[GRASS-user] value differences between landsat images
Jonathan Greenberg
greenberg at ucdavis.edu
Wed May 21 02:29:15 EDT 2008
Use the overlap region to pick PIFs (pseudoinvariant features), run a
regression between the band values of the PIFs between one image and the
other, apply the regression coefficients, and voila! If you just assume
the entire overlap region is fine (no clouds or changed pixels), and
they are orthorectified to one another, then you can extract the entire
overlap region and run the regression on all those pixels.
The other way is to calculate the mean and stdev of the band values, and
adjust them that way, but I always felt the regression approach is a
little more straightforward.
There's a few automated algorithms out there to do this -- anyone want
to write some code for it :) ?
http://scholar.google.com/scholar?sourceid=Mozilla-search&q=radiometric+normalization+%22remote+sensing%22
Canty's got some IDL code to do radiometric normalization that can be
downloaded -- IDL's an easy language to read, so the code should be easy
to port to something GRASS could use:
http://www.crcpress.com/e_products/downloads/download.asp?cat_no=7251
--j
Michael Barton wrote:
>
>
> On 5/20/08 8:24 PM, "grass-user-request at lists.osgeo.org"
> <grass-user-request at lists.osgeo.org> wrote:
>
>> Date: Tue, 20 May 2008 11:44:51 -0700
>> From: Jonathan Greenberg <greenberg at ucdavis.edu>
>> Subject: Re: [GRASS-user] value differences between landsat images
>> To: Juan Manuel Barreneche <jumanbar at gmail.com>
>> Cc: grass-user at lists.osgeo.org
>> Message-ID: <48331C23.8070705 at ucdavis.edu>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> Juan:
>>
>>>
>> It just means your images aren't radiometrically normalized to one
>> another. If you correctly normalize them you won't see a line in the
>> mosaic.
>
> I'll bite. How do you radiometrically normalize adjacent Landsat images. I'd
> love to get rid of the lines.
>
> Michael
>
>>>> Hamish
>>>>
>>> JM
>>> -------------------------------------------------------
>
> __________________________________________
> Michael Barton, Professor of Anthropology
> Director of Graduate Studies
> School of Human Evolution & Social Change
> Center for Social Dynamics & Complexity
> Arizona State University
>
> phone: 480-965-6213
> fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
>
>
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--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room 250N
Davis, CA 95616
Cell: 415-794-5043
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