Dear Steve and Mark
In view of the need for a reference level, it's part of the definition of the
standard names that have units in decibels.
Cheers
Jonathan
----- Forwarded message from Steven Emmerson <emmerson at ucar.edu> -----
> Date: Wed, 29 May 2013 09:25:59 -0600
> From: Steven Emmerson <emmerson at ucar.edu>
> To: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] dB decibel units
>
> Mark,
>
> Logarithmic units need a reference level in order to support numerical
> conversions; "dB" doesn't have one. A decibel unit with a one milliwatt
> reference level would be "0.1 lg(re 1 mW)".
>
> Regards,
> Steven Emmerson
> Software Developer
> Unidata Program Center
> University Corporation for Atmospheric Research
>
>
> On Wed, May 29, 2013 at 4:31 AM, Hedley, Mark
> <mark.hedley at metoffice.gov.uk>wrote:
>
> > Hello CF
> >
> > A few standard names:
> >
> > sound_intensity_level_*
> > sound_pressure_level_*
> >
> > have a stated canonical units of dB. I think valid units in CF are
> > defined by udunits2.
> >
> > My install of udunits (udunits2-2.1.24) does not recognise dB as a valid
> > units string.
> >
> > Is this an issue for the CF standard names maintainers or for the udunits
> > maintainers?
> >
> > thank you
> > mark
> >
> >
> > _______________________________________________
> > CF-metadata mailing list
> > CF-metadata at cgd.ucar.edu
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >
> >
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
----- End forwarded message -----
Received on Wed May 29 2013 - 09:34:10 BST
