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Re: Map pixel areas [message #88567 is a reply to message #88566]

Tue, 13 May 2014 07:42

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

kimberly.hyde@noaa.gov writes:

> The reason I am trying to figure out the pixel areas is I need to know the difference between a the "projected" area of a specified region of interest and the "true" area of the ROI. I have several dozen maps that have been created using MAP_SET and are used to remap satellite derived data. I have never used MAP_PROJ_INIT and will look into it more, but if I can figure out how to do this with the maps I already have that would be great.
>
> The main thing I am trying to do is determine the areal production within a subsetted area of the map. Because we are using the sum of the pixels in the ROI, I need to know both the "projected" size and the "actual" size (which I already know), to get an accurate areal estimate. Again, I am not sure I am explaining this very well, but I do appreciate any suggestions.

Why would you be concerned with the "projected" area if you know the
actual area? Isn't one a visualization, a figment of the imagination,
and the other a real, actual, physically meaningful quantity?

In any case, I really don't have a clue how this could be done with
Map_Set. Sorry. :-(

Cheers,

David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thue. ("Perhaps thou speakest truth.")

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[Message index]

		Map pixel areas By: khyde on Fri, 09 May 2014 09:12
		Re: Map pixel areas By: David Fanning on Fri, 09 May 2014 09:44
		Re: Map pixel areas By: khyde on Tue, 13 May 2014 07:14
		Re: Map pixel areas By: David Fanning on Tue, 13 May 2014 07:42

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