[Proj] ECEF

[Clifford J Mugnier]

Noel,

Your conclusion is correct with regard to PROJ4; it does not support datum
shifts of any kind.  Mr. Evenden is of the same philosophy as John P.
Snyder was in regard to that topic.

Regards,

Cliff

Clifford J. Mugnier
Chief of Geodesy and
Associate Director,
CENTER FOR GEOINFORMATICS
Department of Civil Engineering
CEBA 3223A
LOUISIANA STATE UNIVERSITY
Baton Rouge, LA  70803
Voice and Facsimile:  (225) 578-8536 [Academic]
Voice and Facsimile:  (225) 578-4474 [Research]
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Quick first question from a newcomer exploring the  capabilities of Proj.4
before attempting to compile the code.

I've read the documentation plus recent threads on  this list serve that
discuss datum shifts (of the 7-parameter variety), which,  apparently,
Proj.4 does not support.  My question is whether  Proj.4 supports
Earth-Centered Earth-Fixed (ECEF) geocentric Cartesian  coordinates or not
(i.e, lat/lon/hgt => ECEF X/Y/Z).  Seems it would be  simple to build that
functionality into the Proj.4 code, but I gather that the  documentation's
references to "cartesian coordinates" means Eastings/Northings  in
projected space, and not ECEF.  Non-support for geocentric datum  shifting
seems to support this tentative conclusion.  Can someone  confirm for me?

Thanks, Noel Zinn