| Re: AVHRR Image Mapping Problem [message #51986 is a reply to message #51852] |
Fri, 15 December 2006 12:07   |
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Matt[1]
Messages: 23
Registered: December 2006
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Junior Member |
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Not sure. I use the IDL+ENVI package, which may or may not be able to
handle it. I say this because I have never tried doing anything with
vector data but the most basic operarions in ENVI. Seing that it's an
image analysis program, I would be suprised if it's vector capabilites
are very robust. Conversely, if you had ArcGIS you could probalby
convert your vector data to your required format in 5 minutes.
You could work the problem from the opposite angle, meaning that you
could try and adjust the image to fit the projection of the vector
data. Can you warp the image to the projection of your country outline
(is it geographic)? This is done in envi using
envi_convert_projection_coordinates, which converts coordinates from
one projection to another. I don't know if this is available as another
function in stand-alone IDL.
Also, keep in mind that geographic coordinates are no good if you are
trying to measure areas or distances. So converting to geographic may
not be useful if you are trying to quantify rather than visualize.
Matt
On Dec 15, 2:33 pm, David Fanning <n...@dfanning.com> wrote:
> Matt writes:
>> Raster data in Albers centered on Africa
>> Vector data for the world in some other projection, probably centered
>> on the prime meridian
>
>> If you get all this data to a single format (extent of African
>> continent only - not the world, both datasets in Albers with same std
>> parallels), this this could resolve the misalignment...Well, you have identified my problem in a nutshell! :-)
>
> The real question for me and my client is this: can it
> be done in IDL? Any thoughts on that?
>
> Cheers,
>
> David
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming:http://www.dfanning.com/
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
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