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[UDUNITS #VZX-973749]: Re: dB

David,

Sorry for taking so long to respond. I'm the UDUNITS developer (among other 
things) and I've been sick at home since the weekend and it's hard to think.

What you ask is doable and needs to be done. It would require the creation of a 
new type of unit that corresponds to a logarithmic unit with no reference 
level. It would only be possible to convert values in such a unit to values in 
other, unreferenced logarithmic units (e.g.: "dB" to "dN"); consequently, it 
could only be used for *changes* in physical quantities. The creation of such a 
unit should be straightforward though non-trivial.

I don't suppose you guys have any money? Just kidding. (Not really. :-).

Would you do me a favor and add it to the list of issues on the UDUNITS GitHub 
site <https://github.com/Unidata/UDUNITS-2/issues> so I don't forget.

> Dear Unidata,
> 
> As indicated by multiple requests included in the email thread below,
> please consider including dB (decibels) as a standard unit within the
> udunits database.
> 
> I will be more than happy to give you more details on the definition and
> application of these units once you're ready to proceed with the inclusion.
> 
> Thank you for your consideration.
> 
> Cheers,
> David
> 
> 
> ==================================================
> David Moroni
> Ocean Wind and Scatterometry Data Engineer
> Physical Oceanography Distributed Active Archive Center
> Jet Propulsion Laboratory
> 4800 Oak Grove Dr
> M/S 158-242
> Pasadena, CA 91109
> Phone:  818.354.2038
> Fax:  818.353.2718
> ==================================================
> 
> 
> 
> 
> 
> On 8/7/14 11:00 AM, "Weiss, Barry H (398B)" <address@hidden>
> wrote:
> 
> >All,
> >
> >I trust you saw my note this morning on the use of dB.
> >
> >Please include dB relative to unit less measure as well as dB relative to
> >volts and dB relative to watts.
> >
> >Thanks,
> >
> >Barry
> >
> >On 8/7/14 10:47 AM, "Moroni, David F (398M)" <address@hidden>
> >wrote:
> >
> >>Hi Jonathan,
> >>
> >>Thank you for additional consideration and giving the green light.
> >>
> >>Best Regards,
> >>David
> >>
> >>
> >>On 8/7/14 9:11 AM, "Jonathan Gregory" <address@hidden> wrote:
> >>
> >>>Dear David
> >>>
> >>>The udunits database is not under our control, of course, but I
> >>>discussed
> >>>this
> >>>recently with Alison (copied), the manager of standard names. We agreed
> >>>that
> >>>dB should be allowed by CF.
> >>>
> >>>Best wishes
> >>>
> >>>Jonathan
> >>>
> >>>On Thu, Aug 07, 2014 at 02:49:35AM +0000, Moroni, David F (398M) wrote:
> >>>> From: "Moroni, David F (398M)" <address@hidden>
> >>>> To: Jonathan Gregory <address@hidden>
> >>>> CC: "Niedfeldt, John C (398M-Affiliate)"
> >>>><address@hidden>,
> >>>>  "address@hidden" <address@hidden>, CF
> >>>>  Metadata List <address@hidden>, John Graybeal
> >>>>  <address@hidden>
> >>>> Subject: Re: [CF-metadata] normalized_radar_backscatter_coefficient
> >>>> Date: Thu, 7 Aug 2014 02:49:35 +0000
> >>>> user-agent: Microsoft-MacOutlook/14.4.3.140616
> >>>>
> >>>> 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
> >>>>
> >>>> On 8/5/14 7:24 PM, "Moroni, David F (398M)"
> >>>><address@hidden>
> >>>> wrote:
> >>>>
> >>>> >Hi John,
> >>>> >
> >>>> >We will incorporate these constant coordinate variables as you've
> >>>> >recommended.
> >>>> >
> >>>> >Since during this 2+ month comment period we have not received any
> >>>> >objections on our proposed inclusion of
> >>>> >normalized_radar_backscatter_coefficient as a CF standard_name, we
> >>>>will
> >>>> >now proceed with applying this as a standard_name for our relevant
> >>>> >scatterometer datasets.
> >>>> >
> >>>> >On to our next concern: when will our proposed standard name become
> >>>> >officially adopted into the CF standard name listing?
> >>>> >
> >>>> >Timing is not super critical, but considering what I perceive to be a
> >>>> >consensus during this exchange of emails, we would at least like to
> >>>>obtain
> >>>> >a statement of confirmation from the CF folks that this standard name
> >>>>will
> >>>> >be adopted.
> >>>> >
> >>>> >A simple, brief email response from the chair or co-chair of this
> >>>> >committee would suffice.
> >>>> >
> >>>> >Thank you again for your consideration and generous feedback.
> >>>> >
> >>>> >Cheers,
> >>>> >David
> >>>> >
> >>>> >
> >>>> >On 7/23/14 9:32 PM, "John Graybeal" <address@hidden>
> >>>> >wrote:
> >>>> >
> >>>> >>Hi David,
> >>>> >>
> >>>> >>Thanks for the question. Constant coordinate variables are hopefully
> >>>>not
> >>>> >>a big deal -- they can be easily specified as scalar coordinate
> >>>> >>variables, as noted in the example here:
> >>>>
> >>>>>>http://cfconventions.org/Data/cf-convetions/cf-conventions-1.7/build/
> >>>>>>c
> >>>>>>f
> >>>>>>-c
> >>>> >>o
> >>>> >>nventions.html#scalar-coordinate-variables.
> >>>> >>
> >>>> >>That's an example for analysis time and pressure level, but it's OK
> >>>>to
> >>>> >>use coordinate variables for any critical reference variable.
> >>>>(Chapter 4:
> >>>> >>"Coordinate types other than latitude, longitude, vertical, and time
> >>>>are
> >>>> >>allowed." Incidentally, the text in reference [1] was proposed as a
> >>>> >>replacement for that sentence in
> >>>>http://kitt.llnl.gov/trac/ticket/100,
> >>>> >>which has been accepted but not implemented.)
> >>>> >>
> >>>> >>I had to search the archives to fully understand the motivation,
> >>>>here's
> >>>> >>what I found (ooh, FAQ question!):
> >>>> >>  (1) To locate the data in an axis other than space or time. [1]
> >>>> >>  (2) To provide a consistent way to specify the value of a certain
> >>>>other
> >>>> >>parameter, or even multiple parameters; if the parameter is
> >>>>unvarying, it
> >>>> >>can be specified as a scalar. [2]
> >>>> >>
> >>>> >>So your declaration that both the radiation wavelength and scatter
> >>>>angle
> >>>> >>were essential led to my suggestion. Adopting it standardizes the
> >>>>method
> >>>> >>for citing the needed information (consistent with other standard
> >>>>names,
> >>>> >>and across users of this standard name), thereby maximizing
> >>>> >>interoperability.
> >>>> >>
> >>>> >>By all means reply further if this seems problematic, I'm at the
> >>>>edge
> >>>>of
> >>>> >>my experience but others can jump in.
> >>>> >>
> >>>> >>John
> >>>> >>
> >>>> >>[1] On Apr 11, 2013, at 12:45, Jonathan Gregory
> >>>> >><address@hidden> wrote:
> >>>> >>
> >>>> >>> The commonest use of coordinate variables is to locate the data in
> >>>> >>>space and
> >>>> >>>  time, but coordinates may be provided for any other continuous
> >>>> >>>geophysical
> >>>> >>>  quantity (e.g. density, temperature, radiation wavelength, zenith
> >>>> >>>angle of
> >>>> >>>  radiance, sea surface wave frequency) or discrete category (see
> >>>> >>>Section 4.5,
> >>>> >>>  "Discrete axis", e.g. area type, model level number, ensemble
> >>>>member
> >>>> >>>number)
> >>>> >>>  on which the data variable depends.
> >>>> >>
> >>>> >>
> >>>> >>[2] On Dec 24, 2010, at 13:26, Jonathan Gregory
> >>>> >><address@hidden> wrote:
> >>>> >>
> >>>> >>>  We quite often recommend, for instance in connection with
> >>>>particular
> >>>> >>>standard names,
> >>>> >>> that the value of a certain other parameter could be specified,
> >>>>e.g. a
> >>>> >>> radiation_wavelength for radiative quantities. Scalar coord vars
> >>>>are a
> >>>> >>>neat
> >>>> >>> way to do this. They are something between multivalued coord vars
> >>>>and
> >>>> >>> attributes in terms of function: easier than coord vars, and more
> >>>> >>>powerful
> >>>> >>> than attributes because they can themselves have attributes.
> >>>> >>
> >>>> >>[3]
> >>>> >>
> >>>> >>
> >>>> >>On Jul 23, 2014, at 17:39, Moroni, David F (398M)
> >>>> >><address@hidden> wrote:
> >>>> >>
> >>>> >>> Hi John (G),
> >>>> >>>
> >>>> >>> John (N) and myself are working together on this effort.
> >>>> >>>
> >>>> >>> Thanks for your inputs here.
> >>>> >>>
> >>>> >>> In general, I agree with the first part of your revision of the
> >>>> >>>description, but I don't suggest including a reference to the
> >>>>coordinate
> >>>> >>>values for the other standard names as you've suggested, namely
> >>>> >>>"radiation_wavelength" and "scattering_angle", simply because this
> >>>>type
> >>>> >>>of measurement assumes: 1) constant wavelength and 2) constant
> >>>> >>>scattering angle. I simply don't follow your reasoning for why such
> >>>> >>>coordinate values would be needed given the nature of these values
> >>>>being
> >>>> >>>constant. Can you provide some rationale as to why we would want to
> >>>>list
> >>>> >>>these as coordinate values?
> >>>> >>>
> >>>> >>> Cheers,
> >>>> >>> David
> >>>> >>>
> >>>> >>> ==================================================
> >>>> >>> David Moroni
> >>>> >>> Ocean Wind and Scatterometry Data Engineer
> >>>> >>> Physical Oceanography Distributed Active Archive Center
> >>>> >>> Jet Propulsion Laboratory
> >>>> >>> 4800 Oak Grove Dr
> >>>> >>> M/S 158-242
> >>>> >>> Pasadena, CA 91109
> >>>> >>> Phone:  818.354.2038
> >>>> >>> Fax:  818.353.2718
> >>>> >>> ==================================================
> >>>> >>>
> >>>> >>> From: John Graybeal <address@hidden>
> >>>> >>> Date: Wednesday, July 23, 2014 3:52 PM
> >>>> >>> To: "Niedfeldt, John C (398M-Affiliate)"
> >>>> >>><address@hidden>
> >>>> >>> Cc: CF Metadata List <address@hidden>, David F Moroni
> >>>> >>><address@hidden>
> >>>> >>> Subject: Re: [CF-metadata]
> >>>>normalized_radar_backscatter_coefficient
> >>>> >>>
> >>>> >>>> Hi John (N),
> >>>> >>>>
> >>>> >>>> Thanks for the detailed explanation. I am convinced the new term
> >>>>is
> >>>> >>>>distinct. I did not expect to redefine the old term unless one was
> >>>> >>>>clearly a refinement of the other, which is not the case.
> >>>> >>>>
> >>>> >>>> I still am concerned about the description I think you are
> >>>>proposing
> >>>> >>>>for this term ("normalized_radar_backscatter_coefficient is also
> >>>>called
> >>>> >>>>the normalized radar cross section, which are commonly used in the
> >>>> >>>>microwave remote sensing community.") Based on your inputs, here
> >>>>is
> >>>>a
> >>>> >>>>second attempt:
> >>>> >>>>
> >>>> >>>>> The fraction of incident power at a given wavelength that
> >>>>reaches
> >>>>a
> >>>> >>>>>receiver, after reflection by a surface at a given reflection
> >>>>angle.
> >>>> >>>>>(In microwave remote sensing this is also known as  the
> >>>>'normalized
> >>>> >>>>>radar cross section' or 'sigma naught'.) Coordinate values for
> >>>> >>>>>radiation wavelength and reflection angle should be given the
> >>>>standard
> >>>> >>>>>names radiation_wavelength and scattering_angle.
> >>>> >>>>
> >>>> >>>> This description reflects: always 1 wavelength; always 1 backward
> >>>> >>>>scattering angle; and that all lost power is included in the
> >>>> >>>>coefficient, not simply the surface reflectance/absorption.
> >>>> >>>>
> >>>> >>>> If I correctly got your 3 points, the term "attenuated" applies,
> >>>>as it
> >>>> >>>>is used elsewhere in CF: "'The attenuated backwards scattering
> >>>>function
> >>>> >>>>includes the effects of two-way attenuation by the medium between
> >>>>a
> >>>> >>>>radar source and receiver." Since I can't imagine needing an
> >>>> >>>>unattenuated backscatter coefficient, the extra word seems
> >>>>unneeded
> >>>>for
> >>>> >>>>this name.
> >>>> >>>>
> >>>> >>>> John (G)
> >>>> >>>>
> >>>> >>>> On Jul 23, 2014, at 10:37, Niedfeldt, John C (398M-Affiliate)
> >>>> >>>><address@hidden> wrote:
> >>>> >>>>
> >>>> >>>>> Dear John et al,
> >>>> >>>>> Here are three major distinctions between the
> >>>> >>>>>surface_backwards_scattering_coefficient_of_radar_wave (old) and
> >>>> >>>>>normalized_radar_backscatter_coefficient (new):
> >>>> >>>>>    ??? The (old) definition has the default definition as being an
> >>>> >>>>>integral over all wavelengths, but the radar backscatter
> >>>>coefficient
> >>>> >>>>>is always measured using one wavelength (new) and must always be
> >>>> >>>>>specified.
> >>>> >>>>>    ??? The part about scattering radiation having no loss in
> >>>>energy
> >>>>in
> >>>> >>>>>the (old) definition is not clear, but in practice and theory
> >>>>energy
> >>>> >>>>>is always lost once the initial wave is transmitted (indeed, it
> >>>>is
> >>>>in
> >>>> >>>>>part the loss due to the ground that we are measuring)(new).
> >>>> >>>>>    ??? The backscatter in the (old) definition refers to summing
> >>>>all
> >>>> >>>>>backwards scattering angles, where in remote sensing we look at
> >>>>just
> >>>> >>>>>one backscatter angle (new).
> >>>> >>>>> And yes, if the old variable pertains to the normalized radar
> >>>>cross
> >>>> >>>>>section--which I believe it does not--then the transmitted
> >>>>wavelength
> >>>> >>>>>and backscatter angle (elevation angle) should be required as
> >>>>they
> >>>>are
> >>>> >>>>>essential to understanding the product and being able to
> >>>>correlate
> >>>>and
> >>>> >>>>>verify data.
> >>>> >>>>>
> >>>> >>>>> So yes, we could change the old definition to meet the new
> >>>>needs,
> >>>>but
> >>>> >>>>>it would require a change in base assumptions that would render
> >>>>any
> >>>> >>>>>current data using that standard name as invalid. For these
> >>>>reasons
> >>>> >>>>>and more, I believe we should make a new standard name. The
> >>>>definition
> >>>> >>>>>I have provided is accurate and once approved additional
> >>>>attributes
> >>>> >>>>>and values can be made required to suit all needs for those
> >>>>dealing
> >>>> >>>>>with the normalized radar backscatter coefficient.
> >>>> >>>>>
> >>>> >>>>> Sincerely,
> >>>> >>>>> John
> >>>> >>>>>
> >>>> >>>>> --
> >>>> >>>>> John Niedfeldt
> >>>> >>>>> Data Engineering
> >>>> >>>>> PO.DAAC, JPL
> >>>> >>>>>
> >>>> >>>>> From: John Graybeal <address@hidden>
> >>>> >>>>> Date: Tuesday, July 22, 2014 at 3:53 PM
> >>>> >>>>> To: JPL <address@hidden>
> >>>> >>>>> Cc: CF Metadata List <address@hidden>, "Moroni, David
> >>>>F
> >>>> >>>>>(398M)" <address@hidden>
> >>>> >>>>> Subject: Re: [CF-metadata]
> >>>>normalized_radar_backscatter_coefficient
> >>>> >>>>>
> >>>> >>>>> John, I think we (I, anyway) were waiting for a little more
> >>>> >>>>>clarification as to what was needed. Sorry for that delay.  I
> >>>>like
> >>>>the
> >>>> >>>>>name itself, makes sense to me.
> >>>> >>>>>
> >>>> >>>>> Unless I am mistaken, from your email I infer that the meaning
> >>>>of
> >>>> >>>>>this is a narrow case of
> >>>> >>>>>surface_backwards_scattering_coefficient_of_radar_wave.  That
> >>>> >>>>>description is:
> >>>> >>>>>> The scattering/absorption/attenuation coefficient is assumed to
> >>>>be
> >>>> >>>>>>an integral over all wavelengths, unless a coordinate of
> >>>> >>>>>>radiation_wavelength is included to specify the wavelength.
> >>>> >>>>>>Scattering of radiation is its deflection from its incident path
> >>>> >>>>>>without loss of energy. Backwards scattering refers to the sum
> >>>>of
> >>>> >>>>>>scattering into all backward angles i.e. scattering_angle
> >>>>exceeding
> >>>> >>>>>>pi/2 radians. Ascattering_angle should not be specified with
> >>>>this
> >>>> >>>>>>quantity.
> >>>> >>>>>
> >>>> >>>>> I can't tell from the description if this item is different, so
> >>>>the
> >>>> >>>>>description could use a little bit more meat to tease that out.
> >>>> >>>>>Looking at your thread, I see this:
> >>>> >>>>>
> >>>> >>>>>> we are calculating sigma_naught which is the fraction of
> >>>>incident
> >>>> >>>>>>power that is reflected by the surface. It is also very
> >>>>important
> >>>>in
> >>>> >>>>>>scatterometry to record the angle of incidence as the
> >>>>sigma_naught
> >>>> >>>>>>changes based on the incidence angle in addition to various
> >>>>other
> >>>> >>>>>>parameters which are essential to being able to correlate data
> >>>>from
> >>>> >>>>>>various scatterometers.
> >>>> >>>>>
> >>>> >>>>> So does it work for the description could say something like the
> >>>> >>>>>following? This is still similar to the other standard name, so
> >>>>if
> >>>> >>>>>there are specific things that make the distinction clear that
> >>>>would
> >>>> >>>>>be important to add. ("This differs from surface_backwards_...")
> >>>> >>>>>
> >>>> >>>>>> The fraction of incident power that is reflected by the
> >>>>surface.
> >>>>(In
> >>>> >>>>>>microwave remote sensing this is also known as  the 'normalized
> >>>>radar
> >>>> >>>>>>cross section' or 'sigma naught', when produced from one angle
> >>>>of
> >>>> >>>>>>incidence and from one wavelength.) Scattering of radiation is
> >>>>its
> >>>> >>>>>>deflection from its incident path without loss of energy.
> >>>>Backwards
> >>>> >>>>>>scattering refers to the sum of scattering into all backward
> >>>>angles
> >>>> >>>>>>i.e. scattering_angle exceeding pi/2 radians. A scattering_angle
> >>>> >>>>>>should not be specified with this quantity. Coordinates of
> >>>> >>>>>>radiation_wavelength and angle_of_incidence are used to specify
> >>>>those
> >>>> >>>>>>baseline parameters.
> >>>> >>>>>
> >>>> >>>>> I'm not sure about the last part -- if they are always needed
> >>>>these
> >>>> >>>>>variables should be required.
> >>>> >>>>>
> >>>> >>>>> John
> >>>> >>>>>
> >>>> >>>>>
> >>>> >>>>>
> >>>> >>>>> On Jul 22, 2014, at 14:49, Niedfeldt, John C (398M-Affiliate)
> >>>> >>>>><address@hidden> wrote:
> >>>> >>>>>
> >>>> >>>>>> Dear all,
> >>>> >>>>>> Hello again! About two months back I sent in a request, which
> >>>>is
> >>>> >>>>>>referenced below, in which I requested that we add the
> >>>> >>>>>>??normalized_radar_backscatter_coefficient?? in CF. Having heard
> >>>> >>>>>>nothing to the contrary, and seeing as no other standards name
> >>>>match
> >>>> >>>>>>our needs, we at PO.DAAC will be moving forward in implementing
> >>>>this
> >>>> >>>>>>new standard name.
> >>>> >>>>>>
> >>>> >>>>>> As our newly reprocessed netCDF datasets shall soon serve as an
> >>>> >>>>>>online replacement for existing datasets already in use by
> >>>>hundreds
> >>>> >>>>>>of interdisciplinary scatterometry data users, we hope to
> >>>>likewise
> >>>> >>>>>>hear back from you soon as to whether there is consensus on our
> >>>> >>>>>>proposed standard name. If there is anything further we can do
> >>>>to
> >>>> >>>>>>build community consensus on our proposed standard name, please
> >>>>let
> >>>> >>>>>>me know.
> >>>> >>>>>>
> >>>> >>>>>> Sincerely,
> >>>> >>>>>> John
> >>>> >>>>>>
> >>>> >>>>>> --
> >>>> >>>>>> John Niedfeldt
> >>>> >>>>>> Data Engineering
> >>>> >>>>>> PO.DAAC, JPL
> >>>> >>>>>>
> >>>> >>>>>> From: Lauret Olivier <address@hidden>
> >>>> >>>>>> Date: Friday, May 30, 2014 at 8:11 AM
> >>>> >>>>>> To: "address@hidden" <address@hidden>
> >>>> >>>>>> Cc: JPL <address@hidden>
> >>>> >>>>>> Subject: TR: normalized_radar_backscatter_coefficient
> >>>> >>>>>>
> >>>> >>>>>> Hi all,
> >>>> >>>>>>
> >>>> >>>>>> Just forwarding you some discussion we have with J. Niedfeldt
> >>>>about
> >>>> >>>>>>some standard name for sigma naught variable. I thought the
> >>>>available
> >>>> >>>>>>??surface_backwards_scattering_coefficient_of_radar_wave?? could
> >>>>be
> >>>> >>>>>>used considering some changes in the definition [in short I wish
> >>>>we
> >>>> >>>>>>could mix the description of sigma naught from radar altimetry
> >>>>with
> >>>> >>>>>>the one from scatterometers]. But it seems that the quantities
> >>>>are
> >>>> >>>>>>different enough to introduce a new standard name (see the
> >>>>message
> >>>> >>>>>>below).
> >>>> >>>>>>
> >>>> >>>>>> Can we introduce  ??normalized_radar_backscatter_coefficient??
> >>>>in CF?
> >>>> >>>>>>
> >>>> >>>>>> Thanks,
> >>>> >>>>>>
> >>>> >>>>>> Olivier
> >>>> >>>>>>
> >>>> >>>>>> De : Niedfeldt, John C (398M-Affiliate)
> >>>> >>>>>>[mailto:address@hidden]
> >>>> >>>>>> Envoy?? : jeudi 29 mai 2014 21:26
> >>>> >>>>>> ?? : Lauret Olivier
> >>>> >>>>>> Objet : normalized_radar_backscatter_coefficient
> >>>> >>>>>>
> >>>> >>>>>> Dear Mr. Olivier,
> >>>> >>>>>> After discussion  with Dr. David Long of BYU and reviewing the
> >>>> >>>>>>current definition with him it was determined that we do in fact
> >>>>need
> >>>> >>>>>>a new variable. In microwave remote sensing the normalized radar
> >>>> >>>>>>cross section, sigma naught, is always produced from one angle
> >>>>of
> >>>> >>>>>>incidence and from one wavelength. I understand the desire to
> >>>> >>>>>>consolidate the number of standard names and to not have
> >>>>duplication,
> >>>> >>>>>>but adding this standard name would reduce confusion and error
> >>>>for
> >>>> >>>>>>many I believe. It is also general enough that we can add
> >>>>attributes
> >>>> >>>>>>to it in the future to allow further specification for various
> >>>> >>>>>>endeavors. If you have any more questions feel free to contact
> >>>>me
> >>>>and
> >>>> >>>>>>thank you again for your assistance. We changed the
> >>>>standard_name
> >>>>to
> >>>> >>>>>>be more descriptive.
> >>>> >>>>>>
> >>>> >>>>>> standard_name:
> >>>> >>>>>> normalized_radar_backscatter_coefficient
> >>>> >>>>>>
> >>>> >>>>>> Definition:
> >>>> >>>>>> normalized_radar_backscatter_coefficient is also called the
> >>>> >>>>>>normalized radar cross section, which are commonly used in the
> >>>> >>>>>>microwave remote sensing community.
> >>>> >>>>>>
> >>>> >>>>>> Canonical Units:
> >>>> >>>>>> 1
> >>>> >>>>>>
> >>>> >>>>>>
> >>>> >>>>>> Sincerely,
> >>>> >>>>>> John Niedfeldt
> >>>> >>>>>>
> >>>> >>>>>>
> >>>> >>>>>> Cliquez ici si ce message est ind??sirable (pourriel).
> >>>> >>>>>>
> >>>> >>>>>> _______________________________________________
> >>>> >>>>>> CF-metadata mailing list
> >>>> >>>>>> address@hidden
> >>>> >>>>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >>>> >>>>>
> >>>> >>>>> _______________________________________________
> >>>> >>>>> CF-metadata mailing list
> >>>> >>>>> address@hidden
> >>>> >>>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: VZX-973749
Department: Support UDUNITS
Priority: Critical
Status: Closed