From owner-fitsbits at marmoset.cv.nrao.edu Fri Jul 4 09:53:00 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id JAA00171; œFri, 4 Jul 1997 09:53:00 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id EAA32303; Fri, 4 Jul 1997 04:02:40 -0400 Received: from solitaire.cv.nrao.edu (news at solitaire.cv.nrao.edu [192.33.115.79]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with SMTP id EAA18496 for ; Fri, 4 Jul 1997 04:02:35 -0400 (EDT) Received: by solitaire.cv.nrao.edu (4.1/DDN-CV/1.10) id AA04274; Fri, 4 Jul 97 04:02:32 EDT To: fitsbits at fits.cv.nrao.edu Date: Thu, 03 Jul 1997 07:34:05 -0400 From: Tom Perry Message-Id: <33BB8E2D.22335B63 at sprynet.com> Organization: A.S.S.N.E., Inc. Path: solitaire.cv.nrao.edu!newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!newsfeed.internetmci.com!netnews.nwnet.net!news-hub.interserv.net!news.sprynet.com!not-for-mail Subject: Windows/DOS Fits File Editor Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Can anyone direct me to a Windows or Dos program that can read FITS files, edit the header to add or change keywords, and re-write the file? Everything I can find is scientific in nature and does not run under Windows or Dos. Thanks, Tom Perry From owner-fitsbits at marmoset.cv.nrao.edu Sat Jul 5 12:01:43 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id MAA03184; œSat, 5 Jul 1997 12:01:43 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id CAA01859; Sat, 5 Jul 1997 02:28:27 -0400 Received: from solitaire.cv.nrao.edu (news at solitaire.cv.nrao.edu [192.33.115.79]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with SMTP id CAA19700 for ; Sat, 5 Jul 1997 02:28:21 -0400 (EDT) Received: by solitaire.cv.nrao.edu (4.1/DDN-CV/1.10) id AA24729; Sat, 5 Jul 97 02:28:17 EDT To: fitsbits at fits.cv.nrao.edu Date: Sat, 05 Jul 1997 08:04:51 +0200 From: "Venno G.J.S. Cladder" Message-Id: <33BDE403.7969 at introweb.nl> Organization: Cladder Computer Service & Euregio Publiekscentrum voor Sterrenkunde Path: solitaire.cv.nrao.edu!newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!europa.clark.net!dispatch.news.demon.net!demon!fido.news.demon.net!demon!sun4nl!sun4nl!Eindhoven.NL.net!not-for-mail References: <33BB8E2D.22335B63 at sprynet.com> Reply-To: V.Cladder at net.HCC.nl Subject: Re: Windows/DOS Fits File Editor Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Hi Tom! Tom Perry wrote: > Can anyone direct me to a Windows or Dos program that can read FITS files, edit > the header to add or change keywords, and re-write the file? > Everything I can find is scientific in nature and does not run under Windows or > Dos. As I wrote to an Italian contributor: there is a program Graphic Worshop for Windows which can a t least convert FITS, but may not be exactly what you're looking for. Have a try at: http://www.mindworkshop.com/alchemy/alchemy.html Warm reagrds, Venno Cladder From owner-fitsbits at marmoset.cv.nrao.edu Wed Jul 9 10:20:06 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id KAA15122; œWed, 9 Jul 1997 10:20:06 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id EAA14475; Wed, 9 Jul 1997 04:24:13 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id EAA01631 for ; Wed, 9 Jul 1997 04:24:10 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id EAA08371; Wed, 9 Jul 1997 04:24:09 -0400 To: fitsbits at fits.cv.nrao.edu Date: Wed, 9 Jul 1997 08:02:08 GMT From: Dez Futak Message-ID: <33C3457F.FCCFCF9C at bris.ac.uk> Organization: University of Bristol, England Path: newsfeed.cv.nrao.edu!hearst.acc.Virginia.EDU!uunet!in3.uu.net!194.87.0.28!demos!news.maxwell.syr.edu!dispatch.news.demon.net!demon!delos.dra.hmg.gb!server1.netnews.ja.net!warwick!bris.ac.uk!usenet Subject: Creating FITS files from 12 bit data from A/D converter.. Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk I'm attempting to convert 12 Bit data from my A/D converter into FITS format for later use with AIPS... Can anyone point me in the right direction as to how to go about this? Many thanks, Dez Futak Co-ordinator of BSRA. From owner-fitsbits at marmoset.cv.nrao.edu Wed Jul 9 17:19:06 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id RAA16060; œWed, 9 Jul 1997 17:19:06 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id QAA15984; Wed, 9 Jul 1997 16:51:24 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id QAA00696 for ; Wed, 9 Jul 1997 16:51:22 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id QAA06875; Wed, 9 Jul 1997 16:51:21 -0400 To: fitsbits at fits.cv.nrao.edu Date: 9 Jul 1997 16:22 EDT From: bschlesinger at nssdca.gsfc.nasa.gov (Barry M. Schlesinger) Message-ID: <9JUL199716225708 at nssdca.gsfc.nasa.gov> Organization: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!newshub2.home.com!newshub1.home.com!news.home.com!nick.arc.nasa.gov!newsfeed.gsfc.nasa.gov!nssdca.gsfc.nasa.gov!bschlesinger Reply-To: fits at nssdca.gsfc.nasa.gov Subject: Sources of FITS Information Newsgroups: sci.astro.fits,sci.answers,news.answers Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Archive-name: astronomy/fits/info-sources Last-modified: 1997/07/09 -------- Sources of FITS Information Preface This material on sources of Flexible Image Transport System (FITS) information is posted and updated periodically by the FITS Support Office at the NASA Goddard Space Flight Center (GSFC). It discusses where general FITS information, including some answers to frequently asked questions, can be found, and provides sources for detailed information on FITS software and documentation. ------- FITS Support Office The FITS Support Office maintains a library of FITS information accessible via http://ssdoo.gsfc.nasa.gov/astro/fits/fits_home.html or ftp://nssdc.gsfc.nasa.gov/pub/fits/. The material available includes o "Definition of FITS", a codification of FITS for the NASA/Science Office of Standards and Technology (NOST), available in LaTeX, uncompressed PostScript, compressed PostScript and (often) ASCII text o "A User's Guide to FITS", published by the FITS Support Office, in LaTeX, and compressed and uncompressed PostScript o Revisions to version 1.0 of the "Definition of FITS" covering the specification of units, which were incorporated into version 1.1 (text) o A current list of the extension type (structure) names registered with the International Astronomical Union FITS Working Group (IAUFWG) (text) o Rules for physical blocking on various media adopted by the IAUFWG (text) o The proposal under discussion by the FITS committees for a format with a four-digit year for DATExxxx keyword values In the same directory but accessible directly via http://ssdoo.gsfc.nasa.gov/astro/fits/basics_info.html is the FITS Basics and Information that used to be regularly posted to sci.astro.fits and sci.data.formats. It continues to be revised to reflect current FITS developments. It contains the following material: o An overview of FITS o A list of FITS documents o A list of software packages that support FITS, including FITS <--> image converters for various platforms o A list of on-line FITS resources o A description of the FITS Support Office The hypertext version provides links to many of the documents, software, and network locations listed. The text version provides information on how to obtain much of this material. There is also a hypertext version of the List of Registered Extensions. Links from the Web page and subdirectories of the ftp directory contain o Software developed by the FITS Support Office. o Error test files: primary HDUs useful for testing the ability of software designed to read FITS files to cope with files that have errors or are non-standard. These files should be downloaded in binary form. Printed copies of the material in the FITS directory can be obtained from the Coordinated Request and User Support Office (CRUSO): (Postal) Coordinated Request and User Support Office Code 633 National Space Science Data Center NASA Goddard Space Flight Center Greenbelt MD 20771 USA (Electronic mail) request at nssdca.gsfc.nasa.gov (Telephone) +1-301-286-6695 8:00 A. M. - 4:30 P.M. U. S. Eastern Time (-0500 from the last Sunday in October through the first Saturday in April; -0400 the remainder of the year) When no one is available, messages can be left on voice mail. (FAX) +1-301-286-1635 ------- National Radio Astronomy Observatory (NRAO) A FITS Archive can be found at URL http://fits.cv.nrao.edu/ or at ftp://fits.cv.nrao.edu/fits, located at NRAO. This machine supports a WAIS server named nrao-fits which has an index of all of the FITS-related text files in the archive; the file nrao-fits.src is available at ftp://fits.cv.nrao.edu/fits/wais-sources/nrao-fits.src. Some of the more noteworthy materials in this archive are o Text of any detailed proposals currently being discussed by the FITS committees o Drafts of other formally proposed additions to the FITS standard and of potential future proposals o A collection of documents on World Coordinate Systems, including the current draft proposal o Conventions specific to particular projects or disciplines o Software for various environments and Usenet postings about code o Sample data and special test files designed to measure the ability of a FITS reader to handle a wide variety of FITS files o Archives of traffic on FITS-related newsgroups and exploders A separate NRAO site, http://www.cv.nrao.edu/~bcotton/fitsview.html, provides information on the FITSview family of software packages for display of FITS images on Microsoft Windows 3.1 and Windows 95, Apple Macintosh, and Unix/X-Windows, with links to the software. It also links to a number of sources of astronomical FITS images. ------- HEASARC The NASA/Goddard High Energy Astrophysics Science Archive Research Center (HEASARC) Web server at http://heasarc.gsfc.nasa.gov/docs/heasarc/fits.html and the anonymous ftp access through ftp://heasarc.gsfc.nasa.gov/fits_info/ provide FITS material. HEASARC has developed the FITSIO package of software routines for easily reading and writing FITS files, with FORTRAN and C versions available, portable to a wide variety of machines. There are also the FTOOLS collection of software tools, the VERIFITS FITS conformance verifier, and the fv FITS file viewer and editor. HEASARC software is available directly through http://heasarc.gsfc.nasa.gov/docs/heasarc/tech_res_software.html or ftp://heasarc.gsfc.nasa.gov/fits_info/software/ . The HEASARC server also provides information from the HEASARC FITS Working Group, (HFWG) the internal legislative body on FITS-related matters within the Office of Guest Investigator Programs (OGIP) at NASA/GSFC, at http://heasarc.gsfc.nasa.gov/docs/heasarc/ofwg/ofwg_intro.html or at ftp://heasarc.gsfc.nasa.gov/fits_info/ in the directories ofwg_minutes and ofwg_recomm. The HFWG has developed a number of FITS conventions that are more specific than the requirements of the FITS standards. Proposed conventions are publicized to the FITS community as a whole, with the goal of collaborative development of a set of conventions that will be accepted throughout the community as well as within OGIP/HEASARC. ------- Direct questions about this posting to Barry M. Schlesinger Coordinator, FITS Support Office Electronic mail: fits at nssdca.gsfc.nasa.gov Telephone: +1-301-286-2899 The FITS Support Office is operated under the guidance of the NASA/GSFC Astrophysics Data Facility. From owner-fitsbits at marmoset.cv.nrao.edu Wed Jul 9 23:38:30 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id XAA16920; œWed, 9 Jul 1997 23:38:30 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id TAA16482; Wed, 9 Jul 1997 19:25:44 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id TAA01592 for ; Wed, 9 Jul 1997 19:25:41 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id TAA13691; Wed, 9 Jul 1997 19:25:40 -0400 To: fitsbits at fits.cv.nrao.edu Date: 9 Jul 1997 22:05:34 GMT From: fitz at argus.lpl.arizona.edu (Mike Fitzgibbon) Message-ID: <5q11ve$f10$1 at news.ccit.arizona.edu> Organization: University of Arizona, LPL Path: newsfeed.cv.nrao.edu!hearst.acc.Virginia.EDU!uunet!in3.uu.net!144.212.100.12!news.mathworks.com!gatech!ennfs.eas.asu.edu!noao!math.arizona.edu!news.Arizona.EDU!not-for-mail References: <33C3457F.FCCFCF9C at bris.ac.uk> Subject: Re: Creating FITS files from 12 bit data from A/D converter.. Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk In article <33C3457F.FCCFCF9C at bris.ac.uk>, bsra at bris.ac.uk says... > >I'm attempting to convert 12 Bit data from my A/D converter into FITS >format for later use with AIPS... > >Can anyone point me in the right direction as to how to go about this? > >Many thanks, > >Dez Futak > >Co-ordinator of BSRA. > > This is rather a broad question. I am forwarding Barry Schlesinger's post on "Sources of FITS Information". This should get you started. Write back for any specific questions to be answered. Mike From owner-fitsbits at marmoset.cv.nrao.edu Thu Jul 10 14:08:20 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id OAA18860; œThu, 10 Jul 1997 14:08:20 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id OAA18845; Thu, 10 Jul 1997 14:05:54 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id OAA01819 for ; Thu, 10 Jul 1997 14:05:51 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id OAA04597; Thu, 10 Jul 1997 14:05:49 -0400 To: fitsbits at fits.cv.nrao.edu Date: 8 Jul 1997 16:16:47 GMT From: mschoell at eso.org (Markus Schoeller) Message-ID: <5ptp5f$ojt$1 at web3.hq.eso.org> Organization: ESO - European Southern Observatory, Garching by Munich Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!news-peer.sprintlink.net!news.sprintlink.net!Sprint!newsfeed.nacamar.de!Frankfurt.Germany.EU.net!Munich.Germany.EU.net!web3.hq.eso.org!mschoell Subject: Converting Matlab-Files to FITS Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Dear readers, does anyone know if a utility exists which converts Matlab-files (.MAT) into FITS format? Preferred platform is UNIX, if it runs under SunOS, the better. If this involves two programs, that's also OK. If there is nothing around, I will code this myself. So, if someone is interested in this, you can also contact me. Markus From owner-fitsbits at marmoset.cv.nrao.edu Thu Jul 10 23:40:20 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id XAA19962; œThu, 10 Jul 1997 23:40:20 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id VAA19638; Thu, 10 Jul 1997 21:15:42 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id VAA04608 for ; Thu, 10 Jul 1997 21:15:39 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id VAA21874; Thu, 10 Jul 1997 21:15:38 -0400 To: fitsbits at fits.cv.nrao.edu Date: Thu, 10 Jul 1997 17:49:53 -0700 From: Philip Scherrer Message-ID: <33C58331.41C6 at phil.stanford.edu> Organization: Stanford University Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!cpk-news-hub1.bbnplanet.com!su-news-hub1.bbnplanet.com!news.bbnplanet.com!news.Stanford.EDU!nntp.Stanford.EDU!not-for-mail References: <5ptp5f$ojt$1 at web3.hq.eso.org> Subject: Re: Converting Matlab-Files to FITS Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Markus Schoeller wrote: > > Dear readers, > > does anyone know if a utility exists which converts Matlab-files > (.MAT) into FITS format? Preferred platform is UNIX, if it runs > under SunOS, the better. If this involves two programs, that's > also OK. If there is nothing around, I will code this myself. So, > if someone is interested in this, you can also contact me. > > Markus I came across the following a few minutes after I saw your message. Thanks to AltaVista: http://tyche.mat.univie.ac.at/~rauth/matnews/FITS.image.format.x.html From owner-fitsbits at marmoset.cv.nrao.edu Mon Jul 14 11:25:46 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id LAA29933; œMon, 14 Jul 1997 11:25:46 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id LAA29911; Mon, 14 Jul 1997 11:20:20 -0400 Received: from palantir.cv.nrao.edu (tismail at palantir.cv.nrao.edu [192.33.115.254]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id LAA09779 for ; Mon, 14 Jul 1997 11:20:17 -0400 (EDT) Received: (from tismail at localhost) by palantir.cv.nrao.edu (8.8.5/8.8.5) id LAA29759 for ; Mon, 14 Jul 1997 11:26:53 -0400 Received: from wheelo.gsfc.nasa.gov(128.183.50.20) by palantir.cv.nrao.edu via smap (V1.3) id sma029757; Mon Jul 14 11:26:25 1997 Received: from tetra.gsfc.nasa.gov (tetra.gsfc.nasa.gov [128.183.127.109]) by wheelo.gsfc.nasa.gov (8.8.5/8.8.4) with SMTP id LAA29964 for ; Mon, 14 Jul 1997 11:19:17 -0400 (EDT) Received: by tetra.gsfc.nasa.gov (SMI-8.6/SMI-SVR4) id LAA02247; Mon, 14 Jul 1997 11:19:16 -0400 Date: Mon, 14 Jul 1997 11:19:16 -0400 From: pence at tetra.gsfc.nasa.gov (William Pence) Message-Id: <199707141519.LAA02247 at tetra.gsfc.nasa.gov> To: fitsbits at fits.cv.nrao.edu Subject: keyword units Cc: pence at tetra.gsfc.nasa.gov X-Sun-Charset: US-ASCII Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk The following convention for encoding the physical units of FITS keyword values was recently developed during discussions about the data products for some future missions. We would appreciate any comments about this proposal or on any other conventions that may already exist for encoding keyword units. Two routines for reading or writing keyword units using this convention have already been implemented in the latest version of the CFITSIO library (V1.25) on a trial basis. Assuming that the response is favorable, a corresponding pair of subroutines will be added in the next release of the Fortran FITSIO library. ----------------------------------------------------------------------- Proposed Convention for FITS Keyword Units William Pence (HEASARC) Jonathan McDowell (ASC) Clive Page (Leicester) 14 July 1997 One deficiency of the current FITS Standard is that it does not define a specific convention for recording the physical units of a keyword value. The TUNITn keyword can be used to specify the physical units of the values in a table column, but there is no comparable convention for keyword values. The comment field of the keyword is often used for this purpose, but the units are usually not specified in a well defined format that FITS readers can easily recognize and extract. To solve this deficiency, we propose a convention in which the keyword units are enclosed in square brackets as the first token in the keyword comment field; more specifically, the opening square bracket should immediately follow the slash '/' comment field delimiter and a single space character. The following examples illustrate keywords that use this convention: 1234567890123456789012345678901234567890123456789012345678901234567890123456789 EXPOSURE= 1800.0 / [s] elapsed exposure time V_HELIO = 16.23 / [km s**(-1)] heliocentric velocity LAMBDA = 5400. / [angstrom] central wavelength FLUX = 4.9033487787637465E-30 / [J/cm**2/s] average flux In general, the units named in the IAU(1988) Style Guide are recommended, with the main exception that the preferred unit for angle is 'deg' for degrees. This convention is optional and does not preclude other conventions. ----------------------------------------------------------------------- From owner-fitsbits at marmoset.cv.nrao.edu Mon Jul 14 23:21:31 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id XAA31510; œMon, 14 Jul 1997 23:21:31 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id WAA31445; Mon, 14 Jul 1997 22:47:55 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id WAA14633 for ; Mon, 14 Jul 1997 22:47:52 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id WAA03138; Mon, 14 Jul 1997 22:47:51 -0400 To: fitsbits at fits.cv.nrao.edu Date: Mon, 14 Jul 1997 22:32:58 -0400 From: Peter Teuben Message-ID: <33CAE15A.FD205043 at astro.umd.edu> Organization: University of Maryland Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!europa.clark.net!news.msfc.nasa.gov!info.usuhs.mil!cs.umd.edu!hecate.umd.edu!not-for-mail References: <199707141519.LAA02247 at tetra.gsfc.nasa.gov> Subject: Re: keyword units Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk William Pence wrote: > > The following convention for encoding the physical units of FITS > keyword values was recently developed during discussions about the data > products for some future missions. We would appreciate any comments > about this proposal or on any other conventions that may already exist > for encoding keyword units. > > Two routines for reading or writing keyword units using this > convention have already been implemented in the latest version of the > CFITSIO library (V1.25) on a trial basis. Assuming that the response > is favorable, a corresponding pair of subroutines will be added in the > next release of the Fortran FITSIO library. > > ----------------------------------------------------------------------- > > Proposed Convention for FITS Keyword Units > > William Pence (HEASARC) > Jonathan McDowell (ASC) > Clive Page (Leicester) > > 14 July 1997 > > One deficiency of the current FITS Standard is that it does not define > a specific convention for recording the physical units of a keyword > value. The TUNITn keyword can be used to specify the physical units of > the values in a table column, but there is no comparable convention for > keyword values. The comment field of the keyword is often used for > this purpose, but the units are usually not specified in a well defined > format that FITS readers can easily recognize and extract. > > To solve this deficiency, we propose a convention in which the keyword > units are enclosed in square brackets as the first token in the keyword > comment field; more specifically, the opening square bracket should > immediately follow the slash '/' comment field delimiter and a single > space character. The following examples illustrate keywords that use > this convention: > > 1234567890123456789012345678901234567890123456789012345678901234567890123456789 > EXPOSURE= 1800.0 / [s] elapsed exposure time > V_HELIO = 16.23 / [km s**(-1)] heliocentric velocity > LAMBDA = 5400. / [angstrom] central wavelength > FLUX = 4.9033487787637465E-30 / [J/cm**2/s] average flux > > In general, the units named in the IAU(1988) Style Guide are > recommended, with the main exception that the preferred unit for angle > is 'deg' for degrees. > > This convention is optional and does not preclude other conventions. > Novel idea! Comments/wonderings: 1) Would it not be useful to add a keyword to "version" this convention. In case it ever gets upgraded/modified? Should it also not be a comment? But it could also be a real keyword, in which case CFITSIO and others can more easily make (ab)use of it. 2) What kind of convention is used for the convention of how to "express" the formulae of the units? It sounds like you are using a fortran convention (** for power), but with a blank for multiplication. Can the notation be rigourously written down or is there room for confusion? [sorry, I still don't have my copy of the IAU style guide, and the answer may be in that. Isn't there a web page on this by now?] 3) what is the convention when something is e.g. log(flux), is it [log(J/cm**2/s)] where we all understand this is 10-based log, and not something else? - peter From owner-fitsbits at marmoset.cv.nrao.edu Tue Jul 15 09:23:04 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id JAA00141; œTue, 15 Jul 1997 09:23:04 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id FAA32532; Tue, 15 Jul 1997 05:43:43 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id FAA17540 for ; Tue, 15 Jul 1997 05:43:39 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id FAA22041; Tue, 15 Jul 1997 05:43:37 -0400 To: fitsbits at fits.cv.nrao.edu Date: Tue, 15 Jul 1997 10:37:29 +0100 From: Peter Bunclark Message-ID: <33CB44D8.225D at ast.cam.ac.uk> Organization: Royal Greenwich Observatory Path: newsfeed.cv.nrao.edu!hearst.acc.Virginia.EDU!uunet!in1.uu.net!160.45.4.4!fu-berlin.de!newsfeed.nacamar.de!feed.news.xara.net!xara.net!azure.xara.net!xara.net!server6.netnews.ja.net!server1.netnews.ja.net!lyra.csx.cam.ac.uk!news References: <199707141519.LAA02247 at tetra.gsfc.nasa.gov> Subject: Re: keyword units Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk One of the heated internal debates we had recently at the RGO was about whether keyword units should be SI units; we ended up putting the telescope focus in metres, whereas mm is far more natural. A general point is, I think referring to the IAU style-guide is a `cop out', having read the FITS Users Guide I did just that, and the style guide is targeted at something completely different, ie published papers. A machine-readable standard has to be far tighter. In the example I just mentioned of telescope focus, SI units are pretty silly in fact, so I would welcome an official blessing on being able to use `engineering units'. William Pence wrote: > > 1234567890123456789012345678901234567890123456789012345678901234567890123456789 > EXPOSURE= 1800.0 / [s] elapsed exposure time > V_HELIO = 16.23 / [km s**(-1)] heliocentric velocity > LAMBDA = 5400. / [angstrom] central wavelength > FLUX = 4.9033487787637465E-30 / [J/cm**2/s] average flux > There should be a table of combination units, eg [km s**(-1)], which have to be strictly adhered to to make parsing easy. So if your velocity is standard, then your FLUX would have to be in units of [J cm**(-2) s**(-1)] And finally, I leave you with this thought: DATE-OBS= 1997-07-15 / [UTC] today's date. Peter. From owner-fitsbits at marmoset.cv.nrao.edu Tue Jul 15 13:31:34 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id NAA00701; œTue, 15 Jul 1997 13:31:34 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id MAA00611; Tue, 15 Jul 1997 12:41:54 -0400 Received: from palantir.cv.nrao.edu (tismail at palantir.cv.nrao.edu [192.33.115.254]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id MAA20307 for ; Tue, 15 Jul 1997 12:41:51 -0400 (EDT) Received: (from tismail at localhost) by palantir.cv.nrao.edu (8.8.5/8.8.5) id MAA08451 for ; Tue, 15 Jul 1997 12:48:32 -0400 Received: from wheelo.gsfc.nasa.gov(128.183.50.20) by palantir.cv.nrao.edu via smap (V1.3) id sma008447; Tue Jul 15 12:48:03 1997 Received: from tetra.gsfc.nasa.gov (tetra.gsfc.nasa.gov [128.183.127.109]) by wheelo.gsfc.nasa.gov (8.8.5/8.8.4) with SMTP id MAA18118 for ; Tue, 15 Jul 1997 12:25:15 -0400 (EDT) Received: by tetra.gsfc.nasa.gov (SMI-8.6/SMI-SVR4) id MAA03417; Tue, 15 Jul 1997 12:25:10 -0400 Date: Tue, 15 Jul 1997 12:25:10 -0400 From: pence at tetra.gsfc.nasa.gov (William Pence) Message-Id: <199707151625.MAA03417 at tetra.gsfc.nasa.gov> To: fitsbits at fits.cv.nrao.edu Subject: Re: keyword units Cc: pence at tetra.gsfc.nasa.gov X-Sun-Charset: US-ASCII Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Regarding the recently proposed convention for keyword units, Peter Teuben wrote: > 1) Would it not be useful to add a keyword to "version" this > convention. In case it ever gets upgraded/modified? > Should it also not be a comment? But it could also > be a real keyword, in which case CFITSIO and others > can more easily make (ab)use of it. > One problem with a "version" keyword is that there is no rule requiring all the keywords in a header to use the same convention. In cases were keywords are copied from one file to another, one could end up with headers whose keywords use a mixture of conventions for encoding the units string thus making a version keyword meaningless. Both Peter Teuben and Peter Bunclark also commented on the units strings themselves, and questioned whether SI units should be strictly enforced, and whether there should be formal rules for constructing compound units (such as [m/s] vs. [m s**(-1)] ). Strictly speaking, these questions are beyond the scope of the currently proposed convention, in which we are simply proposing that the units string, in whatever units or format, is enclosed in square brackets as the first token of the comment field. But in answer to these types of questions, several years ago the HEASARC (also know as OGIP) FITS Working Group adopted some conventions for specifying physical units that are documented in a memo that is available on the Web at legacy.gsfc.nasa.gov/docs/heasarc/ofwg/docs/summary/ogip_93_001_summary.html This memo attempts to offer a compromise in line with the IAU recommendations, but also allows units that are especially convenient in astronomical applications such as deg, angstron, yr, arcsec, and arcmin. Prefixes (generally in powers of 3) are allowed as in: mm (millimeter), km (kilometer), Mm (Megameter), and even Ym (yottameter = 10**24 meters). Finally, rules for constructing compound units are discussed, including complicated expressions involving mathematical operations like log, ln, or sin. Fortunately, these complicated cases are rarely used, if at all. The topic of units strings is probably too controversial for this memo to be adopted as a standard, but still it should serve as a useful starting point for other groups who are trying to establish standard conventions for unit strings. -Bill Pence From owner-fitsbits at marmoset.cv.nrao.edu Thu Jul 17 16:53:02 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id QAA07457; œThu, 17 Jul 1997 16:53:02 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id QAA07442; Thu, 17 Jul 1997 16:51:44 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id QAA12397 for ; Thu, 17 Jul 1997 16:51:41 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id QAA09782; Thu, 17 Jul 1997 16:51:40 -0400 To: fitsbits at fits.cv.nrao.edu Date: Wed, 16 Jul 1997 11:05:15 -0700 From: Adriano Message-ID: <5qlumv$edp at news.vcnet.com> Organization: Internet Access of Ventura County 805.383.3500 Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!news.mathworks.com!uunet!in4.uu.net!205.231.12.3!news.vcnet.com!news Subject: Any .TIF to .FTS utilities?? Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Looking for a .TIF to .FTS conversion utility if any exists. Also, it needs to work on a PC with Windows95. Am I asking too much? Or have I been looking in the wrong places? If there are no .TIF to .FTS, how about .GIF, .BMP, .EPS, or other common graphics format to .FTS? Thanks for the help. -- _____ .___ .__ / _ \ __| _/______|__|____ ____ ____ / /_\ \ / __ |\_ __ \ \__ \ / \ / _ \ / | \/ /_/ | | | \/ |/ __ \| | ( <_> ) \____|__ /\____ | |__| |__(____ /___| /\____/ \/ \/ \/ \/ http://www.edmar-co.com/adriano/ Listen to RealAudio clips from my album "Virtual Landscapes": http://www.edmar-co.com/adriano/vl.shtml REMOVE *FOILER* to reply From owner-fitsbits at marmoset.cv.nrao.edu Sun Jul 20 22:09:47 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id WAA16579; œSun, 20 Jul 1997 22:09:47 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id IAA15226; Sun, 20 Jul 1997 08:13:27 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id IAA15667 for ; Sun, 20 Jul 1997 08:13:23 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id IAA06213; Sun, 20 Jul 1997 08:13:21 -0400 To: fitsbits at fits.cv.nrao.edu Date: Sun, 20 Jul 1997 14:05:05 +0200 From: "Venno G.J.S. Cladder" Message-ID: <33D1FEF1.3ED1 at introweb.nl> Organization: Cladder Computer Service & Euregio Publiekscentrum voor Sterrenkunde Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!EU.net!sun4nl!sun4nl!Utrecht.NL.net!Eindhoven.NL.net!not-for-mail References: <5qlumv$edp at news.vcnet.com> Reply-To: V.Cladder at net.HCC.nl Subject: Re: Any .TIF to .FTS utilities?? Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Hi! Adriano wrote: > Looking for a .TIF to .FTS conversion utility if any exists. Also, it > needs to work on a PC with Windows95. Am I asking too much? Or have I > been looking in the wrong places? If there are no .TIF to .FTS, how > about .GIF, .BMP, .EPS, or other common graphics format to .FTS? Most useful I found, as I told others before to use Graphic Workshop for Windows. Look at http://www.mindworkshop.com Bye, VC From owner-fitsbits at marmoset.cv.nrao.edu Wed Jul 23 10:48:44 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id KAA24826; œWed, 23 Jul 1997 10:48:44 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id KAA24811; Wed, 23 Jul 1997 10:47:53 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id KAA06850 for ; Wed, 23 Jul 1997 10:47:50 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id KAA20997; Wed, 23 Jul 1997 10:47:48 -0400 To: fitsbits at fits.cv.nrao.edu Date: 23 Jul 1997 14:47:44 GMT From: dwells at nrao.edu (Don Wells) Message-ID: Organization: nrao Path: newsfeed.cv.nrao.edu!newsfeed.cv.nrao.edu!dwells Subject: The Year-2000 DATExxxx Proposal Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Dear friends of FITS, I append the most recent draft of the year-2000 proposal. This version of the text has received unanimous approval by all three regional FITS committees (European FITS Committee, WGAS [North American] FITS Committee, Japanese FITS Committee). I have therefore submitted it to the IAU FITS Working Group [IAU-FWG] for consideration as an addition to the FITS agreements/standards. Please examine this proposal and post suggested modifications to sci.astro.fits/fitsbits (or send them privately to me at ) before 1997-07-30 (one week from today), when I expect to issue the call-for-votes to the IAU-FWG. I am aware of one large data analysis software package which has already made the necessary code changes to implement this proposed agreement. I would like to be told of other implementations. Regards, Don Wells (Chair, IAU FITS Working Group) ------- start of forwarded message (RFC 934 encapsulation) ------- From: Arnold Rots Sender: owner-wfc at marmoset.cv.nrao.edu To: wfc at cv3.cv.nrao.edu Subject: Year 2000 Proposal Date: Thu, 3 Jul 1997 17:07:26 -0400 (EDT) This file contains a proposal for how to revise the definition of the DATExxxx keywords to provide a 4-digit year. It has been developed as a distillation of discussion on the sci.astro.fits newsgroup, electronic mail interchanges, discussion with Preben Grosbol, and discussions within the WGAS (North American) FITS Committee [WFC]. The previous version of the proposal was submitted to the FITS committees by Peter Bunclark of the Royal Greenwich Observatory, and was endorsed by the European FITS Committee [EFC]. This newly amended version of the DATExxxx proposal is consistent with the Bunclark/EFC version, with the following exceptions, additions, and deletions: 1. The use of the UTC time scale is mandatory and implied for data that originated since 1972, unless an alternative, valid time scale is specified. UT is adopted as the pre-1972 equivalent of UTC. 2. The appendix suggests an implementation of the time scale specification. Time scales that will be initially recognized are: UTC, TAI, ET, TT, TDT, TDB, TCG, TCB. 3. Support for use of the "Z" qualifier is deleted since it would be either superfluous or create an inconsistency. 4. The default interpretation of all DATExxxx keywords shall use the Gregorian Calendar. 5. The ISO 8601 appendix is removed and all relevant information included in the body of the proposal. 6. The exception for 19th century plates is restricted to existing files. For a convenient summary of time scales, see: http://tycho.usno.navy.mil/systime.html To summarize our concerns: a. UTC is not defined before 1972. b. FITS files should, internally, not mix time scales; there are files around that use TT, TDB, TAI, in addition to UTC. c. Not all code needs to know about all time scales; in almost all cases it would not hurt if UTC were assumed. I would suggest that WFC forward this proposal to the IAU FITS Working Group. - Arnold - --------------------------------%<---------------------------------------- Precise re-definition of DATE-OBS Keyword encompassing the millennium Peter Bunclark 1996 Nov 19 Amended: Arnold Rots 1997-06-27 1) Introduction Although this document formally defines the format of the value field of the DATE-OBS keyword, the same format is recommended for all other keywords specifying date and time which we shall refer to collectively as DATExxxx. The original DATExxxx keywords, including in particular DATE-OBS, have several shortcomings which make it desirable to alter the definition: 1.1) The year is expressed in only 2-digits; currently, digitized astronomical data spans more than a century, and further, the implied most-significant two digits of the year will change from 19 to 20 shortly. 1.2) The timescale of DATExxxx is not defined. 1.3) The relation of DATE-OBS to the start, middle or end of an observation is not defined. 1.4) The order of day, month, year is least-significant first, so lists of dates cannot be sorted simply on the ASCII collating sequence. 2) Scope There are three main issues addressed; 2.1) the format of date strings to be used in any DATExxxx keyword. 2.2) the future of the DATE-OBS keyword itself 2.3) the specification of the time scales (time systems) used 3) The Date-String format Proposal 3.1) A DATExxxx field in the old format of 'DD/MM/YY' will explicitly refer to a year 1900-1999. The very few instances of digitized nineteenth-century plates represented as FITS files (only files created before this proposal went into effect) must be handled as special cases. 3.2) The new recommended format is a restricted subset of ISO-8601, being one of two options: a) 'CCYY-MM-DD' b) 'CCYY-MM-DDThh:mm:ss[.sss...]' represents a calendar year, the ordinal number of a calendar month within the calendar year, and
the ordinal number of a day within the calendar month. represents the hour in the day, the minutes, the seconds. The literal 'T' is the ISO 8601 time designator. In the short form, there may not be any additional terminator/separator (such as T). In the long form, there must be a 'T' time designator between the date and the time. The decimal point character is an ASCII full-stop (hexadecimal value 0x2E). The number of decimal places in the `seconds' field may be arbitrarily long, up to the FITS header-card limitations. 3.3) Only fully-specified date or date/time strings are permitted. No fields may be defaulted, no leading zeroes omitted. The decimal part of the seconds field is optional. 4) Use of the DATE-OBS keyword 4.1) The name of the keyword shall remain DATE-OBS. 4.2) It is suggested that the DATE-OBS refer to the start of an observation. This relationship should be clarified in the comment field. 4.3) The default interpretation of all DATExxxx keywords shall use the Gregorian Calendar for the date portion. 4.4) The value of the DATExxxx keywords shall be expressed in the principal time scale or time system of the HDU to which they belong. The default interpretation shall use UTC (for dates since 1972) or UT (for dates before 1972). 4.5) It is recommended that the time scale or time system be specified explicitly. However, the error resulting from ignoring the time scale specification and making the default assumption, will not exceed 1000 s for the period 1001-01-01 through 3000-12-31. 5) Examples Three legal representations of the date of the first formal draft of this proposal are possible: DATE-OBS= '14/10/96' / Original format, means 1996 Oct 14. DATE-OBS= '1996-10-14' / Date of start of observation, by default UTC. DATE-OBS= '1996-10-14T10:14:36.123' / Date and time of start of obs. in UTC. 6) Transition FITS readers must continue to interpret the old format, as a twentieth century date, forever. Readers should be altered as soon as possible to cope with the new format. In order to give adequate time for the major package writers to revise their software, FITS writers should commence writing the new format between 1998-01-01T00:00:00 and 2000-01-01T00:00:00. 7) Appendix: Suggested time scale specification [Note: this appendix is not part of the formal DATExxxx agreement] 7.1) Use of the keyword TIMESYS is suggested as an implementation of the time scale specification; it is currently in use as such in the RXTE mission archive. It sets the dominant time system for time-related keywords and data in the HDU (i.e., it does not preclude the addition of keywords or data columns that provide information for transformations to other time scales, such as sidereal times or barycenter corrections). Initially, officially allowed values are: UTC Coordinated Universal Time; defined since 1972. UT Universal Time, equal to Greenwich Mean Time (GMT) since 1925; the UTC equivalent before 1972; see: Explanatory Supplement, p. 76. TAI International Atomic Time; "UTC without the leap seconds"; 31 s ahead of UTC on 1997-07-01. IAT International Atomic Time; deprecated synonym of TAI. ET Ephemeris Time, the predecessor of TT; valid until 1984. TT Terrestrial Time, the IAU standard time scale since 1984; continuous with ET and synchronous with (32.184 s ahead of) TAI. TDT Terrestrial Dynamical Time; =TT. TDB Barycentric Dynamical Time. TCG Geocentric Coordinate Time; runs ahead of TT since 1977-01-01 at a rate of approximately 22 ms/year. TCB Barycentric Coordinate Time; runs ahead of TDB since 1977-01-01 at a rate of approximately 0.5 s/year. For reference, see: Explanatory Supplement to the Astronomical Almanac, P. K. Seidelmann, ed., University Science Books, 1992, ISBN 0-935702-68-7. Use of GPS time (19 s behind TAI) is deprecated. 7.2) Times will be deemed to be as measured at the detector (or in practical cases, at the observatory) unless a different location is implied by the time system specified. This is the case for coordinate times (such as TCG and TCB) and TDB which are tied to an unambiguous coordinate origin In those cases the meaning of time values will be: time as if the observation had taken place at the origin of the coordinate time system. This implies that path length differences have been corrected for. Note that the difference TDB-UTC is approximately sinusoidal, with period one year and amplitude up to 500 s, depending on source position. Also, note that when the location is not unambiguous (such as in the case of an interferometer) precise specification of the location is strongly encouraged in, for instance, geocentric Cartesian coordinates. 7.3) Note that "TT" is the IAU preferred standard. It may be considered equivalent to "TDT" and "ET", though "ET" should not be used for data taken after 1984. For reference, see: Explanatory Supplement, pp. 40-48. 7.4) If the TIMESYS keyword is absent or has an unrecognized value, the value "UTC" will be assumed for dates since 1972, and "UT" for pre-1972 data. 7.5) Examples The three legal representations of the date of the first formal draft of this proposal would become: DATE-OBS= '14/10/96' / Original format, means 1996 Oct 14. TIMESYS = 'UTC ' / Explicit time scale specification: UTC. DATE-OBS= '1996-10-14' / Date of start of observation in UTC. DATE-OBS= '1996-10-14' / Date of start of observation, also in UTC. TIMESYS = 'TT ' / Explicit time scale specification: TT. DATE-OBS= '1996-10-14T10:14:36.123' / Date and time of start of obs. in TT. 7.6) The convention suggested in this Appendix is part of the mission-specific FITS conventions adopted for, and used in, the RXTE archive, building on existing High Energy Astrophysics FITS conventions. See: http://legacy.gsfc.nasa.gov/docs/xte/abc/time_tutorial.html http://heasarc.gsfc.nasa.gov/docs/xte/abc/time.html The VLBA project has adopted a convention where the keyword TIMSYS, rather than TIMESYS, is used, currently allowing the values UTC and IAT. See p.9 and p.16 of: http://www.cv.nrao.edu/fits/documents/drafts/vlba_format.ps ------- end ------- -- Donald C. Wells Associate Scientist dwells at nrao.edu http://fits.cv.nrao.edu/~dwells National Radio Astronomy Observatory +1-804-296-0277 520 Edgemont Road, Charlottesville, Virginia 22903-2475 USA From owner-fitsbits at marmoset.cv.nrao.edu Fri Jul 25 11:49:13 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id LAA31283; œFri, 25 Jul 1997 11:49:13 -0400 Received: from fits.cv.nrao.edu (dwells at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id LAA31256; Fri, 25 Jul 1997 11:47:58 -0400 Received: (from dwells at localhost) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) id LAA12284; Fri, 25 Jul 1997 11:47:55 -0400 (EDT) Date: Fri, 25 Jul 1997 11:47:55 -0400 (EDT) From: Don Wells Message-Id: <199707251547.LAA12284 at fits.cv.nrao.edu> To: fitsbits at fits.cv.nrao.edu, iaufwg at fits.cv.nrao.edu Subject: Interoperability trials of DATExxxx='yyyy-mm-dd' Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk Dear IAU FITS Working Group and other friends of FITS, As Preben Grosbol (former Chair of IAU-FWG) has pointed out, it has been and still is an IAU-FWG rule that proposed additions to the FITS standards must be tested in two-way interoperability trials involving at least two independent implementations. The purpose of this rule is to assure that at least two independent implementors care enough about any proposed addition to actually code support for it and that their readings of the text of the proposed agreement are consistent. Such testing also reduces the likelihood that there are hidden flaws in proposed FITS agreements. The proposed year-2000 agreement needs to be tested as soon as possible. I know of two major astronomy data analysis systems which have already been modified to read DATExxxx='yyyy-mm-dd' as well as 'dd/mm/yy'. One of these systems has also been modified to write the new date format beginning 1998-01-01. Private discussions are underway between the developers of these two systems to exchange test files which could be read by the two systems. The first such sample FITS file for interoperability testing is available via anonymous-FTP (the 'newdate.lst' file contains an ASCII listing of the header): ftp://fits.cv.nrao.edu/fits/data/samples/year-2000/newdate.fits.gz ftp://fits.cv.nrao.edu/fits/data/samples/year-2000/newdate.lst This FITS file contains three DATExxxx keywords in the new style: DATE-OBS= '1979-09-19' /OBSERVATION START DATE DD/MM/YY DATE-MAP= '1992-09-18' /DATE OF LAST PROCESSING DD/MM/YY DATE = '1997-07-25' / File written on yyyy-mm-dd I will be pleased to receive other sample FITS files containing DATExxxx values in the new style, and will place them in the same anonymous-FTP directory. I encourage other developers to modify their software systems to either read or write the new style, and to join in the interoperability trials. Regards, Don Wells (Chair, IAU FITS Working Group) -- Donald C. Wells Associate Scientist dwells at nrao.edu http://fits.cv.nrao.edu/~dwells National Radio Astronomy Observatory +1-804-296-0277 520 Edgemont Road, Charlottesville, Virginia 22903-2475 USA From owner-fitsbits at marmoset.cv.nrao.edu Mon Jul 28 08:59:00 1997 Received: (from majdom at localhost) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) id IAA06526; œMon, 28 Jul 1997 08:59:00 -0400 Received: from fits.cv.nrao.edu (root at fits.cv.nrao.edu [192.33.115.8]) by marmoset.cv.nrao.edu (8.8.5/8.8.5: $Revision: 2.2 $) with ESMTP id EAA06080; Mon, 28 Jul 1997 04:24:07 -0400 Received: from newsfeed.cv.nrao.edu (newsfeed.cv.nrao.edu [192.33.115.17]) by fits.cv.nrao.edu (8.8.5/8.8.0/CV-2.2) with ESMTP id EAA00641 for ; Mon, 28 Jul 1997 04:24:03 -0400 (EDT) Received: (from news at localhost) by newsfeed.cv.nrao.edu (8.8.5/8.8.5) id EAA03985; Mon, 28 Jul 1997 04:24:02 -0400 To: fitsbits at fits.cv.nrao.edu Date: Mon, 28 Jul 1997 10:14:44 +0200 From: Lucio Chiappetti Message-ID: Organization: Consiglio Nazionale delle Ricerche Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!EU.net!blackbush.xlink.net!news-ge.switch.ch!serra.unipi.it!newsserver.cilea.it!leonardo.area.mi.cnr.it!poseidon.ifctr.mi.cnr.it!lucio References: <199707141519.LAA02247 at tetra.gsfc.nasa.gov> <33CB44D8.225D at ast.cam.ac.uk> Subject: Re: keyword units Newsgroups: sci.astro.fits Sender: owner-fitsbits at marmoset.cv.nrao.edu Precedence: bulk On Tue, 15 Jul 1997, Peter Bunclark wrote: > One of the heated internal debates we had recently at the RGO was about > whether keyword units should be SI units; we ended up putting the telescope > focus in metres, whereas mm is far more natural. Uh ? Aren't all decimal divider and multiplier prefixes (milli micro kilo mega etc.) part of SI *AS WELL AS* the "main" units ? Thus "feet" or "parsecs" would not be SI, but m, km, mm etc, will ! ---------------------------------------------------------------------------- Lucio Chiappetti - IFCTR/CNR - via Bassini 15 - I-20133 Milano (Italy) For more info : http://www.ifctr.mi.cnr.it/~lucio/personal.html ----------------------------------------------------------------------------