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5 Replies and 59 Views FLAASH  59  5 Started by  Shuangyan He When I tried to using ENVI FLAASH to do the atmospheric correction for MISR data over water, it reminded me to input the 'filter Function File' in Multispectral Settings. After I input the sensor spectral response file, it reminded me the error of 'Attempt to subscript FF_WL with is out of range'. Is this because the MISR sensor has limited bands, as it only has four bands of 446, 558, 672 and 866nm Thanks!
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by  Mari MinariJump to last post
27 Apr 2017 01:30 PM
1 Replies and 62 Views Intrepretation of MNF eigenvector matrix  62  1 Started by  Rami Piiroinen Hi all, I performed minimum noise fraction transformation on a hyperspectral image with 129 bands. This produces 129 new bands, as it should. Okay, then I get the eigenvalues that I can use to interpret which bands contain information and which bands contain noise. Now I need to understand which bands constituted most to each new MNF band. To my understanding we need to look at the eigenvector matrix to see the 'loading' from each original band. But, which way should we look at the matrix...
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by  Mari MinariJump to last post
26 Apr 2017 02:12 PM
1 Replies and 22 Views ASTER L1T FLAASH Error  22  1 Started by  Praveen Kumar Hi, FLAASH module is throwing error, when I want to do atmospheric correction on VNIR and SWIR bands of ASTER L1T . The error is 'Input image has more bands (9) than expected for the selected sensor (14). Please check the sensor type or set to UNKNOWN-MSI if using a custom filter function'. What can be the cause for the error Thanks.
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by  Mari MinariJump to last post
26 Apr 2017 06:55 AM
0 Replies and 14 Views Convert radiance to reflectance  14  0 Started by  Katie I'm working on a project using hyperspectral data collected in a greenhouse. The data is in radiance (mW/m^2*2str*nm) and I'm trying to convert this to reflectance. We did take images of the calibration board before collecting the data. This white and dark calibration board is in the first image but none of the subsequent images. What would be the simplest way to convert the data to reflectance (I don't have the license for FLAASH.)
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25 Apr 2017 10:37 AM
1 Replies and 68 Views Generate Point CLoud Error  68  1 Started by  Alexandra I've been testing Generate Point Cloud from stereo images on WorldView-1/2, GeoEye and QuickBird data in ENVI 5.4. But in most the cases ENVI returns message "Generating point clouds requires at least two rasters in the supportes formats", while all the images contain RPC, overlap more than 50 and listed in supported data types. Exporting data to ENVI format with a generic RPC sensor model doesn't help. What can be the cause of the error Are there any limitations for this tool not l...
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by  Peg ShippertJump to last post
17 Apr 2017 01:12 PM
3 Replies and 60 Views Computing Vegetation Indices from Difference Landsat Sensors  60  3 Started by  Neelum I am working to estimate Above Ground Biomass (AGB) using ground sample data and then intending to work out its potential relationship between different vegetation indices like NDVI, RVI, DVI, SAVI, MSAVI etc. This relationship will be ascertained using regression equation. Resultantly, I will be able to predict AGB of earlier date after choosing suitable index to proceed with. I am using images from two different sensors, Landsat 8 OLI (January 2017) and ETM (January 2007) to derive above note...
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by  NeelumJump to last post
15 Apr 2017 07:23 AM
4 Replies and 36 Views rotate raster does not behave as expected  36  4 Started by  Andy Kellett Hi, I am trying to rotate a large orthophoto with row crops to see the effect that will have on susceptibility to moire when I resize. I applied rotations of 17 and 23 degrees in the rotate/flip raster tool. In both instances I can see small changes in the image at small scales (fine patterns in the edges of the rows changed) but the overall row angle remained exactly the same. I expected the whole image to rotate by the amount I entered, and so I expected to see the row angle noticeably chan...
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11 Apr 2017 12:17 PM
1 Replies and 34 Views image translation while apllying a second mask  34  1 Started by  max rouch Hello, First of all, sorry if the question is stupid, but I am still a beginner in remote sensig, I work with ENVI 5.1 on Landsat 8 images. I want to apply cloud masks on a same image ( a NDVI created from landsat 8 bands ). I created the cloud masks from the QA band of Landsat 8, the first cloud mask is a classic one, made for masking the clouds of the image, the second one correspond to the opposite of the cloud mask of another image, the purpose here is to retrieve the pixels that are without...
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11 Apr 2017 02:21 AM
0 Replies and 29 Views Fmask Cloud Cover Overestimation  29  0 Started by  Alexandra I've been testing Calculate Cloud Mask Using Fmask tool in ENVI 5.4 on Sentinel-2 and Landsat-8 data and results have been unsutisfactory. Algorithm tends to overestimate cloud cover and classify bright soils, snow, artificial structures and sometimes even vegetation as clouds. Futhermore, shadows stay undetected, while original algorithm detects cloud shadows as well. Additionally, different configuration parameters doesn't have any affect on results. Have somebody expirienced the same proble...
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10 Apr 2017 08:58 AM
3 Replies and 28 Views ML classification performing process: how pass the statistics from a roi  28  3 Started by  Lorenzo Bernardi Hi all, i am trying to perform a ML classification using ENVI API ENVIMaximumLikelihoodClassificationTask. I had seen the example where it is used a vector to calcolate the needed statistics. How implemenmt the same ML workflow using a set of ROI in xml or envi classic .roi format
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06 Apr 2017 07:00 AM
1 Replies and 26 Views How create a lookup array for the ENVI_DO_IT Net Neural Classification  26  1 Started by  Lorenzo Bernardi Hi all, i need to perform a Net Neural Classification using EVI:NEURAL_NET_DOIT api function. My input raster is a 7 bands ENVI file (.dat extension) and my training ROI file has 5 class (vegetation, water, sand, groung, build). Full code follows: COMPILE_OPT IDL2 envi ;, /restore_base_save_files ENVI_BATCH_INIT output_nn = classfication_output output_nnrule = rulke_classification_output ; variabili globali inputsms = myraster ; aggiungere apertura file raster con est...
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06 Apr 2017 05:19 AM
5 Replies and 33 Views How modify the pixels value inside a ROI  33  5 Started by  Lorenzo Bernardi Hi all, i need to execute a change detection with the certainty of obtaining a result in term of change from vegetation class to built class. I use the SVM classifier. In order to obtain at least a result i would artificially change the pixels values inside a ROI. Thank you for any Suggestion
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04 Apr 2017 03:02 AM
0 Replies and 29 Views Advanced use of idlpy bridge: open-close license management  29  0 Started by  Lorenzo Bernardi Hi all, i have a python script that calls and executes some python function making idl processes following the'instruction') syntax. More in detail, i have a set of function making "radiometric correction", "pansharpening" "layer stacking", and so on. I make the import of idlpy module ad the begin of my file. The problem is that license remains busy throughout the execution duration. I try also to make the import only from the function. There is a way to im...
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03 Apr 2017 03:16 AM
1 Replies and 29 Views background pixels in classification  29  1 Started by  AYSIN KUZUCU Hi, I want to classify SPOT 7 multispectral image in ENVI 5.1. After I created subset image of my study area using ROI, background data (the pixel values outside of the ROI data) occurred. Background data has zero pixel value. In order to mask background pixels, I created ROI from band thresholds and chose thresholds parameters for all bands as min value=0; max values=0 and then saved ROI to .xml. I selected the subset image as classification input file. I imported "mask ROIs xml"...
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31 Mar 2017 05:25 AM
10 Replies and 45 Views Resizing raster cuts and shifts image  45  10 Started by  Andy Kellett Hi, Has anyone seen this I'm resampling a moderate raster (118 MB, 8-bit grayscale) 8 --> 1 with cubic convolution. When its done, the image has been sliced vertically and re-shuffled. I can't show the data, but schematically it looks like this: before after abcdefghijk defghijkabc abcdefghijk defghijkabc abcdefghijk defghijkabc abcdefghijk defghijkabc ...
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by  Mari MinariJump to last post
30 Mar 2017 10:38 AM
0 Replies and 28 Views Removal the shadow effect in hyperion images  28  0 Started by  Narayan kayet How to remove shadow effect in Hyperion imagein hilly region area
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28 Mar 2017 11:11 PM
1 Replies and 25 Views Reprojecting and Resizing Rasters  25  1 Started by  Brianna Lind I have two raster files, A and B (see Table below). I am looking to reproject B to the same projection as A, and also resize (aggregate) pixels in B to the same size as A (0.5 x 0.5 degrees) so they can be stacked. I have been trying to reproject raster B to the same gcs as A using the "Reproject Raster Tool" and selecting the coordinate system to reproject to using the "import from existing data set icon". This works fine, but I've noticed that when B is projected into degr...
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26 Mar 2017 10:46 AM
1 Replies and 29 Views ENVI no longer working with OSX Sierra  29  1 Started by  Alexander Zawacki Hi all, I've been running ENVI Classic 53 on OSX 10.11.3 El Capitan using X Quartz 2.7.9 without issue; however, after updating to Sierra this afternoon, I can no longer get ENVI to open. That's an issue. Any suggestions Thanks.
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25 Mar 2017 07:17 PM
1 Replies and 25 Views georeference a flipped image  25  1 Started by  Tom Farr Hello, I have an image that is flipped E-W. I have the lat/lon of the upper left pixel and the pixel sizes in degrees. When I try Edit header/Spatial Reference, I get the same flipped image with incorrect lat/lons in the image. If I Rotate/Flip the image first, using Transpose and Rotate 270 deg. I get the image right side up, but then when I tried telling ENVI which pixel was which lat/lon, it came out wrong again. I'd rather do only one operation on the image as I have many more with the same...
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21 Mar 2017 06:02 PM
4 Replies and 28 Views Replace bad values Error  28  4 Started by  Adam Podhrázský I have set of Landsat 7 images. I need to remove "black lines" from images and i use Remove bad Values tool. Tool works fine on most images but when i try to use it on some of them i get error like: "dem_bad_data_doit: An error has occured during processing Error: "TRIANGULATE: Points are co-linear, no solution" The result may be invalid. What's the problem And how to fix it Why some of images are processed fine and some not They are from same source (https://earthe...
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21 Mar 2017 06:53 AM
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