Hi all (esp John),
If a dataset uses a projected coordinate system (e.g. rotated pole or
polar stereographic), then the CF conventions state that the dataset
must specify the projection and its parameters (e.g. the location of
the new pole) *and* provide two-dimensional axes containing the
latitude and longitude of each grid point
(http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#id2985006).
These 2D axes are technically redundant as they could be calculated
from the projection parameters and the coordinates in the projected
system, but are included for convenience.
Does Java-NetCDF recognise such datasets as having 1D horizontal
coordinate axes (in the projected system) or 2D horizontal coordinate
axes (based on the grid mapping)? I would have expected the former
but are seeing behaviour consistent with the latter, using the
GridCoordSys object. We've seen this behaviour with both polar
stereographic (TOPAZ) and rotated-pole data.
If the former is indeed the expected behaviour then we might have a
bug in the metadata. (In which case, Adit, could you send John the
ncdump output if he requests it?)
Cheers, Jon
--
Dr Jon Blower
Technical Director, Reading e-Science Centre
Environmental Systems Science Centre
University of Reading
Harry Pitt Building, 3 Earley Gate
Reading RG6 6AL. UK
Tel: +44 (0)118 378 5213
Fax: +44 (0)118 378 6413
j.d.blower@xxxxxxxxxxxxx
http://www.nerc-essc.ac.uk/People/Staff/Blower_J.htm
