From heafits@olegacy.gsfc.nasa.gov Tue Dec 2 14:57 EST 1997 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4278" "Tue" "2" "December" "1997" "14:54:45" "-0500" "Arnold Rots" "arots@xebec.gsfc.nasa.gov" "<199711251808.NAA05525@xebec.gsfc.nasa.gov>" "108" "JPL DE200 and DE405 in FITS; Barycenter Code" "^From:" nil nil "12" "1997120219:54:45" "JPL DE200 and DE405 in FITS; Barycenter Code" nil nil] nil) Received: from palantir.cv.nrao.edu (tismail@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 OAA11808 for ; Tue, 2 Dec 1997 14:57:44 -0500 (EST) Received: (from tismail@localhost) by palantir.cv.nrao.edu (8.8.5/8.8.5) id OAA31359 for ; Tue, 2 Dec 1997 14:57:42 -0500 Received: from olegacy-f.gsfc.nasa.gov(128.183.240.24) by palantir.cv.nrao.edu via smap (V1.3) id sma031357; Tue Dec 2 14:57:28 1997 Received: from olegacy.gsfc.nasa.gov (localhost [127.0.0.1]) by olegacy.gsfc.nasa.gov (8.7.5/8.7.3) with SMTP id OAA09992; Tue, 2 Dec 1997 14:54:45 -0500 (EST) Message-Id: <199711251808.NAA05525@xebec.gsfc.nasa.gov> Errors-To: dpf@egret.gsfc.nasa.gov Reply-To: heafits@olegacy.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0c -- ListProcessor by Anastasios Kotsikonas Content-Type: text Content-Length: 4277 From: Arnold Rots Sender: heafits@olegacy.gsfc.nasa.gov To: dwells@fits.cv.nrao.edu Subject: JPL DE200 and DE405 in FITS; Barycenter Code Date: Tue, 2 Dec 1997 14:54:45 -0500 (EST) This is the announcement of the release of a FITS version of the JPL DE200 and DE405 solar system ephemerides, and an ANSI-C software package to access these ephemerides and calculate barycenter corrections. The package was developed for the RXTE mission, but written in such a way that, where necssary, mission-dependent functions can be plugged in for other space missions, as well as for ground-based observatories. I would like to emphasize that the FITS versions contain the full DE ephemeris data (i.e., all planets) and use the original Chebyshev polynomials. This summer, the new JPL DE405 solar system ephemeris was released. That seemed a good reason to revamp XTE's barycenter correction code and make it fully generic. It would be good if the astronomical community were to switch over to DE405 and I hope that making this code available will further that cause. In order to distinguish which planetary ephemeris (if any) has been used to create a particular FITS file, I have adopted a convention using the existing FITS keyword RADECSYS and the new keyword PLEPHEM. DE200 is indicated by: RADECSYS= 'FK5' PLEPHEM = 'JPL-DE200' DE405 is indicated by: RADECSYS= 'ICRS' PLEPHEM = 'JPL-DE405' In addition, the TIMESYS keyword, as defined in the Appendix to the FITS Year-2000 resolution, is used. The package may be obtained from: ftp://heasarc.gsfc.nasa.gov/xte/calib_data/clock/bary This directory contains a 00README and a gzipped tar file. Appended below is the introduction of the 00README file. The package requires the HEASARC's cfitsio library. - Arnold Rots NASA/GSFC - USRA arots@xebec.gsfc.nasa.gov XTE-GOF Code 660.2 GSFC Greenbelt, MD 20771 -------------------------------------------------------------- BARY $Id: 00README,v 2.0 1997/11/25 14:56:24 arots Exp arots $ Arnold Rots USRA 25 November 1997 A package containing: - the JPL DE200 and DE405 ephemerides (full Chebyshev polynomials) in FITS format; - ANSI standard C code to access those ephemerides; - new barycenter correction code that can use either ephemeris and starts from any of these time systems: UTC, ET, TT, TCG, TAI; - a phase binner that bins photon events in absolute phase, using the Princeton radio pulsar database (format); - a utility, baryFase, that calculates barycenter corrections and (optionally) absolute phase for any time and celestial position. One should be aware that the JPL ephemeris, as distributed in "Unix" format, are really IEEE; hence, those files will work just fine on, say, a Sparc station, but will cause trouble on Alphas and Intel machines. The FITS format circumvents this problem. Although the application is for barycenter corrections, the dpleph version distributed as part of this package will allow retrieval of positions for all members of the solar system contained in the JPL DE ephemerides. The barycenter package is geared toward space missions and detects the identity of the mission through the TELESCOP or MISSION keywords in the FITS headers. However, it will be easy to include ground-based observatories by inserting an appropriate geographic position function for the "orbit ephemeris". Indeed, the currently supported "missions" are XTE and the Geocenter. This directory contains the following files: 00README This file JPLEPH.200 FITS version of the JPL DE200 lunar and planetary ephemeris for 1950-2050 JPLEPH.405 FITS version of the JPL DE405 lunar and planetary ephemeris for 1950-2050 JPLEPH Symbolic link to the default ephemeris dpleph.c Functions to access the JPL ephemeris bary.c General utilities and functions to calculate barycenter corrections ctatv.c Function to calculate TDB - TT baryFase.c Utility to calculate individual barycenter corrections and phase phaseHist.c Phase binner function: bins events in energy and absolute phase according to timing ephemeris faseBin.c The phase binner main function, or wrapper, for phaseHist bary.h Header file required by all xCC.c XTE clock correction function bineph2fits.c Utility to convert ephemerides to FITS