Spheroidal vs. spherical coordinates
Added by Christian Steger almost 4 years ago
Hi
I'm using CDO for remapping and I'm confused about how CDO handles geographic coordinates (sphere vs. on elllipsoid). This paper gives a nice overview about the issue:
https://journals.ametsoc.org/view/journals/mwre/141/6/mwr-d-12-00351.1.xml
I'm e.g. using CDO to remap data from a Lambert Conformal Conic projection to a latitude/longitude grid. This requires a PROJ string, which also provides information on the reference system of the input data (ellps=WGS84 vs. ellps=sphere). Let's say my input data is defined on a ellipsoid (ellps=WGS84) and I remap it with CDO remapbil to a latitude/longitude grid. Are the obtained latitude/longitude coordinates now valid for an ellipsoid or a sphere? I guess internally in CDO, all coordinates are assumed to be spherical coordinates - right? I.e. a coordinate system rotation (due to a shifted pole) is for instance performed with spherical coordinates.
To conclude the confusing topic: does CDO assume that spheroidal and spherical are identical (as discussed in the above paper)?
Thanks a lot for your help!
Replies (1)
RE: Spheroidal vs. spherical coordinates - Added by Uwe Schulzweida almost 4 years ago
Hi Christian,
yes, the remapping in CDO assumes that spheroidal and spherical are identical!
Cheers,
Uwe