Difference between revisions of "CF"

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==Get Involved: Monthly Telecons==
==Get Involved: Monthly Telecons==
:Next telecon:  
:Next telecon:  
::Monday Dec 12, 3pm ET / 12noon PT
::Tuesday Jan 17, 2pm ET / 11am PT (tentative)
::Dial: 877-668-4493
::Dial: 877-668-4493
::Access code: 23138379
::Access code: 23138379
:::Winter Meeting Plans
:::Winter Meeting Plans
:::Selection of Cluster Chair
:Minutes of past telecons/meetings:
:Minutes of past telecons/meetings:
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::Pre-define band names
::Pre-define band names
::Pre-define by wavelength/frequency range
::Pre-define by wavelength/frequency range
::[[Spectral_Band|Proposal by Tom Whittaker]]
:2. Data quality
:2. Data quality
::Modifiers such as "percent_cloud_free"
::Modifiers such as "percent_cloud_free"
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== CF-Aware Tools ==
== CF-Aware Tools ==
==Spectral Band Proposal by Tom Whittaker==
Create standard_names that can be recognized by applications as
being the special "band dimension" variable (similar to "time").
The name of this dimension variable would not, however, be specified,
but inferred from its attributes.
Create two coordinate axis types ("wavelength" and "wavenumber")
that can be recognized by the NetCDF library as defining a "spectral
Thus, the band dimension might be declared:
:<variable name="band" shape="band" type="float" >
::<attribute name="standard_name" value="wavelength" />
::<attribute name="units" value = "cm" />
::<attribute name="_CoordinateAxisType" value = "wavelength" />
The dimension variable can then be used to dimension arrays associated
with the spectral channels, e.g., wavelength boundaries for each band
(channel), units, scaling, etc.  The use of these (dimensioned)
variables, however, would be up to the application developers rather
than made part of the conventions, per se.
This would necessitate creating perhaps two new standard_names:
'''wavelength''' (there is already a "radiation_wavelength" with
"electromagnetic_wavelength" as an alias, but I don't see an
issue for making just "wavelength" a standard name, either.  I also
recognize that in most cases this refers to the center wavelength of
the band/channel, and perhaps should be so designated...?).
'''wavenumber'''  (There is no equivalent standard_name.  Again, I imagine this would actually refer to a center wavenumber).
We would also then need to define two new coordinate axis types:
wavelength and wavenumber.
For the case where people don't or can't use the dimension variable as
a coordinate variable, we recommend that they use the convention name
"band" as the dimension variable so that applications can at least
recognize this for what it is.
In all cases, new (dimensioned) variables could then be used to
specify band-specific attributes.  For example:
:<variable name="minimum_wavelength" shape="band" type="double">
::<attribute name="units" value="cm" />
== Join the Cluster e-mail list ==
== Join the Cluster e-mail list ==

Revision as of 13:41, January 6, 2012

The CF Standards Cluster


Propose extensions to the CF naming conventions that are relevant to observational data
Create use cases and interoperability demos that demonstrate the value of CF usage in remote sensing
Provide tutorials at Federation meetings on the use of the CF conventions

Get Involved: Monthly Telecons

Next telecon:
Tuesday Jan 17, 2pm ET / 11am PT (tentative)
Dial: 877-668-4493
Access code: 23138379
Winter Meeting Plans
Minutes of past telecons/meetings:

Possible CF Extensions

1. Spectral bands
Define as dimension rather than coordinate variable
Pre-define band names
Pre-define by wavelength/frequency range
Proposal by Tom Whittaker
2. Data quality
Modifiers such as "percent_cloud_free"
3. Swath geometry
Orbital parameters
4. Engineering parameters
Calibration tables

CF-Aware Tools

Join the Cluster e-mail list


External Links

CF Home Page


Read the CF-satellite archives (UCAR):


Join the CF-satellite e-mail list (UCAR):



Interim Chair: Rob Raskin raskin at jpl.nasa.gov