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5 Replies and 2656 Views
Band Math Expression 2656 5
Started by Deleted User
Hi, I am very new to this forum and do not have any programming background. I need to calculate the (NDWI....WATER INDEX) and (NDSI.....SOIL INDEX) by using the Landsat TM and ETM images.kindly help me by suggesting something, I will be greatly thankful to you all.
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5 |
2656 |
22 Jun 2010 11:52 AM |
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0 Replies and 1122 Views
georeferencing from GLT 1122 0
Started by Deleted User
I have lat/lon bands for my images, which provides lat/lon values for the upperleft corner of each pixel (not the centre). The pixel size is not regular, so I do not have pixel centre coordinates. I would like to georefence the images using these lat/lon bands. Nevertheless, I supose that the process of building a GLT file from these lat/lon bands considers lat/lon values as if they were pixel centre coordinates. If this is true, this fact would generate a georeferencing error when images are ge...
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1122 |
22 Jun 2010 04:46 AM |
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2 Replies and 1251 Views
Area measurement 1251 2
Started by Deleted User
Dear List,
After classification, how do I measure area of the classified image in ENVI I tried to use ' Measurement Tool' but it did't work. I would like to get automatic area measurement like Xtools Pro of ArcGIS. Clearly-
Class 1 (water)- 1200 hectares
Class 2 (urban)- 1500 hectares
Class 3 (Agri)- 1700 hectares ....................................n
Please help me.
/Shareful
sharefulgmx.com
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2 |
1251 |
21 Jun 2010 09:21 PM |
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1 Replies and 1121 Views
Cloud Masking 1121 1
Started by Deleted User
I am using Landsat TM data and have cloud cover at diiferent portion of the image. I donot know how to create cloud and their shadow masks and how to apply it.
I want to creatre an image without cloud and shadow......that means cloud area contains no image (blank) in the main image.
Is there any method to subset image with respect to cloud mask......Image - Cloud mask = image with no cloud or shadow.
I am using ENVI 4.5.
Thanks
PK
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1 |
1121 |
21 Jun 2010 09:15 PM |
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1 Replies and 1190 Views
ENVI_GET_DATA 1190 1
Started by Deleted User
I'm trying to read image data into a routine. I'm doing tile processing on these images, so I've been using ENVI_GET_DATA to load each tile. To do this I have to loop through every band of the image to build one tile, which is of dimensions &91tileSize, tileSize, numBands&93. As a result, my code is very slow.
If anyone knows of code that can read in image data what is basically a spatial image subset (not a single band or slice), I would be very grateful for information. Or, if someone ...
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1 |
1190 |
18 Jun 2010 01:09 PM |
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2 Replies and 1024 Views
FLAASH CO2 mixing ratio 1024 2
Started by Deleted User
Can anyone point me towards some references or information explaining why adding 20 ppm to the actual CO2 mixing ratio produces better results in FLAASH The FLAASH documentation simply states "For best results, add 20 ppm to the actual value" and I couldn't find any explanation in the references listed for that section.
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2 |
1024 |
16 Jun 2010 09:31 AM |
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1 Replies and 1055 Views
meteosat MSG datum 1055 1
Started by Deleted User
I would like to know how to add the datum corresponding to the MSG in the datum.txt file. What are the Molodensky x, y, and z shift values in meters from the WGS-84 datum
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1 |
1055 |
15 Jun 2010 10:53 AM |
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1 Replies and 904 Views
getting disconnected while submitting a post in Opera 904 1
Started by Deleted User
Hello,
this is just an info for the forum admin. It has happened to me twice now that I have been disconnected during submitting a post within Opera browser causing errors in the forum (I am editing this in Explorer now)...I'm sorry for the trouble, but I guess it is not entirely my fault.
Cheers
Vaclav
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1 |
904 |
14 Jun 2010 05:59 PM |
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1 Replies and 1085 Views
Don't have FLAASH --- need help writing equ in band math window 1085 1
Started by Deleted User
I do not have FLAASH and need to do an atmospheric correction for a hyperion image using the equation http://edcsns17.cr.usgs.gov/eo1/faq.phpid=21
(sorry, don't know how to paste the equation here).
I have all the values I need, but I am not sure how to write the equation using the band math window.
Can anyone help me out
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1 |
1085 |
12 Jun 2010 04:40 PM |
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0 Replies and 1045 Views
L2 Flags Display in ENVI 1045 0
Started by Deleted User
Hi,
I am working with MODIS Aqua L2 data. I am using EPOC tool to project the MODIS Aqua data in ENVI. Does Any one know how to display the L2 flags in ENVI. I am getting only the bands. I am not getting any information about the L2 flags.
Thanks,
Shiva
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0 |
1045 |
10 Jun 2010 11:24 AM |
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3 Replies and 1033 Views
Image Difference Thresholding 1033 3
Started by Deleted User
Dear Friends,
I have NDVI image of two dates (e.g. 1992 and 2008) and am looking for changes through image differencing and PCA.
I have used band math to create the diffrence image (b1-b2) 100 to find the pixel based diffrence and to convert all negative values to positive. I have created the statistics and got the mean and SD (standard deviation) values along with min and max values.
I want to create change threshold values based on 0.5, 1, 1.5, and 2 SD above and below mean. Could yo...
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3 |
1033 |
10 Jun 2010 02:22 AM |
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3 Replies and 2380 Views
Hyperion destripe 2380 3
Started by Deleted User
Hello list,
I have an inquiry regarding the process of destriping Hyperion lever 1R data in ENVI after import and replacement of anomalous pixels. I wonder if you can actually use the destripe function in ENVI or SPEAR tools for global adjustment of each line to the band mean and variance. I do not really know what is the algorithm behind these functions as I couldn't find any specific info in help. I will appreciate any kind of advice.
Cheers,
Vaclav
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3 |
2380 |
09 Jun 2010 04:47 PM |
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1 Replies and 1216 Views
Sensor Zenith and Azimuth in Flaash 1216 1
Started by Deleted User
Hi!
I´m trying to correct Landsat7 images, and I need help with the "Advanced Settings"->"For non-nadir Looking Instruments" option.
Has Landsat7 a non-nadir looking instrument If yes, Where could I obtain the angles I have searched in MODIS (sensor_zenith and sensor_azimuth) and result values are bizarre!!
Can you help me please
Thank you :)
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1 |
1216 |
09 Jun 2010 04:01 AM |
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2 Replies and 1088 Views
FLAASH LandSat 7 TM and ETM 1088 2
Started by Deleted User
Hi,
I have a series of Landsat 7 imagery and I want to use the FLAASH module for atmospheric correction. Does anyone know of standard parameters for correcting images from arid landscapes The images I'm using cover northern Kenya.
Thanks,
L.
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2 |
1088 |
08 Jun 2010 08:47 AM |
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1 Replies and 1180 Views
wavelength recalibration for hyperion 1180 1
Started by Deleted User
I seem to have some issues with wavelength recalibration on my Hyperion scene. The reflectance image I eventually receive is corrupt as far as I can judge. Spectra don't seem right. I think that is because of some huge wavelength shifts. 3/4 of the channels were shifted by around -15nm.
Determined Wavelength Shift Using NODD Algorithm 1.45548 -14.7804
Determined Shift variance 0.0763074
Wavelength recalibration doesn't correspond to the inp...
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1 |
1180 |
07 Jun 2010 06:48 AM |
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1 Replies and 1160 Views
Heat Island or Surface Temperature 1160 1
Started by Deleted User
Hi,
I have LANDSAT MT and EMT bands images. My question: Is there a way to convert LANDSAT Images or band 6 image to colored map to represent Urban Heat Island or Surface Temperature using ENVI.
Thank you in advance,
Badran
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1 |
1160 |
06 Jun 2010 06:20 PM |
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4 Replies and 1237 Views
Hyperion 1237 4
Started by Deleted User
i was doing hyperion data for atmospheric correction in which flassh module 'hyperion scale text file" missing how to get the file and i need procedure for atmospheric correction of hyperion 1GST correction, in which result are not coming using Flassh module
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4 |
1237 |
04 Jun 2010 05:39 AM |
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0 Replies and 1213 Views
MODIS Aqua L2 batch processing 1213 0
Started by Deleted User
Hi,
I am working with MODIS Aqua L2 data. I am using the ENVI Plugin for Ocean Color (EPOC) tool to process the images in ENVI software to assign the projection. It is taking more than 1 hour to assign the projection for one image. MODIS Aqua L2 image contains different bands. I want to consider only one band (chlor_a) . Is there any way to process only one band instead of all bands in one image If yes we can save a lot of time and memory in the computer. And can anyone please give me some ...
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1213 |
03 Jun 2010 08:36 AM |
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4 Replies and 1208 Views
how to create a txt file for class statistics for each ROI 1208 4
Started by Deleted User
Hello,
I have created about 300 ROI. I would like to calculate the class statistics for each one of these ROI. When I do it through the Class statistic Tool I get one file with just one class distribution for ALL ROI put togeather. Is there a way to separate each class statistic for each of the 300 ROI
Thank you
Colibri
p.d I am using ENVI 4.5
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4 |
1208 |
01 Jun 2010 01:32 PM |
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1 Replies and 1355 Views
generate random points with certain restrictions 1355 1
Started by Deleted User
Hello,
So I am sort of stuck on trying to generate random points with certain restrictions in ENVI 4.5.
I have successfully generated 60 random points with the “Post Classification- Generate Random Sample” for an image classification using the vegetation delineation tool. The vegetation delineation tool generated four vegetation densities using NDVI: 1) noveg, 2) sparseveg, 3) moderateveg and 4) denseveg. I have used both stratified random sampling as well as random.
However what I r...
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1 |
1355 |
01 Jun 2010 10:12 AM |