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0 Replies and 342 Views
Convert radiance to reflectance 342 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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342 |
25 Apr 2017 10:37 AM |
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1 Replies and 253 Views
Generate Point CLoud Error 253 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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1 |
253 |
by Peg Shippert 17 Apr 2017 01:12 PM |
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3 Replies and 222 Views
Computing Vegetation Indices from Difference Landsat Sensors 222 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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3 |
222 |
by Neelum15 Apr 2017 07:23 AM |
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4 Replies and 260 Views
rotate raster does not behave as expected 260 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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4 |
260 |
11 Apr 2017 12:17 PM |
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1 Replies and 293 Views
image translation while apllying a second mask 293 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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1 |
293 |
11 Apr 2017 02:21 AM |
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0 Replies and 337 Views
Fmask Cloud Cover Overestimation 337 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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337 |
10 Apr 2017 08:58 AM |
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3 Replies and 273 Views
ML classification performing process: how pass the statistics from a roi 273 3
Started by Lorenzo Bernardi
Hi all, i am trying to perform a ML classification using ENVI API ENVIMaximumLikelihoodClassificationTask.
I had seen the example https://www.harrisgeospatial.com/docs/ENVIMaximumLikelihoodClassificationTask.html 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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3 |
273 |
06 Apr 2017 07:00 AM |
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1 Replies and 288 Views
How create a lookup array for the ENVI_DO_IT Net Neural Classification 288 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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1 |
288 |
06 Apr 2017 05:19 AM |
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5 Replies and 284 Views
How modify the pixels value inside a ROI 284 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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5 |
284 |
04 Apr 2017 03:02 AM |
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0 Replies and 292 Views
Advanced use of idlpy bridge: open-close license management 292 0
Started by Lorenzo Bernardi
Hi all,
i have a python script that calls and executes some python function making idl processes following the IDL.run('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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292 |
03 Apr 2017 03:16 AM |
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10 Replies and 189 Views
Resizing raster cuts and shifts image 189 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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10 |
189 |
by Mari Minari30 Mar 2017 10:38 AM |
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268 |
28 Mar 2017 11:11 PM |
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1 Replies and 250 Views
Reprojecting and Resizing Rasters 250 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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1 |
250 |
26 Mar 2017 10:46 AM |
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1 Replies and 271 Views
ENVI no longer working with OSX Sierra 271 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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1 |
271 |
25 Mar 2017 07:17 PM |
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1 Replies and 221 Views
georeference a flipped image 221 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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1 |
221 |
21 Mar 2017 06:02 PM |
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4 Replies and 247 Views
Replace bad values Error 247 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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4 |
247 |
21 Mar 2017 06:53 AM |
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8 Replies and 539 Views
Error opening Sentinel 2 539 8
Started by Lorenzo Bernardi
Hi all,
i am trying to import Sentinel 2 dataset.
I downloaded the file S2A_MSIL1C_20170313T093031_N0204_R136_T33SXR_20170313T093510.zip.
How can i open this file into ENVI 5.4
Thank you for any succestion.
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8 |
539 |
17 Mar 2017 05:11 AM |
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1 Replies and 229 Views
WV3 Radiometric Calibration 229 1
Started by PY Chan
I am working on a WV2 and a WV3 image, with ENVI 5.2.
The WV2 one can be convert into either radiance or reflectance by using the Radiometric Calibration Tool.
However, for the WV3 image, it can only be converted into Radiance, but NOT reflectance.
After looking at the metadata, I have found that the irradiance data is missing for the WV3 image, so I believe that is why ENVI cannot convert it into reflectance
Is there any solutions for the situation or what steps should I take to get it to refl...
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1 |
229 |
15 Mar 2017 10:35 PM |
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2 Replies and 222 Views
majority/mode from bands 222 2
Started by niedziellak
Is there any tool, or band math function, that can compute the majority or mode from bands of the image I mean that I want to know for each pixel, the value that is most frequent through all the bands of the image.
For example: Image with 3 bands, for pixel(i,j) values are:
b1=2, b2=3, b3=3
the result should be: majority=3
Actually I need this to combine different classification results and for each pixel select the most frequent class.
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2 |
222 |
15 Mar 2017 04:52 AM |
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1 Replies and 232 Views
Import Ascii ROI file 232 1
Started by Geoff Banks
I have an ROI file in ascii format, exported by ENVI. How can I import this back into envi
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1 |
232 |
14 Mar 2017 03:39 AM |