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2 Replies and 1755 Views
Preview Problem in Feature Extraction 1755 2
Started by Deleted User
In feature extraction workflow, 'preview' option is not working right during segmentation step. The preview screen is completely black and green segments are not visible. I can extract details when I do the same operations using the tutorial data used in the tutorial videos of Envi but preview is inactive. Do you know how to solve this problem or have you ever encountered this problem before
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by MariM 05 Feb 2018 08:20 AM |
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20 Replies and 10160 Views
Radiometric correction- WorldView 3 images 10160 20
Started by Deleted User
Hi, I have a WorldView 3 image (Standard 2A product, 8 bands) and I am trying to do radiometric correction with ENVI 5.4.1. The image do not have the gain and offset values and Digital Globe said they do not give these data along with the image. Therefore, I can not do the regular radiometric correction for this image. Can anyone help me with this problem Thank you in advance! Prabha
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by Deleted User24 Jan 2018 09:12 AM |
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24 Replies and 6224 Views
WorldView-3 - FLAASH 6224 24
Started by Deleted User
Hi, I'm trying to use the FLAASH module to perform radiometric correction to my data. But I face several problems.: - I can't load .IMD or .TIL file to provide scale factors informations (absCalFactor = xxx ; effectiveBandwidth = xxx;) to FLAASH module, - I have a warning message concerning the azimuth and zenith angles (Zenith angle is greater than calculated horizon angle.). Thanks,
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by Deleted User22 Jan 2018 12:40 PM |
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5 Replies and 4786 Views
ASTER - FLAASH 4786 5
Started by Deleted User
Hello, I tried an atmospherical correction with FLAASH on ASTER L1T data (The ASTER Level 1 Precision Terrain Corrected Registered At-Sensor Radiance (AST_L1T) data contains calibrated at-sensor radiance, which corresponds with the ASTER Level 1B (AST_L1B), that has been geometrically corrected, and rotated to a north-up UTM projection), but my values are really odd. I have strong positive and negative values ( 32 010 to -32 752). I tried to follow step by step the tutorial here: http://...
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by MariM22 Jan 2018 06:14 AM |
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5 Replies and 4801 Views
WorldView 2 Radiometric Calibration 4801 5
Started by Deleted User
Hello, I am running ENVI 5.3 and I would like to derive TOA Radiance from WorldView 2 Imagery using the Radiometric Calibration Tool. Digital Globe recommends to use the following equation: L = Gain * DN * (abscalfactor/effective bandwidth) Offset I successfully imported .til file, and the associated metadata. The metadata doesn't seem to import the abscalfactor and effective bandwidth from the imd file though. And the Radiometric Calibration Tool seem applying the following equation...
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by MariM18 Jan 2018 12:13 PM |
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7 Replies and 2958 Views
FLAASH TO CORRECTION GEOEYE1 2958 7
Started by Deleted User
Hi, I'm trying to correction the geoey1., but I'm having problems. This error: dialog text: ACC error: convert7 IDL error: End of input record encountered on file unit: 0. ACC_CONVERT7 ACC_HYPER2 ACC_ACC_EVENT ENVI_FLAASH_PROCESS_MANAGER $ My metadata doesn't have a gain and offset, So i need to calculate de radiance for each band, using the expression: (Gain pixel value* offset) using the data of digital globe. Then I stacked the bands and transformed in BIL. The parameters input are:...
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2958 |
by Deleted User22 Dec 2017 09:29 AM |
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5 Replies and 2285 Views
Atmospheric correction on ASTER data 2285 5
Started by Deleted User
Hello, I have an ASTER image (one TIF per band). I would like to perform a FLAASH correction but it seems that i need a BIL or BIP format. I used Basic Tools > Convert Data (BSQ, BIL, BIP), it works but when I use the output file to do the FLAASH tool I have this message: ''Number of rows in this file is inconsistent''. Where did I do a mistake Thanks.
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2285 |
by Deleted User21 Dec 2017 02:06 PM |
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2 Replies and 1579 Views
Calculate a mean spectra 1579 2
Started by Deleted User
Hi, I'd like to map minerals with MTMF, or SAM. I use spectra from the USGS spectral library, but there are several spectrum for each mineral. Is it possible to calculate a mean spectrum from 5-6 spectra of a same mineral Thanks, Ludovic
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1579 |
by Deleted User18 Dec 2017 11:03 AM |
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7 Replies and 2844 Views
Mixture Tuned Matched Filtering 2844 7
Started by Deleted User
Hello, I tried a MTMF method to map alteration minerals (alunite, kaolinite), unfortunately, it doesn't match at all, the results I had with the SAM method or PCA (the pixels with high MF values and low unfeasibility are quite the opposite actually). I probably did something wrong. Here is how I preceeded: I performed a MNF on my image. I used the forward MNF to spectra tool to convert the spectra from usgs library to MNF space (I saved the resulted plot in ASCII). I used the MTMF met...
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by Deleted User15 Dec 2017 10:03 AM |
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2 Replies and 3564 Views
Sentinel 2 cloud mask 3564 2
Started by Deleted User
I am looking for a workflow allowing me to mask the Sentinel 2 RGB-NIR bands using the cloud mask layer provided with the image. I actually use SNAP toolbox but it is high-resource consuming and not optimized. There is a way to read/open/use the cloud mask layer with Envi/IDL and to perform the cloud mask operation on the 10m layers Thank you for any suggestion.
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by Deleted User12 Dec 2017 03:29 PM |
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1 Replies and 1630 Views
alteration 1630 1
Started by Deleted User
Hello How could i find soil alteration in Landsat 8 Please explain it in details. Thanks.
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1630 |
by MariM11 Dec 2017 10:14 AM |
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1 Replies and 2341 Views
Error opening Sentinel 2 dataset 2341 1
Started by Deleted User
I am trying to import some Sentinel 2 images, opening the xml file provided inside the .zip file. This is the ENVI Error message I am recieving: The path to the image data is too long for Windows; try movinf the data to a directory with a shorter name. The full path of the xml is the following: G:\ArTeK\CivitaBagnoregio\Serie storica\S2- 20150823\S2A_OPER_PRD_MSIL1C_PDMC_20161002T150750_R022_V20150823T101016_20150823T101725.SAFE\S2A_OPER_MTD_SAFL1C_PDMC_20161002T150750_R022_V20150823T10101...
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2341 |
by MariM06 Dec 2017 08:05 AM |
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1 Replies and 1907 Views
Anomalies using 'Data Stretch' tool in ENVI 5.4 1907 1
Started by Deleted User
I have a Landsat reflectance raster clip with values ranging from 52-3089. I am intending to stretch the raster rescale it down to 0.0052-0.3089 (floating type) with linear stretch. A close analysis of the histogram of resultant stretched raster with the histogram of original raster highlights anomaly in the results . I know I can get desired results by multiplying the original raster with 0.0001 but I am not sure why there is such discrepancy in the results using Stretch Data tool.
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1907 |
by Deleted User03 Dec 2017 10:34 PM |
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2 Replies and 2046 Views
Resampling IGM bands 2046 2
Started by Deleted User
Hello! I have airborne hyperspectral imagery that I am resampling by pixel aggregation to increase the ground resolution. I also have an IGM file for the original data, to georeference the image after my analysis is completed. I attempted to resample the IGM lat/long bands in the same manner as the data bands, so I could also georeference my resampled image. This was highly unsuccessful. Any tips on how to do this Thank you! Dulci
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by Deleted User27 Nov 2017 11:00 AM |
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4 Replies and 2128 Views
How to get Eigenvectors matrix (with PC in x and bands in y)) 2128 4
Started by Deleted User
Hi, I made a PCA (Principal Component Analysis), I chose to create 8 PC-bands from my 12 image bands (WorldView-3). But when I read the statistic file (Basic Tools > Statistics > Read statistics file...), I have a 12x12 matrix of eigenvectors, is that normal Because I want to get eigenvectors values of my 8 PC-bands for the 12 bands of my image...because I need to choose the right PC-band to map alteration minerals. Thanks.
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2128 |
by Deleted User17 Nov 2017 09:02 AM |
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2 Replies and 2880 Views
Spectral Library Resampling issues 2880 2
Started by Deleted User
Hi, I have a WorldView-3 image and I want to resample the USGS library to correspond to my image. Firstly, I don't have the choice 'WorldView-3' in the 'Pre Defined Filter Fuction' field of the Spectral Resampling Parameters. So I use the User Defined Filter Fuction and then, I select the WorldView-3.sli file from the folder '...ENVI\ENVI52\resource\filterfuncs'. But when I try to run the Spectral Angle Mapper tool, I got this error message: 'Problem: The input spectrum does not contain th...
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2880 |
by Deleted User16 Nov 2017 12:32 PM |
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8 Replies and 2798 Views
Adding lat/lon data to header files 2798 8
Started by Deleted User
Hello! I work with OceanColor MODIS, and Sentinel3A products, which can only be opened in ENVI as an HDF5 file format. When I open the HDF5 files, and display them, I can add the geo-coordinates. However, that geo-reference is lost when I save the HDF5 file as an ENVI file (giving me a .dat), and when I manipulate the images. I want to apply the geo-reference information from the original image to my end-product images, so that I always have a georeferenced image. How do I do that I have tr...
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2798 |
by Deleted User02 Nov 2017 10:12 AM |
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1 Replies and 1473 Views
Restore Training Files Example Based Classification 1473 1
Started by Deleted User
I have to re run the export of Example Based Classification but I forget exactly what parameters I used for scale and merge. I already ran one output and am wondering whether there is some sort of a log file stored somewhere that would give me that information I forgot to uncheck the 'Merge Adjacent Features' box and the output is uneditable in ArcMap for my purposes. ~Natasha
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by MariM02 Nov 2017 09:37 AM |
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10 Replies and 5287 Views
Radiometric Calibration/FLAASH problem with WV-2 Imagery 5287 10
Started by Deleted User
Aloha,
I'm trying to correct some WV-2 imagery (Digital Globe Standard2A) for atmospheric effects and to generate a surface reflectance image.
My steps in ENVI 5.1:
1) Radiometric Calibration
2) FLAASH
Unfortunately I get a blank output image after step 1. I've tried running the Radiometric Calibration tool in ENVI 4.8 and 5.2 as well, but in those versions I need to first input gain and offset values for all 8 bands. I've looked for these values in the .IMD file, but have not found them yet.
D...
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by Deleted User20 Oct 2017 02:44 PM |
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1 Replies and 2403 Views
Using FLAASH with RapidEye Level 3A image 2403 1
Started by Deleted User
Hello, I am trying to perform an atmospheric correction on RapidEye Level 3A data. From the product specification, I could derive the delivered product DN represent radiance in 1/100th of a W/m² sr ym ('This scaling converts the (relative) pixel DNs coming directly from the sensor into values directly related to absolute at sensor radiances. The scaling factor is applied so that the resultant single DN values correspond to 1/100th of a W/m2 sr µm.'). With that information, I choose 0.01 as t...
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2403 |
by MariM12 Oct 2017 12:26 PM |