[aprssig] future problems with NWS radar images?
steve at dimse.com
Mon Mar 28 23:02:41 CST 2005
On Mar 28, 2005, at 5:59 PM, AE5PL Lists wrote:
> this does make some difference in plotting, especially in the outer
> of the coverage area.
I did a very quick overlay of the two maps
I think with a little care in the scale and rotation of the two images,
one could come up with a better fit, but even this is only a few pixels
error over most of the map. The big concern here is the tilt of the
map...the current images must be rotated quite a bit to align with the
new one. As presently implemented, geo files cannot handle this
rotation, it would take a third point to define the rotation. There is
no reason this cannot be implemented should the NWS switch to this new
style, but it would mean not only all programs using geo files would
need to be updated. If I read Pete's explanation correctly, it sounds
like the present radar images are the ones which are not the orthogonal
projection geo files expect, so perhaps new geo files with the new
image projection, even without rotation, would be more accurate. Do I
have that right Pete?
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