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2 Replies and 1516 Views
Steps to calculate NDVI in QuickBird 1516 2
Started by Deleted User
HI,
I calibrated a QuickBird image to convert DN to radiance using the function in the menu. My QuickBird image is already orthorectified and I need to calculate NDVI now. Should I use FLAASH to correct to reflectance before calculating NDVI Is FLAASH the tool
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2 |
1516 |
12 Jun 2012 08:26 AM |
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1 Replies and 1165 Views
problem in overlaying shape files 1165 1
Started by Deleted User
Dear Users My name is Giacomo Fontanelli and I use Envi 4.8. Every time I try to overlay a shape file (.shp) upon a SAR image here comes an error message "File: C:\ namefile.shp, An error occurred converting this file to an EVF. Error: Array dimensions must be greater than 0". To overlay this file I have to save it as a .dxf (from my GIS) and converting it in .evf. Thank you very much for your suggestions
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1 |
1165 |
11 Jun 2012 03:03 PM |
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1 Replies and 1995 Views
make a map using envi 4.7 1995 1
Started by Deleted User
does anyone here knows how to do a map in envi 4.7..
usually i do the mapping at arcgis.. and now i want to try out in making map using envi4.7
tq!
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1 |
1995 |
09 Jun 2012 09:47 AM |
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1 Replies and 1161 Views
Constructing a confusion matrix on an already classified image 1161 1
Started by Deleted User
Hello,
I produced a classified image using a decision tree through R. The output from R was a .envi file that I converted to a .dat. I would like to use ENVI's confusion matrix tool to evaluate the results of the classification. I have .evf files to use for ground truth ROIs. However, ENVI tells me I must use an ENVI classification in order to construct a confusion matrix.
Is there a way to remedy this Should I somehow reclassify the classified image in ENVI first Not sure how to do thi...
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1 |
1161 |
08 Jun 2012 08:27 AM |
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2 Replies and 1754 Views
how to process mod04- to extract aerosol optical thickness 1754 2
Started by Deleted User
hello. im SYAFIQA AND I'M new here. wanna ask some question. actually im doing a research. which is pm10 concentration using modis image. the problem that im having is with the algorithms. i have found some of the algorithms to extract pm10.. but the algorithms need the value of AOT. which is oerosol optical thickness or aerosol optical depth. i have ask mr devin. how to extract aod in image. he told me to download the mod04. i already download it. but while georeferencing, there's a lot proces...
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2 |
1754 |
07 Jun 2012 12:52 PM |
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1 Replies and 1223 Views
Problem in converting the map projection 1223 1
Started by Deleted User
Hello, I have create a mosaic of two images and I was trying convert its projection system to EGSA87. My steps were as followed: map > convert map projection > select the image> change projection to Hellenic geodetic reference system 87. However, when overlaying my vector layers which are already in the desirable projection system, the image is not exactly at the same position with them. I am not sure what the problem is can you please indicate me what I am doing wrong
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1 |
1223 |
07 Jun 2012 05:10 AM |
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1 Replies and 1296 Views
Problems displaying proper spatial extent of SLC SIR-C images 1296 1
Started by Deleted User
Hello, I'm unable to properly synthesize SIR-C (SLC) img files using ENVI 4.2. When I view the final SLC product in ENVI (post-SIR-C-synthesizing), it covers a significantly smaller spatial extent than I expect based on the overlay image of SLC data on the earthexplorer.usgs.gov website (where the data are housed).
I was curious if this was a common problem encountered with SIR-C SLC data, and whether anyone might have an idea of how I could fix this issue. I've had no issues displaying the co...
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1 |
1296 |
06 Jun 2012 10:10 AM |
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2 Replies and 1820 Views
Problem with ROI's in ENVI 1820 2
Started by Deleted User
Hi Everyone,
I am having some difficulties using the Region of Interest (ROI) tool in ENVI. I am using a time series collection of landsat data squares each covering the same area within the Peruvian Amazon. Im looking at NDVI variations of a spectrally homogeneous area of the region. I want to create an ROI that can be re-opened for every separate image to compare the NDVI variations over time. However whenever i create a new ROI it only lets me open it on the data square it was created on and...
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2 |
1820 |
05 Jun 2012 01:51 PM |
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2 Replies and 1302 Views
Some 'how to do it in ENVI 5 questions 1302 2
Started by Deleted User
Hello,
I find the new ENVI 5 interface generally very nice but have troubles finding a few things or doing certain things...
1. Is it possible to get the crosshairs in all open views (e.g. have 4 crosshairs in a 2x2 view) That'd be more helpful for comparing images.
2. Related to that, is it possible to have linked views, then open the cursor value and have the data from all open views returned The only workaround this I found would be load all the data I want to investigate with the cursor...
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2 |
1302 |
05 Jun 2012 01:17 PM |
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3 Replies and 1541 Views
Geolocation error when opening geotiff 1541 3
Started by Deleted User
I am opening a geotiff file in ENVI and everything looks fine - except for it being off > 1km, which is a lot when working with 4m data... The data opens correctly in ArcGIS. I am checking it against Google Earth, using an easily recognizable feature, and the coordinates for the feature are approximately the same as in Google Earth when opening the geotiff file in ArcGIS, but quite a bit off when opening it in ENVI. Probably one way around would be to use ArcGIS for all processing, but I am more...
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3 |
1541 |
05 Jun 2012 11:58 AM |
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2 Replies and 1150 Views
about Tasseled Cap of LandSat5 TM 1150 2
Started by Deleted User
Hi,
I have read the help in ENVI about Tasseled Cap, and download the paper of Crist(1984) and Crist(1986) . I use the transformation value in this two papers to caculate the KT and the result is different from ENVI's result.
Is there anyone can give a explaination Who can give a list of transformation value used in ENVI for landsat5 TM
best regards,
wyc
6/2/2012
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2 |
1150 |
31 May 2012 10:51 PM |
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1 Replies and 1219 Views
Tutorial Data 1219 1
Started by Deleted User
Hello,
I'd like to practice various image correction approaches in ENVI, specifically geometric, radiometric, and atmospheric. I have run through the tutorials provided by ENVI online. They are all good and well but I would like to give it a shot on my own.
What I would like to do is retrieve imagery for each of these correction processes. Most of the Landsat data I find has already been geometrically corrected. The areas for which non-registered Landsat imagery (L0) is available are those for...
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1 |
1219 |
29 May 2012 10:42 PM |
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3 |
1178 |
29 May 2012 06:22 PM |
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0 |
1003 |
29 May 2012 06:22 PM |
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4 Replies and 966 Views
Save Display Group? 966 4
Started by Deleted User
Hi,
In ENVI 5, is there a way to save the content of the display window and its settings, so that if I have several files- images and classifications- loaded into the display I can save that setup and reload it to work on later without having to start over I think 4.8 had that feature...
Thanks!Kate
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4 |
966 |
29 May 2012 02:45 PM |
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2 Replies and 1104 Views
Masking for n-D Visualizer Input 1104 2
Started by Deleted User
Hello,
I created a mask for an image from an ROI of the unwanted pixels. I would now like to view all of the pixels in the image, except for the masked ones, in the n-D visualizer. This seems like it should be pretty straightforward but I haven't been able to figure it out. I applied the mask I created to the original file and have been trying to use this new file as the input data for n-D, but it still shows me pixels from the entire image, including the unwanted ones.
Can anyone advise
T...
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2 |
1104 |
29 May 2012 02:07 PM |
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3 Replies and 1274 Views
Cutline Mosaic .anz/.ann issue 1274 3
Started by Deleted User
Hello,
I am trying to perform cutline feathering in ENVI 5. the tool requires a .ann file, however, ENVI 5 seems to only save annotation in .anz format. is there a way to convert anz to ann, or perhaps a way to get the mosaic tool to read .anz
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3 |
1274 |
29 May 2012 09:29 AM |
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1 Replies and 1635 Views
FLAASH Landsat 7 ETM 1635 1
Started by Deleted User
Hello!
I am trying to do some atmospheric correction on Landsat 7 ET´M images using FLAASH.
I have been getting this error:
Filter Function File:
C:\Program Files\ITT\IDL70\products\envi45\filt_func\tm.sli does not contain enought bands for the given input image. Please check the sensor type.
I don´t know if there is a specific function for ETM sensor or if the function tm.sli is correct for ETM.
I think i am going wrong somewhere in my input parameters shown below:
Pro...
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1 |
1635 |
28 May 2012 04:52 AM |
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2 Replies and 959 Views
NDVI from QuickBird 959 2
Started by Deleted User
Hi,
Do I need to convert raw QuickBird data (which is relative reflectance) to reflectance before running the tool TRANSFORM > NDVI Or is ENVI doing that by itself
Thanks!
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2 |
959 |
25 May 2012 11:10 AM |
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1 Replies and 1240 Views
Adding band 1240 1
Started by Deleted User
Hello, I would like to use the classification of satellite imagery in addition to the spectral indices, which I saved in separate files. The problem is that for the classification I can only select one file. I wanted to connect the spectral indices as additional band to the file, where spectral bands of satellite imagery are stored, but unfortunately I do not know how. Could someone please advise me thanks
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1 |
1240 |
25 May 2012 09:39 AM |