id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
159	Geodesy routine correctness	Huw Lewis	Ian Culverwell	"From ROPP-2 beta test report (section 3 ""Correctness""):


{{{
The reviewer has identified several instances in the geodesy subpackage where improvements could be possible:

• Geometric vs geopotential transformations: Several details were 
found not to be of sufficient accuracy. The expressions used 
conform to estimations that are standard in meteorological 
contexts. However, they are less accurate than the GPSRO technology
is, and thus will be-come the limiting factor for the data. The 
reviewer considers this as “correct” in the sense that conforms to 
standard practice. However this should be addressed in future ROPP 
versions.

•Earth radius: The quantity estimated (Somigliana) is not the 
radius of curvature. It is not an accurate estimation of the radius 
of curvature (which depends not only on latitude, but also on the
azimuth). It is not more accurate for the estimation of the 
geopotential than a fixed average radius. Instead, it is much more 
computationally expensive. The error is compara-tively small in the
way and context that this quantity is used in this release. However,
it could lead to very substantial errors if this quantity was used 
in other contexts within GPSRO applications where the Earth radius 
is also needed. This should be addressed as fu-ture releases of 
ROPP may very likely require this quantity for other purposes.


}}}

"	enhancement	closed	normal	6.0	ropp_utils	3.0	fixed	geodesy	Ian Culverwell