Hi All, As a new comer to the world of metorological/oceanographic datasets, I am currently reading up on a number of subject matters including the use of the UDUNITS package and the use of version 1 or 2 for CF conformance. As a result of a URL kindly provided by Mike Grant, Plymouth Marine Laboratory I came across a posting by Andrew Clegg in March 2010: >I'm running into some problems regarding units in CF-compliant files. Up >until now I've been using udunits 1 to check units, but I recently tried >the CF checker which uses udunits2. There are some unit strings which >are valid in one but not the other. In particular, I am dealing with >milligrams per cubic meter. In udunits1, I used 'ukg m^-3', which >udunits2 rejects as invalid. udunits2 accepts 'mg m^-3' (which is much >better!), but udunits1 interprets this as to do with gravity. Because of >this, I can't include a unit string which is generally compatible with > udunits...
My query relates to the specifications quoted for dealing with milligrams per cubic meter values, i.e. 'ukg m^-3' for version 1, and 'mg m^-3' for version 2. When I enter either value, or indeed 'mg/m3', into my installed version 1 (v1.12.11) of 'udunits' it reports the definition as '1e-06 kilogram metre-3' implying a unit value of '0.000001 kg/m3' - and what I would expect, i.e. kilograms per cubic metre. However, when I enter the same values into my installed version 2 (v2.1.23) of 'udunits2' it reports the definition as '1e-06 m-3 kg' implying a unit value of '0.000001 m3/kg' - and not what I would expect, i.e. cubic metres per kilogram. Has anyone else noted this, or can somebody correct my interpretation of the meaning of 'm-3 kg'. Kind regards, Glenn Comiskey Data System Administrator Fugro Global Environment & Ocean Sciences Fugro House, Hithercroft Road Wallingford, Oxfordshire OX10 9RB, UK Registration No: 2985431 / VAT No: GB 655475606 Tel: +44 (0) 1491 820500 (Switchboard) / Tel: +44 (0) 1491 820559 (Direct) / Fax: +44 (0) 1491 820599 E-mail: [email protected] <mailto:[email protected][email protected]> / Website: www.geos.com <http://www.geos.com/> Please note: * The information contained in this message is privileged and confidential and intended only for the use of the addresses. If you are not the intended recipient you should not read, copy, distribute or otherwise use the information; * Fugro Global Environment & Ocean Sciences accepts no responsibility for loss or damage of any kind arising from the use of this message; * If you have received this message in error, please note the sender immediately and delete the message. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
