John and others interested, I was part of the initial request that dated back to 2014. Here’s the original GitHub ticket (still open) capturing the correspondence with the UDUNITS team: https://github.com/Unidata/UDUNITS-2/issues/33
I was corresponding with “mhidas” and “semmerson”, so I don’t know if these people are still on this project, as no further correspondence has taken place since July 2015. I made another attempt last year to bring some life to this request, but to no avail. There was another user inquiring about representing dB as a unit, but that ticket has since closed and it’s not clear to me from the thread whether there was a positive resolution. Here’s that link: https://github.com/r-quantities/units/issues/176 Others on here are more than welcome to pursue this further. Cheers, David From: CF-metadata <cf-metadata-boun...@cgd.ucar.edu> on behalf of John Graybeal <jbgrayb...@mindspring.com> Date: Sunday, November 11, 2018 at 9:33 PM To: Jonathan Gregory <j.m.greg...@reading.ac.uk> Cc: CF Metadata List <cf-metadata@cgd.ucar.edu> Subject: Re: [CF-metadata] Decibel units in CF standard names Just as an aside (or maybe not), the udunits support list has been asked before to include dB, and I understood that they had (I think I actually saw it, but can’t find written confirmation). So it wouldn’t surprise me if the library included dB. In case it’s useful I pasted in a bit of the old thread below. john --------------------------------------- John Graybeal jbgrayb...@mindspring.com<mailto:jbgrayb...@mindspring.com> On Nov 4, 2018, at 09:03, Jonathan Gregory <j.m.greg...@reading.ac.uk<mailto:j.m.greg...@reading.ac.uk>> wrote: Dear Martin Your points are good ones and have been raised before. More than once we have talked about maintaining a CF version of the udunits definition to include dB and sverdrup, or ask udunits to add them (if they're not there). dB is a dimen- sionless unit, equivalent to 1. I suggest that dBZ should be changed to dB, as I don't think we ought to have several of them. I believe that the default reference levels are mostly conventional and stated in the definitions of the standard name, as you say. They can be overridden by supplying a size-one or scalar coordinate variable. You have previously suggested an xml table to contain more information about the definition of standard names, haven't you? It seems to me that an arrangement like that would be the right place to store the default reference levels and scale factor in a machine-readable way. Best wishes Jonathan ----- Forwarded message from Martin Juckes - UKRI STFC <martin.juc...@stfc.ac.uk<mailto:martin.juc...@stfc.ac.uk>> —— Begin forwarded message: From: "Moroni, David F (398M)" <david.f.mor...@jpl.nasa.gov<mailto:david.f.mor...@jpl.nasa.gov>> Subject: Re: [CF-metadata] [cf-satellite] normalized_radar_backscatter_coefficient Date: August 8, 2014 at 3:10:50 PM PDT To: John Graybeal <john.grayb...@marinexplore.com<mailto:john.grayb...@marinexplore.com>>, "rho...@excaliburlabs.com<mailto:rho...@excaliburlabs.com>" <rho...@excaliburlabs.com<mailto:rho...@excaliburlabs.com>> Cc: "Weiss, Barry H (398B)" <barry.h.we...@jpl.nasa.gov<mailto:barry.h.we...@jpl.nasa.gov>>, Jonathan Gregory <j.m.greg...@reading.ac.uk<mailto:j.m.greg...@reading.ac.uk>>, "cf-satell...@unidata.ucar.edu<mailto:cf-satell...@unidata.ucar.edu>" <cf-satell...@unidata.ucar.edu<mailto:cf-satell...@unidata.ucar.edu>>, CF Metadata List <cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>> Hi John, Thanks for providing the email link. I've already emailed Unidata and they are processing my request to include dB within UDUNITS. Cheers, David From: John Graybeal <john.grayb...@marinexplore.com<mailto:john.grayb...@marinexplore.com>> Date: Friday, August 8, 2014 10:57 AM To: "rho...@excaliburlabs.com<mailto:rho...@excaliburlabs.com>" <rho...@excaliburlabs.com<mailto:rho...@excaliburlabs.com>> Cc: "Weiss, Barry H (398B)" <barry.h.we...@jpl.nasa.gov<mailto:barry.h.we...@jpl.nasa.gov>>, David F Moroni <david.f.mor...@jpl.nasa.gov<mailto:david.f.mor...@jpl.nasa.gov>>, Jonathan Gregory <j.m.greg...@reading.ac.uk<mailto:j.m.greg...@reading.ac.uk>>, "cf-satell...@unidata.ucar.edu<mailto:cf-satell...@unidata.ucar.edu>" <cf-satell...@unidata.ucar.edu<mailto:cf-satell...@unidata.ucar.edu>>, CF Metadata List <cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>> Subject: Re: [CF-metadata] [cf-satellite] normalized_radar_backscatter_coefficient This request has now been made by me of UDUNITS on general principle, but I think individuals could also express their desire as a way to move the ball forward. John On Aug 7, 2014, at 07:57, rho...@excaliburlabs.com<mailto:rho...@excaliburlabs.com> wrote: Dear Barry and David: For udunits support, send an email to support-udun...@unidata.ucar.edu<mailto:support-udun...@unidata.ucar.edu>. very respectfully, randy ________________________________ From: "Weiss, Barry H (398B)" <barry.h.we...@jpl.nasa.gov<mailto:barry.h.we...@jpl.nasa.gov>> Sent: Thursday, August 07, 2014 10:06 AM To: "Moroni, David F (398M)" <david.f.mor...@jpl.nasa.gov<mailto:david.f.mor...@jpl.nasa.gov>>, "Jonathan Gregory" <j.m.greg...@reading.ac.uk<mailto:j.m.greg...@reading.ac.uk>> Cc: "Niedfeldt, John C (398M-Affiliate)" <john.c.niedfe...@jpl.nasa.gov<mailto:john.c.niedfe...@jpl.nasa.gov>>, "CF Metadata List" <cf-metadata@cgd.ucar.edu<mailto:cf-metadata@cgd.ucar.edu>>, "John Graybeal" <john.grayb...@marinexplore.com<mailto:john.grayb...@marinexplore.com>>, "cf-satell...@unidata.ucar.edu<mailto:cf-satell...@unidata.ucar.edu>" <cf-satell...@unidata.ucar.edu<mailto:cf-satell...@unidata.ucar.edu>> Subject: Re: [cf-satellite] [CF-metadata] normalized_radar_backscatter_coefficient Jonathan, As the data product engineer for the SMAP project, I second David's request. We are attempting to employ CF metadata in our products. This is not a challenge at level 2 and above where our products provide geophysical measure, but is a challenge at level 1, where our products provide instrument measurements. Please consider inclusion of dB units. That should include dB based on unit less measure, as well as dB relative to watts and volts. Thanks and Regards, Barry On 8/6/14 7:49 PM, "Moroni, David F (398M)" <david.f.mor...@jpl.nasa.gov<mailto:david.f.mor...@jpl.nasa.gov>> wrote: >Hi Jonathan, > >Just as follow up from my last email, I noticed an online email exchange >where you had responded to a request to use units of dB (decibels) even >though it is not currently in the udunits database: >http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2013/056572.html > >We also agree it would be wise to include dB in the udunits database, and >we will be applying these units for our scatterometer datasets. > >We hope to see this incorporated in the near future. > >Thanks again for your considerations. > >Cheers, >David >
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