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1 Replies and 14 Views Georeferencing - Orthorectification - Mosaicking  14  1 Started by  Stavroula Giannakopoulou Hello! I' m trying to apply a methodology that icludes georefercing - orthorectification and mosaicking. First of all because of the fact that the stripes of my images have lost their georeference, i import the right georeference from the spatial reference of images that have more bands. After that, i don't know if i should orthorectify my images and how. Is it essential Finally, because my images iclude parts that are repeated, i want to create a mosaic with those stripes of images so i don't ...
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by  Mari MinariJump to last post
20 Feb 2019 11:10 AM
1 Replies and 12 Views How to calculate Nitrogen index (NDNI) from Micasense Rededge?  12  1 Started by  Stefanus Agung How to calculate Nitrogen index (NDNI) from Micasense Rededge
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by  Mari MinariJump to last post
18 Feb 2019 04:57 AM
2 Replies and 54 Views PCA-Forward PCA  54  2 Started by  Stavroula Giannakopoulou Hello, I'm trying to implement the PCA method. I chose the bands that i think that they don't contain noise and i implemented 'Forward PCA Rotation New Statistics and Rotate'. After that i implemented th 'Forward PCA Rotation Existsing Statistics' but i can't figure out what should i change in this method. Should i choose the PCs that i think that they contain the information that i needAnd after that i should implement the Reverse PCA with the bands that contain information so as to have a ...
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by  Stavroula GiannakopoulouJump to last post
14 Feb 2019 02:48 AM
4 Replies and 84 Views Represent pixels from different bands to an image  84  4 Started by  Stavroula Giannakopoulou Hello!I' m trying to represent at my image pixels from the same image but from different bads. In many bands i have very high values of reflectance because of the sensor. So i' m trying to find alla those pixels, which may be different from the one band to the other. Please let me know if you have any advice! Thank you very much!
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by  Stavroula GiannakopoulouJump to last post
30 Jan 2019 10:39 AM
1 Replies and 64 Views Reflectance formula for SPOT 6  64  1 Started by  mega I have tried to calculate manually from digital number to radiance for SPOT 6. The result is the same with Envi Tool that is from DN to radiance. But, when I calculate manually from radiance to reflectance, the result is not the same with Envi Tool. So, how the formula to Envi to calculate radiance to reflectance for SPOT 6
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by  Mari MinariJump to last post
24 Jan 2019 05:23 AM
23 Replies and 893 Views FLAASH ACC Error  893  23 Started by  kdsingh85
(Topic has multiple pages1 2 )
Hi Ben, I was trying to use FLAASH for my hyperspectral data atmospheric correction, but it is not processing any data and continuously showing error messages (ACC_AUTOCHAN: No water absorption channels selected). I fixed Error-1 by choosing water absorption band, but I never understand why it is still showing Error-2 (ACC error: convert7; IDL error: End of input record encountered on file unit:0); ACC_CONVERT7 ACC_HYPER2.... I am also attaching my FLAASH restore file. Let me know how I...
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by  Stavroula GiannakopoulouJump to last post
21 Jan 2019 11:35 AM
3 Replies and 69 Views Iterative SVM classification  69  3 Started by  Prabha Rupasinghe Hello, I am trying to iterate SVM classification for 100 outputs and I need classification error matrices for all 100 outputs so that I can perform some statistical analysis to compare time series. I need to do this for several time series for two sites, so I guess my only option is using IDL as this is lots of work to be done manually. I used the IDL example given in the link; for my images. I ch...
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by  Mari MinariJump to last post
16 Jan 2019 01:08 PM
2 Replies and 60 Views Convert an image with BSQ to BIL or BIP  60  2 Started by  Stavroula Giannakopoulou Hello!I have a very simple question about my image. It' s an image that is radiometrically corrected with bsq interleave. I want to convert it to bil or bip in order to correct it atmospherically with the FLAASH method, but I don't know how!Any advice will be very useful! Thank you very much in advance!
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by  Stavroula GiannakopoulouJump to last post
16 Jan 2019 10:10 AM
16 Replies and 2025 Views Access Denied - Verification Pending  2025  16 Started by  Lisa Upton Why did I receive an "Access Denied - Verification Pending" error message
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by  shilpi jainJump to last post
19 Dec 2018 10:12 PM
1 Replies and 771 Views Trouble Verifying Account  771  1 Started by  Claire Leyden I received a verification e-mail, but when I click on it, I'm prompted to login. Once I login I receive the message 'You are using an unverified account. Please verify your account by clicking on the link contained in the verification email that has been sent to you.'
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by  shilpi jainJump to last post
19 Dec 2018 09:47 PM
0 Replies and 19536 Views Access Denied - Verification Pending  19536  0 Started by  jeong hoon hyun As stated in the subject, why did I receive an 'Access Denied - Verification Pending' error message when I clicked 'Downloads' in my account page to download 'IDL'. How can my account be verified
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19 Dec 2018 03:35 AM
1 Replies and 132 Views BASE IS ARBITRARY error  132  1 Started by  kdsingh85 Hi, I can't open a file in ENVI associated with the below .HDR file. It is showing 'BASEISARBITRARY' error. Let me know what is this 'BASEISARBITRARY' means Thanks, Keshav ---------------.HDR File-------------------- ENVI description = &91;' Georeferenced Image built from input GLT. &91;'Mon Sep 17 16:36:09 2018'&93;'&93; samples = 1326 lines = 932 bands = 150 header offset = 0 file type = ENVI Standard data type = 4 interleave = bip sensor type = Unknown byte order ...
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by  Mari MinariJump to last post
03 Dec 2018 07:17 AM
4 Replies and 165 Views Sub-pixel classification to Sentinel 2 images  165  4 Started by  Prabha Rupasinghe Hi, I am trying to use sub-pixel classification to Sentinel 2 image to map an invasive plant. I tried spectral hourglass wizard and tried to modify the endmembers by comparing the ROIs with my image to be classified. I need only 5 classes for my end product. Should I use only the endmembers for those 5 classes or should I use all the possible endmembers Also, the SAM classification results at the end is very poor. Can I use another set of ROIs I created to re-run another classification method (...
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by  Prabha RupasingheJump to last post
10 Oct 2018 10:41 AM
1 Replies and 286 Views TOA conversion  286  1 Started by  zarifet I have a set of Landsat images (TM, ETM and OLI) for change detection analysis and I would like to convert Top of the Atmosphere OLI images from 16-bit to 8-bit. How to do it with ENVI 5.3. Thank you in advance
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by  Mari MinariJump to last post
20 Sep 2018 08:37 AM
4 Replies and 972 Views Combining classified images in ENVI  972  4 Started by  Prabha Rupasinghe Hello, I am using Sentinel 2 images for image classification for a pretty large area. So I had to break the images into smaller blocks before classification and process them separately. Now I want to do a change detection for the entire area at once. Is there a way to combine these blocks into a one classified image in ENVI I could not find a specific tool for that. I tried to do it with ArcGIS, but couldn't find a good way to do it. I really appreciate any help on this. Thank you!
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by  Mari MinariJump to last post
21 Aug 2018 04:07 PM
1 Replies and 521 Views Color a number of pixels in a grayscale image  521  1 Started by  Malcolm Druett I have grayscale images and wish to highlight specific, fairly large groups of pixels in each image, e.g. by re-coloring those pixels. I have arrays of all the pixels to highlight for each image. Overplotting with a transparent mask seems like an arduous way to go about this. Is there a better way Thanks.
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by  Mari MinariJump to last post
05 Jul 2018 06:54 AM
15 Replies and 476 Views ENVI - Estimate Noise Statistics From Data - Error  476  15 Started by  Vicente Jeria Hi everyone! I have this problem: when I am calculating the Estime Noise Statistics From Data in ENVI, I get the following error: 'The number of the pixels in the shift difference spatial subset should greater than the number of input bands. Please enlarge the spatial subset for noise statistics'. In other topic, I read that this problem may occur due bad bands, maybe identical min and max values or values equal to 0 and that I have to edit the header of image. In this sense, I don´t know how...
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by  Mari MinariJump to last post
06 Jun 2018 06:33 AM
0 Replies and 20067 Views Problem with the projection of Worldview 3 image  20067  0 Started by  Tharindu Abeysinghe Hi, I have a WorldView 3 image with multispectral (only 8 bands; Coastal, Blue, Green, Yellow, Red, Rededge, NIR1, NIR2) and panchromatic band. I can open one (either multispectral or panchromatic) of them without any problem in ENVI 5.4. But when I open both images in same ENVI window, both multispectral and panchromatic bands get distorted (looks like both are projected to a different coordinate system). Both images are in Geographic coordinate system- GCS_WGS_1984, Datum- D_WGS_1984. Can ...
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14 May 2018 07:21 PM
6 Replies and 632 Views SVM classification for multiple scenes with one set of ROIs  632  6 Started by  Prabha Rupasinghe I am trying to classify Sentinel 2 images for a very large area using the SVM classification. Currently, I can only process an area about 25 sq km at a time to get the desired accuracy. I also explored other classification methods but only SVM gives me good accuracy for my purpose. As my area is very large, it takes me ever to define ROIs for small pieces of images. Is there a way I can use a single set on ROIs for all my pieces Or is there any other method to make this process easier and fast...
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by  Prabha RupasingheJump to last post
11 May 2018 10:47 AM
1 Replies and 494 Views DarkSubtractionCorrection Task  494  1 Started by  Russell Ives Running the 'DarkSubtractionCorrection' task in an API on reflectance values from a calibrated Worldview 2 data where the image boundary data has a pixel state of 1 are being calculated as negative values on the output raster. How do I stop this Here is the section of code doing the calculation (with forcing 'data ignore value' param). ;***Add data ignore value to the metadata **** IF (metadata.HasTag ('data ignore value')) THEN BEGIN metadata.UpdateItem, 'data ignore value', 0. ...
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by  Mari MinariJump to last post
20 Apr 2018 12:26 PM
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