[aprssig] future problems with NWS radar images?
AE5PL Lists
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Mon Mar 28 17:59:37 EST 2005
The current radar gifs are done using a stereographic projection
centered on the radar site with an Earth radius of 6371.2 km. This is
done this way, I would guess, because the dots can be charted using
simple polar coordinates instead of doing lat/lon translations. Yes,
this does make some difference in plotting, especially in the outer half
of the coverage area.
As to their new graphics, I have not worked with them yet to get the
full information on how they are being projected into the image.
73,
Pete Loveall AE5PL
mailto:pete at ae5pl.net
> -----Original Message-----
> From: Tyler Allison
> Posted At: Monday, March 28, 2005 4:31 PM
> Subject: Re: [aprssig] future problems with NWS radar images?
>
> > Does anyone else have any information as to where the NWS
> is going here?
>
> The original radar data, as provided to the research
> community via the Unidata IDD Cooporative, is supposedly in
> Lambert Conformal. Im not up on my projections but maybe
> that's the "spherical" projection they are talking about?
>
> Instead of using the GIF images why not grab the radar data
> raw (via FTP) and convert to image format yourself using
> Gempak? That way you can control the projection.
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