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4 Replies and 4501 Views CONVERT ASTER L1T DN VALUES TO RADIANCE  4501  4 Started by  Deleted User Hi, I have ASTER L1T data that I need to work on and seems to be in DN values. I have read from AST_L1T user guide and they state that to convert them it needs to use the formula: Radiance at-sensor = (DN value – 1) x Unit conversion coefficient where for that case Unit conversion coefficient for the data from HDF file are: Band 1: 0.676000 Band 2: 0.708000 Band 3: 0.862000 the DN values are: Band 1 0 255 Band 2 0 255 Band 3 0 251 I understand that when app...
4 4501
11 Aug 2016 05:52 AM
2 Replies and 1891 Views Obtaining Initial Visibility value For FLAASH  1891  2 Started by  Deleted User Hi, May I be informed how one can obtain the initial visibility value (km) for the ASTER L1T image when doing Atmospheric correction using FLAASH module. Regards
2 1891
01 Aug 2016 07:44 AM
1 Replies and 4766 Views Convert Bit Depth of Raster Image  4766  1 Started by  Deleted User Hi, I would like to know if there is a simple way of converting the bit depth of an image in ENVI. I am used to using ArcGIS products, but we have recently received ENVI 5.3 and are still getting used to this product, so it may be a case of different terminology between the programs or they way I'm looking at it but help would be appreciated. We need to convert 100's of images (TIFF format) from 16-bit to 8-bit and it is a slow process. I'm hoping we can take advantage of ENVI's 64-bit operati...
1 4766
26 Jul 2016 07:49 PM
2 Replies and 1871 Views transect from vector  1871  2 Started by  Deleted User I've 'graduated' to ENVI 5.3, but can no longer find the capability to create a transect using a vector as the guide. In ENVI 4, I used the Spatial Profile Tool, but that's nowhere to be found. Anybody have a solution Thanks, Tom Farr, JPL
2 1871
26 Jul 2016 02:34 PM
1 Replies and 1936 Views Question About Co-Occurrence Grey Level Quantization  1936  1 Started by  Deleted User Hi, I'm using ENVI 5.3 to run grey level co-occurrence texture analyses on a series of LiDAR-derived canopy height models. I have a question regarding the "Grey Level Quantization Levels" feature of the ENVI co-occurrence tool: Do the grey level quantization levels represent a limit in the number of values being considered by the matrix I ask because I'm working with a collection of 8-bit rasters with values ranging from 0-63. With an 8-bit pixel depth, my data represents just 63 of 2...
1 1936
22 Jul 2016 09:33 AM
1 Replies and 1965 Views Unmixing Image Fusion  1965  1 Started by  Deleted User I've high resolution UAV image in RGB band and Sentinel image for the same day. I would like to perform unmixing fusion to obtain fused image with high spectral and spatial resolution.Is it possible to carry out unmixing fusion in ENVI If it is what are the steps
1 1965
21 Jul 2016 11:41 PM
11 Replies and 2231 Views No data "Bad band" After FLAASH Corrections  2231  11 Started by  Deleted User Hi, I have been trying to do atmospheric correction of ASTER VNIR-SWIR data interval but in a result I get band 9 to have no data (zero values or bad band). What might be the cause of that because I have asked the data provider and they have said there is nothing wrong on there side. Then checked several other data the same problem appears. Regards
11 2231
21 Jul 2016 09:24 AM
4 Replies and 2030 Views ENVI Layer Stacking Doit  2030  4 Started by  Deleted User Hi all, I'm creating a script to automatically stitch together one band rasters of the same dimensions into one file with multiple bands. Those who will be using this are using an earlier version of ENVI that doesn't include the new ENVITask way of doing this. When I run the procedure up to the ENVI stacking DOIT task, I get the following error: "Error: 'Array dimensions must be greater than zero.' The result may be invalid" The line with the DO_IT command is: ENVI_DOIT, 'ENVI_LAYER...
4 2030
19 Jul 2016 11:46 AM
3 Replies and 3449 Views Exporting images at high resolution  3449  3 Started by  Deleted User Hi all, I'm wondering if there's a workaround for exporting images from ENVI (or through IDL) at high resolution. I'm working with ENVI 5.3.1. From what I can see, my options for exporting an image from ENVI with all enhancements included (e.g. stretching, sharpening, etc.) are: Export at 72 dpi (Chip view to file; Export view to image file) or Export view to Geospatial PDF and choose the export resolution. Are there any more options than the 2 above I need at least 300 dpi resoluti...
3 3449
11 Jul 2016 12:13 PM
1 Replies and 1571 Views Reading Push-Broom sensor row/frame coordinate data  1571  1 Started by  Deleted User I'm working with a push-broom style hyperspectral imager that outputs separate coordinate and aircraft yaw/pitch/roll information for each row (frame) of the generated image. That information is contained in a separate "Navigation" text file. The header file (below) which accompanies the image does not provide any coordinate information. Can anyone give me any general tips on how to pass the row coordinates, and yaw/pitch/roll information to ENVI so I can get the image to display corre...
1 1571
08 Jul 2016 03:03 PM
4 Replies and 2178 Views Unable to apply cloud mask (fmask) to multispectral source image  2178  4 Started by  Deleted User I am using the 'Feature Extraction' tool from the Feature Extraction module available in the ENVI 5.3 Service Pack to calculate a cloud mask using Fmask following the instructions from the Harris Geospatial website: https://www.harrisgeospatial.com/docs/calculatecloudmaskusingfmask.html I am able to create the cloud mask from the multispectral (converted to reflectance) and thermal (converted to brightness temperature) bands, but when I attempt to apply the cloud mask to the multispectral source...
4 2178
01 Jul 2016 10:51 AM
1 Replies and 1970 Views Use ENVI Co-Occurrence FIlter Tools with ArcGIS Grid  1970  1 Started by  Deleted User Hi, I'm new to ENVI software, but I've got one simple thing that I'm hoping to do! I'm trying to perform a texture analysis on a series of LiDAR-generated canopy height models in either ENVI or ArcGIS. The height model rasters are in ArcGIS GRID format, and I'm hoping to analyze the texture of a value field representing the height of the forest canopy. What is the easiest way to go about this Is there any way to just import the co-occurrence filter tools (specifically mean, entropy, correlatio...
1 1970
30 Jun 2016 07:36 AM
1 Replies and 2991 Views Quick map option  2991  1 Started by  Deleted User Hi, Where can i find the quick map option like the one in previous version of envi
1 2991
29 Jun 2016 03:18 AM
3 Replies and 2686 Views Creating Contours on ENVI Raster DEM  2686  3 Started by  Deleted User Hi all, I've seen the ENVI Contour routines and function documentation, and saw that the input files seem to be bitmaps or .dat csv-like files. I would to create an automatic procedure from rasterized LiDAR data in ENVI image format. What would be the most efficient and effective way to get the ENVI Raster data in an acceptable form for the CONTOUR routine Many thanks, Jared
3 2686
28 Jun 2016 11:46 AM
7 Replies and 2567 Views FLAASH error: acc_called_t5set  2567  7 Started by  Deleted User Hi, I'm processing GOCI (Geostationary Ocean Color Imager launched by Korea) radiance data, and tried to use FLAASH to correct atmospheric effects.I know there are some requirements of the data format by FLAASH, so I converted the radiance data type to float, convert BSQ to BIL, correct the image coordinates. FLAASH failed and the following error poped up: ACC error: acc_called_t5set:read tape5 back in to check format. IDL error: Unable to apply format code F to input: "**********". 2...
7 2567
26 Jun 2016 07:40 PM
1 Replies and 1843 Views Sentinel image do not appear as it should be  1843  1 Started by  Deleted User I have imported a sentinel image in ENVI 5.3 and it appears as the image below. Why is this happening
1 1843
21 Jun 2016 03:02 AM
1 Replies and 1702 Views Change dark pixel to bright pixel  1702  1 Started by  Deleted User Hi, How can I inverse(negate) my PC by change the dark pixel to bright pixel after PCA For example in my PC3 the vegetation cover is displayed with dark pixels, in order for me to highlight the vegetation I want to display the vegetation cover with bright pixel, by tricking/change the eigenvector loading from negative to positive vice versa. How can I do that in envi Thank You
1 1702
14 Jun 2016 09:36 PM
1 Replies and 1858 Views flaash parameters  1858  1 Started by  Deleted User Hi, I have some questions about these FLAASH parameters: 1) In "Multispectral Settings" -> Kaufman-Tanre Aerosol Retrieval. Which Upper & Lower Channel should I put for SPOT 7 images 2) If I don't use multispectral settings, should I choose aeresol model/aeresol retrieval as none and water column multiplier=1 Thank you for your help. Regards
1 1858
14 Jun 2016 02:54 AM
1 Replies and 1786 Views Vegetation Suppression  1786  1 Started by  Deleted User Hi, I've done vegetation suppression on my landsat 8 image. The image have been processed and mask out the water. however after vegetation suppression I noticed that the Dn value of water is negative, (it should be 0 as i already mask it out). The statistic results of my min value is negative. how can I change that Can band math do the job if yes, what are the equation
1 1786
10 Jun 2016 11:44 AM
1 Replies and 2054 Views SVM Using RBF Kernel  2054  1 Started by  Deleted User I'm a new user of ENVI 5.1. I have a question about the implementation of the supervised classification method SVM. I'm trying to run grid search cross-validation in order to identify the optimal C and gamma parameters for the RBF kernel. Here are my questions: 1- How to select best kernel parameters for Radial basis function of SVM by grid search cross-validation using ENVI 5.1 2- I have sample areas. How do I separate these sample areas as training set, cross validation set and test set
1 2054
09 Jun 2016 01:35 AM
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Page 20 of 137 << < 1819202122 > >>