Hi John,
I think this was an issue worth raising. There certainly seems to be the potential for ambiguity.
I just searched the CF archive to find any approved examples of either physical_quantity_by_instrument or physical_state_of_instrument.
I had thought there were cases of the former for specific satellite instruments, but I couldn't find one. Perhaps I missed it, or it was discussed but not approved yet.
I did find one example of the latter:
temperature_of_sensor_for_oxygen_in_sea_water
If we followed this convention, then the temperature of the antenna (if it were required) would presumably be something
like:
temperature_of_antenna,
I am not an expert in antennas, but as I understand it, antenna temperature is a similar type of quantity as brightness temperature. Am I correct? If so, antenna_temperature would seem the obvious choice for CF (following brightness_temperature which is already part of CF), and it would avoid ambiguity because of the example above.
Best wishes,
Philip
-----------------------------------------------------------------------
Dr Philip Cameron-Smith, pjc at llnl.gov, Lawrence Livermore National Lab.
-----------------------------------------------------------------------
> -----Original Message-----
> From: cf-metadata-bounces at cgd.ucar.edu [mailto:cf-metadata-
> bounces at cgd.ucar.edu] On Behalf Of John Graybeal
> Sent: Monday, May 02, 2011 2:34 PM
> To: Ken Roberts
> Cc: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] New CF Standard Name (antenna_temperature)
>
> You're right, I can't argue that 'antenna temperature' is widely used
> in another way. Though by limiting your field to remote sensing, you
> are excluding some heavy in situ users of CF, the ocean communities.
>
> In ocean systems I've seen many a 'component_temperature' pattern, from
> can_temperature to processor_temperature to panel_temperature (none in
> CF, mind you -- it's not a concept that is easily interoperable). I
> can't swear from personal experience I've ever seen an
> antenna_temperature; maybe no one *ever* cares about that.
>
> So I'll only toss out there that 'antenna noise temperature' has no
> possible ambiguity with antenna physical temperature, and seems to be
> the Wikipedia term of choice (even if 'antenna temperature' wins the
> Google fight by about 5 to 1 :->) -- just in case you like 'antenna
> noise temperature' equally well. Of course, Wikipedia defines that as
> "the temperature of a hypothetical resistor at the input of an ideal
> noise-free receiver that would generate the same output noise power per
> unit bandwidth as that at the antenna output at a specified frequency"
> -- it may be that you have in mind a different concept.
>
> I will stop rambling now on this topic, so if no one else expresses
> concern you may consider me agreeable.
>
> john
>
> On May 2, 2011, at 06:11, Ken Roberts wrote:
>
> > John,
> >
> > We could not find any well-cited or commonly known circumstances in a
> > related field (to remote sensing) where the antenna temperature can
> mean
> > "the temperature of the antenna itself." Maybe you could suggest a
> case
> > where antenna temperature has such a meaning in terms of measurements
> so
> > we can identify a potential conflict. As far as we can tell, antenna
> > temperature is used to "relate the power emitted by [a] source to an
> > interesting physical property of that source."
> > [http://map.gsfc.nasa.gov/site/glossary.html]
> >
> > Regards,
> > Ken
> >
> > On 4/27/2011 12:30 PM, John Graybeal wrote:
> >> Sorry, a doofus question here.
> >>
> >> Isn't the antenna temperature affected to some degree by the
> temperature of the environment it is in? I am thinking of temperature
> in the common vernacular, sorry if that is the wrong context. But I
> see a potential conflict with those measurements of antenna temperature
> that are taken strictly to learn what the temperature of the antenna
> is, and having nothing to do with the power per unit bandwidth received
> from a source.
> >>
> >> John
> >>
> >> On Apr 27, 2011, at 08:51, Ken Roberts wrote:
> >>
> >>> All,
> >>>
> >>> If there are no objections or requested changes, can it be
> confirmed
> >>> that the following proposed name will be added to the next version
> of
> >>> the CF Standard Name Table?
> >>>
> >>> Standard Name: antenna_temperature
> >>> Definition: A measure of the power per unit bandwidth received from
> a
> >>> source by an antenna
> >>> Units: Kelvin
> >>>
> >>> Thanks,
> >>> Ken
> >>>
> >>> On 4/6/2011 12:48 PM, Ken Roberts wrote:
> >>>> All,
> >>>>
> >>>> The National Climatic Data Center (NCDC) has a Special Sensor
> >>>> Microwave/Imager (SSM/I) product currently being developed for the
> >>>> Climate Data Record (CDR) program. The dataset contains variables
> for
> >>>> brightness temperature and corresponding antenna temperature
> values.
> >>>> Given that there does not appear to be a fitting CF standard name
> for
> >>>> antenna temperature, we would like to propose a new name,
> >>>> antenna_temperature, defined as a measure of the power per unit
> >>>> bandwidth received from a source by an antenna (units are Kelvin).
> >>>>
> >>>> Regards,
> >>>> Ken
> >>>>
> >>> --
> >>> Ken P. Roberts
> >>> Programmer Analyst, STG, Inc., Government Contractor
> >>> Remote Sensing & Applications Division
> >>> National Climatic Data Center
> >>> 151 Patton Ave.
> >>> Asheville, NC 28801-5001
> >>> Phone: (828) 271-4083
> >>> Fax: (828) 271-4328
> >>> Ken.Roberts at noaa.gov
> >>>
> >>> _______________________________________________
> >>> CF-metadata mailing list
> >>> CF-metadata at cgd.ucar.edu
> >>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >>
> >>
> >> John Graybeal <mailto:jgraybeal at ucsd.edu>
> >> phone: 858-534-2162
> >> Product Manager
> >> Ocean Observatories Initiative Cyberinfrastructure Project:
> http://ci.oceanobservatories.org
> >> Marine Metadata Interoperability Project: http://marinemetadata.org
> >>
> >
> >
> > --
> > Ken P. Roberts
> > Programmer Analyst, STG, Inc., Government Contractor
> > Remote Sensing & Applications Division
> > National Climatic Data Center
> > 151 Patton Ave.
> > Asheville, NC 28801-5001
> > Phone: (828) 271-4083
> > Fax: (828) 271-4328
> > Ken.Roberts at noaa.gov
> >
> > _______________________________________________
> > CF-metadata mailing list
> > CF-metadata at cgd.ucar.edu
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
>
>
> John Graybeal <mailto:jgraybeal at ucsd.edu>
> phone: 858-534-2162
> Product Manager
> Ocean Observatories Initiative Cyberinfrastructure Project:
> http://ci.oceanobservatories.org
> Marine Metadata Interoperability Project: http://marinemetadata.org
>
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Received on Mon May 02 2011 - 20:13:16 BST
