objective analysis & topography

[Keith Lindsay <klindsay@xxxxxxxxxxxx>]

Greetings,

I am contouring scattered data from a vertical cross section of the ocean.
The basic approach that I can come up with is to first transfer the data
to a regular grid with the GO tool objective and then to use contour on
the result.

However, I do not think that this approach is topographically aware in the
following sense. From my reading of the Ferret User's Guide, the objective
analysis is doing some kind of splining/Laplacian interpolation. So a
point from the scattered data set affects grid points which are "near" it.  
This effect is not aware of bottom topography and for instance could occur
through an ocean ridge. I would like to avoid this.

Is my understanding of how objective works correct? If so, is there a way
to incorporate topography into an objective analysis or is there another
overall approach to producing a contour plot of scattered data?

I think the central question is "How can I perform an objective analysis
on an irregular geometry?"

***********************************************************************
Keith Lindsay                              phone: 303-497-1722
Climate and Global Dynamics                fax:   303-497-1700
National Center for Atmospheric Research   email: klindsay@cgd.ucar.edu
P.O. Box 3000
Boulder, CO  80307-3000