Re: Radar3DCoordinateSystem

Hi Kevin-

Kevin Manross wrote:
Thank you for your sample code. I got it to work after seeing that - though what is *really* frustrating is I now cannot duplicate the error I was having. Arrggh! Oh well, It works and I should let it go. ;-)

I hate when that happens! ;-)

For those who use the Radar3DCoordinateSystem:

I did a little comparring between an in-house AzRanElev-to-LatLonAlt algorithm and the Radar3DCoordinateSystem toReference() method and found that the latter does not account for the INDEX OF REFRACTION of the Earth's atmosphere. For "standard atmospheric conditions" the index of refraction is 4/3 * the Earth's Radius. This resulted in ~ 200 m difference at a range of 100 km and a ~300 m at a range of 400 km using an elevation angle of 0.5 degrees.

If anyone has any questions about this, I'd be happy to try to answer them.

Maybe we could modify Radar3DCS to take this into account.
It might be as simple as adding a new constructor that would take
a boolean flag to indicate whether this should be done or not
(with default as is for legacy apps).

I'll contact you off-line about this.

Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
"There's someone in my head, but it's not me"    Roger Waters
*************************************************************