On Fri, 19 Sep 2008, kuiper@jpl.nasa.gov wrote:

CLASS itself can write SDFITS files, and to my knowledge is the
only converter around.

HELP LAS\FITS
within CLASS will tell you how to do that. It just mentions
a BINTABLE file, but that BINTABLE does follow the SDFITS
convention.

Does anyone know of a CLASS to SDFITS converter?

Regards

Tom

080917

Dear Bill Pence and FITS community,

reading about the proposed SIP conventions I would like
to draw your attention to the most commonly seen, pure
optical distortion (3rd order) term. This could be
expressed with the SIP mechanism, however typically
a single coefficient is applicable for many telescopes
to control "distortion" (besides the knowledge of the
"center" i.e. the location of the optical axis on the
detector, which I see is already handled).

Let D3 be the coefficient of (3rd order) optical distortion,
and dx, dy the corrections to be applied to the x, y
coordinates (e.g. in pixel unit), then

dx = D3 * x * r**2
dy = D3 * y * r**2

with r**2 = x**2 + y**2

This is to announce the start of the 30-day Public Comment Period on
2 FITS conventions that deal with geometric distortions in images. The
first convention, called Simple Imaging Polynomial or SIP, represents
non-linear geometric distortion of the coordinate system via polynomial
coefficients in FITS header keywords.

The second convention, called TNX, extends the standard tangent plane
WCS convention by adding a non-linear distortion function defined by
polynomial coefficients that are stored using indexed WATj_nnn keywords.

Detailed information about these conventions is available for public
review and comment from the FITS registry web page at

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

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.

Douglas S. Brenner wrote:

Many software analysis packages provide tools to copy keywords from one
file to another or extract a single HDU out of a multi-hdu file.

One standalone tool that could help with this is fv
(http://heasarc.gsfc.nasa.gov/docs/software/ftools/fv/). It could be
used to manually cut and paste each keyword from the primary HDU to the
second HDU.

Bill Pence

Hope I'm in the right place.

I have a fits file with the desired header in the first HDU test.fits
[0] and the data in the second test.fits[1]. I need to combine it
into one file that works in ds9. How do I do this?

Thanks.

-----------------------------------------
Douglas Brenner, Ph.D
-----------------------------------------
Research Scientist
Department of Astrophysics
American Museum of Natural History
79th Street at Central Park West
New York, NY 10024-5192
tel: 212-313-7633
fax: 212-769-5007
Web: http://lyot.org

Hope I'm in the right place.  I have a fits file with the desired header in the first HDU test.fits[0] and the data in the second test.fits[1].  I need to combine it into one file that works in ds9.  How do I do this? Thanks. ----------------------------------------- Douglas Brenner, Ph.D ----------------------------------------- Research Scientist Department of Astrophysics American Museum of Natural History 79th Street at Central Park West New York, NY 10024-5192 tel: 212-313-7633 fax: 212-769-5007 Web: http://lyot.org

William Pence wrote:

The question below regarding WCS keyword usage was sent to the FITS
support office. Is Table 8.1 in the FITS Standand incorrect? (See
http://fits.gsfc.nasa.gov/fits_standard.html ).
Should it state that LONPOLEa and LATPOLEa
are associated with PVi_3a and PVi_4a instead of PVi_1a and PVi_2a?

Bill

-------- Original Message --------
Subject: PV index perhaps wrong in version 3.0
Date: Mon, 08 Sep 2008 14:35:34 +0200

L.S.,

Table 8.1 section 8, page 74 lists for the native longitude and latitude
of the celestial pole the keywords LONPOLEa= and LATPOLEa= which,
according to the table is equivalent to PVi_1a and PVi_2a.
However, in the same table these keywords were previously attached to
the fiducial point. Also Calabretta and Greisen use PVi_3a and PVi_4a in
their article 'Representations of celestial coordinates in FITS'.
Please can you inform me about what is right (i.e. standard FITS) in
this case?

I'd rearrange the Definition to say earlier what a REGION table is and
offers, for anyone else who might wish to adopt this convention. At
the moment the introduction tells how it's implemented before saying
what is it.

It doesn't state to which data the region is applicable. Is the
convention limited to the primary data array or does it include any
IMAGE extensions? If not, is there a way to association a region with
a specific array? Can there be more than one REGION table in a FITS
file?

It assumes more prior knowledge of the reader than I would expect. For
example, what's GTI? It would help to have a reference or URL to GTI,
the IVOA STC Region syntax, OGIP/94-006, ACIS. Please can "in the
usual way" in the first bullet of Section 2 be made explicit.

It wasn't clear which if any keywords are defined by the convention,
such as MFORM1. In the example file I noticed an MFORM2 keyword.
Required keywords from other conventions like HDU* and MFORMn should
be referenced.

Aren't the long-string convention headers (even all the optional headers)
in Section 3 a distraction from the essence of the convention?

This is to announce the start of the 30-day Public Comment Period on
the FITS Region File convention which has been submitted for inclusion
in the Registry of FITS Conventions. This is the 12th in a growing
series of conventions submitted to the Registry which is maintained by
the IAU FITS Working Group.

Detailed information about 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

A FITS Region file is a FITS binary table that defines a spatial region
of a 2-dimensional image. The region file is often used to define an
area that is to be included or excluded from certain data processing
operations on the image. The region is specified as the union or
intersection of geometric shapes, such as 'circle' or 'rectangle'. The
REGION table is the FITS equivalent of the ASCII text region file that
has long been used by the ds9 image processing program and its
predecessor, SAOimage.