Re: Lat/Lon to Polar: Revisited



Bill Hibbard wrote:

But one useful piece of information is "(516,0)". Note that
516 is about half of LengthX = 1033, so the offending grid
box is at the haflway point along X. In fact, the offending
grid box from X=516 to X=517 exactly straddles 1033/2.

If X is your azimuth coordinate, is there an error in
computing angles halfway around the circle? One possibility
is that angles increase from X=0 to X=516, then there is a
decrease from X=516 to X=517, then they increase again.
Something like that. Or if X is your radius coordinate, is
there a similar error in computing radius halfway out, at
X=516?

Hi Bill,

Yes, in my original terrain file, the domain is a LinearLatLon set with X -> Lon, and Y -> Lat. If you put the radar at the center of that domain, and my X (Lon) increases for X = 0->1033, then my azimuth will decrease to 0 (at the midpoint of X [516]) and then increase.

Perhaps Don's suggestion of using a CachingCoordinateSystem to wrap my Radar2DCS is the best way to go, as opposed to changing my data?

Thanks for the help!

-kevin.



--
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Kevin L. Manross        [KD5MYD] <><          (405)-366-0557
CIMMS Research Associate               kevin.manross@xxxxxxxx
[NSSL-WRDD/SWATN]           http://www.cimms.ou.edu/~kmanross

"My opinions are my own and not representative of CIMMS, NSSL,
NOAA or any affiliates"
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