| Re: Land/Water Database [message #50724] |
Wed, 11 October 2006 16:28 |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Andrew Cool writes:
> The GSHHS shoreline database includes lakes and islands down to
> itty-bitty size, and could satisfy almost all needs using a graphical
> method.
Well, that's what I thought, and recommended. I'll have
to wait and see what they think.
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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| Re: Land/Water Database [message #50725 is a reply to message #50724] |
Wed, 11 October 2006 16:22  |
Andrew Cool
Messages: 219
Registered: January 1996
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Senior Member |
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David Fanning wrote:
> Folks,
>
> Does anyone know of a database where I can get fairly
> high-resolution land/water data for a particular lat/lon?
> In other words, I want to make a water mask for a particular
> image. If I know the lat/lon of each pixel, do you know
> of a way I can look in a database to see if that pixel
> is over land or water (or, presumably) both?
>
> I can think of graphical ways to do this, but
> supposedly this is not of sufficient accuracy for the
> person asking the question.
David,
You don't say just how accurate you need to be!
GTOPO30 gives you 1km by 1km resolution. Takes 5 CD's to cover the
globe.
The Shuttle Radar Topography Mission (SRTM) DEM gives you much higher
resolution, but I think only covers +/- 40 (50?) degrees of latitude.
Takes 13 DVD's
to cover that central "belly" portion of the globe. Extra hires data
available for USA.
The GSHHS shoreline database includes lakes and islands down to
itty-bitty size, and could satisfy almost all needs using a graphical
method.
Cheers,
Andrew C.
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