[fitsbits] Start of the 'INHERIT' Public Comment Period

I have to express some concern about registering the INHERIT convention.
The documentation notes a number of potential problems that can occur when
FITS software that is unaware of the convention is used to read, interpret,
and write new copies of files that use INHERIT. I consulted with Perry
Greenfield, one of the authors of the document, as to whether these problems
arise in practice or not. He said yes, indeed, they do, and that he would
prefer to discourage people from using the convention.

If we are to include INHERIT in the FITS registry, we should perhaps do so
solely to document the practice. However, it seems to me too fragile a
construct to recommend for wider adoption. It would be cleaner, I think, to
define more clearly the rules for how primary headers pertain to extension
headers (e.g., the concept of inheritance applies by default, or whatever).
This is something we might recommend to the recently formed FITS review
panel to discuss.

Bob


On 3/23/07 4:06 PM, "William Pence" wrote:

This is to announce the start of the 30-day Public Comment Period on the
'INHERIT' FITS convention that has been submitted by the Nelson Zarate
and Perry Greenfield for inclusion in the 'Registry of FITS Conventions'
that is maintained by the IAU FITS Working Group. This is the 4th in a
growing series of conventions submitted for inclusion in the Registry.

A document describing this convention and a sample FITS file that uses
it are available for public review and comment from the FITS registry
web page at

http://fits.gsfc.nasa.gov/fits_registry.html

Under this convention, the presence of the keyword INHERIT = T in an
extension header indicates that the extension should inherit the
keywords from the primary header (except for the mandatory and
commentary keywords)

Comments may be posted here on the FITSBITS mail exploder or the
sci.astro.fits newsgroup. Minor typographical issues may be sent
directly to the authors of the convention.

Bill Pence
(on behalf of the IAU FITS Working Group)

The "Extent of Usage" bullet could be extended with something like:
"Also used by various instruments and data pipelines operated by, or
partly by, the United Kingdom, such as INT/WFC, UKIRT/WFCAM and
ESO/VISTA/VIRCAM."

Peter.

On 4/12/07, Peter Bunclark wrote:
The "Extent of Usage" bullet could be extended with something like:
"Also used by various instruments and data pipelines operated by, or
partly by, the United Kingdom, such as INT/WFC, UKIRT/WFCAM and
ESO/VISTA/VIRCAM."

The data reduction pipeline run at UKIRT for WFCAM does not use FITS
files, so perhaps this should read "CASU/WFCAM" instead.

Cheers,
Brad.

--
Brad Cavanagh, Data Reduction Software Engineer
Joint Astronomy Centre, Hilo, Hawaii
/ +1-808-969-6555

Brad Cavanagh wrote:
On 4/12/07, Peter Bunclark wrote:

The "Extent of Usage" bullet could be extended with something like:
"Also used by various instruments and data pipelines operated by, or
partly by, the United Kingdom, such as INT/WFC, UKIRT/WFCAM and
ESO/VISTA/VIRCAM."


The data reduction pipeline run at UKIRT for WFCAM does not use FITS
files, so perhaps this should read "CASU/WFCAM" instead.

Cheers,
Brad.

Indeed, it is only the UK pipeline that supplies science products to the
community, and raw data to ESO as part of our international partnership,
which naturally requires raw WFCAM frames to be converted to FITS. The
name of the telescope remains "UKIRT", however... Since we're talking
about a FITS-convention registry, does that little bit of internal
politics really matter? Clearly this registry does not apply to the
original NDF files.

Pete.