some probelms correlating these to a MSS &160;image with 4 bands before doing a Spectral Angle Mapper classification on the image. It gives me an error message that the bands are not compartible. So how can I resample the spectral bands of the data from the spectroradiometer from 16 bands to 4 bands, as to make my classificati...
1 1198
24 Mar 2010 12:30 PM
2 Replies and 1660 Views Radiometric normalization  1660  2 Started by  Deleted User Hello. I would like to know if there is a tool for performing radiometric normalization in ENVI (4.6). I've been trying with the SPEAR Change Detection wizard but I'm not sure if that's the right way to do it because I don't get to chose PIFs. Is there another way to do the normalization I'm working with Landsat ETM (SLC on) images. Thanks Sophia
2 1660
24 Mar 2010 09:47 AM
3 Replies and 1445 Views Neural net  1445  3 Started by  Deleted User Hi all, Could any one of you&160;provide some tips on how to use neural net&160; (within ENVI 4.5) for soil mapping.&160; I failed to open the raster file in ENVI&160; (&160;vector file converted to Raster in ArcGIS 9.2). Is there any way forward Thank you in advance
3 1445
24 Mar 2010 01:55 AM
1 Replies and 1072 Views Automated GCP -> polynomial coefficients?  1072  1 Started by  Deleted User Hi.&160; I have a collection of GCP .pts files from previously done image to image registration, probably about 50, and I would like to independently extrapolate the transformation polynomial coefficients from each .pts file.&160; The only way I've found to do this is to load two image files, then restore the GCP points from file, then re-save the coefficients to file.&160; Is there a way to automate this process without the unecessary steps of opening two image files&160; Once the GCPs are...
1 1072
22 Mar 2010 01:36 PM
9 Replies and 1811 Views Tasseled Cap Transformation - Input Bands?  1811  9 Started by  Deleted User Hi, I'm hoping to run a tasseled cap transformation on Landsat-5 TM data, and have two questions: 1. What input bands does ENVI take I'm assuming bands 1-5, and 7, in that order 2. Does ENVI expect uncorrected raw DN values, or reflectance data Thanks! &160; &160;
9 1811
21 Mar 2010 02:39 PM
1 Replies and 1314 Views Earthquake & georreferencing  1314  1 Started by  Deleted User Has anything been affected in geometric correction (specially in georreferencing) with the earth & axis movement Thanks!
1 1314
16 Mar 2010 05:52 PM
1 Replies and 1266 Views Spectral information Divergence (SID)  1266  1 Started by  Deleted User Hello all, Does anybody knows what log stands&160;in calculation for spectral information divergence (SID), i mean whether loge, log10 or log2. I think, it should be log2&160;, then the SID output&160;might result&160;potentially&160;0 to infinity. How&160;the result is scaled to 0 to 1&160; Sukuchha&160; &160;
1 1266
16 Mar 2010 11:40 AM
4 Replies and 1859 Views Envi and Matlab  1859  4 Started by  Deleted User Hi, I'm a newbe of Envi. I have to export a ROI complete dataset of Meris L2 images in Matlab. I have create the ROI after georeferencing many images, I applayed the Roi to all images, and it works. I have the same ROI on all images. Now I have to export the ROI data of each band (and mask) to a format Matlab-compatible. Can someone help me Thanks &160;
4 1859
11 Mar 2010 09:34 AM
9 Replies and 1593 Views Use of TIFF files  1593  9 Started by  Deleted User Hello, I want to use TIFF files with ENVI. They have a correction level called "L1T Standard Terrain Correction", and are provided by the USGS. It is said in the guidelines of the USGS place, that this correction level provides systematic and radiometric accuracy by incorporating ground control points. I need to classify the images and my question is, I need to correct them radiometric and geometrically before starting or all of this corrections are already applied when you open the ...
9 1593
10 Mar 2010 11:13 AM
1 Replies and 1351 Views ENVI issues with TIFF files  1351  1 Started by  Deleted User Hi all, I have been using ENVI for some time, but recently I've encountered issues with TIFF files. When I try to load one in ENVI there is a very long pause before it appears in the 'Available Files List'. For a small file (1000x550 pix floating point, 2.2MB) there is a delay of approximately 5 minutes, during which time ENVI is unusable. I have tried loading files from local disks, external disks, network drives, the problem persists on all of these. No new software has been installed, and t...
1 1351
09 Mar 2010 03:00 AM
1 Replies and 1384 Views Convert Airborne Digital Images DN to reflectance values  1384  1 Started by  Deleted User Hello I&180;m a new user of ENVI. I&180;m start to working with airborne digital images (50cm spatial resolution, 4 bands- blue, green, red and infra red (TIFF format). I want to convert the DN to reflectance values. The Preprocessing Tool in ENVI as a standard Calibration Utilities for several current images, namely Landsat, QuickBird, etc. But how can I convert DN to reflectance values using airborne images Can someone help me Thank you Ros&225;rio
1 1384
08 Mar 2010 09:07 AM
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Page 91 of 137 << < 8990919293 > >>