NOTICE TO USERS
Commander, Naval Meteorology and Oceanography Command is consolidating the command's web presence in accordance with Department of Defense (DoD) and Navy guidance. The U.S. Naval Oceanography portal will be the single access point for all public facing Meteorology and Oceanography products and services. This publicly-accessible portal is currently online at http://www.usno.navy.mil and is being populated. In the near future, non-DoD users will be redirected to this portal.
DoD customers can access all operational data, products and services via the NIPRnet Naval Oceanography Portal site at https://oceanography.navy.mil (CAC required).
NOVAS version F3.0g (beta) of 2008
The 2008 version of the Naval Observatory Vector Astrometry Subroutines (NOVAS) implements the resolutions on astronomical reference systems and Earth rotation models passed at the IAU General Assemblies in 1997, 2000, and 2006. Compared with NOVAS version 2.0 of 1998, this version also improves the accuracy of NOVAS' star and planet position calculations (apparent places) by including several small effects not previously implemented in the code. A number of new convenience functions have also been added.
NOVAS version F3.0g is the fourth public release of the new version of NOVAS. It is a beta test version, which means that some bugs may remain. It has been quite thoroughly tested, however, so that remaining bugs, if any, are likely to produce only low-level effects or reside in infrequently used functions. If further corrections or updates need to be made to the package, the letter suffix, now "g", will be changed to "h", "i", etc. Such changes will be outlined in another file, and if you download and use any of the version F3.0 releases, it would be a good idea to check back every so often to see if anything has changed.
This version of NOVAS is currently implemented only in Fortran. The update to the C version is nearing completion and should be available during the summer of 2008.
If you are not already a NOVAS user, you should probably start by looking at the documentation on the existing standard version, NOVAS version 2.0 of 1998. As much as possible, the old subroutine calls described there have been maintained. Version F3.0 provides a lot of new functionality, but it is generally provided by new calls.
NOVAS requires access to the JPL planetary and lunar ephemeris DE405. The JPL ephemerides and the software to access them can be obtained on CD-ROM from Willman-Bell, Inc., or downloaded from the JPL web site.
At this point, documentation specific to version F3.0 is limited to an overview file that describes the changes made to NOVAS between 1998 and 2008 — that is, between versions F2.0 and F3.0. For people who have already been using version F2.9 (the "interim new version" introduced in 2004) there is a second file describing the changes made between that version and the most recent one. See the links below. (The final documentation for NOVAS version F3.0 is in preparation.) All of the NOVAS subroutines have preambles embedded in the source code that describe their purpose, the input and output arguments, and any usage notes.
Please report any bugs to George Kaplan at the Naval Observatory. Thanks!
Available files in this directory:
NOVAS_F3.0g.f NOVAS version F3.0g (Fortran source) 440 kb
NOVAS_F3.0g.f.gz gzipped version of above 71 kb
NOVAS_F3.0_Overview.pdf Overview of NOVAS version F3.0 (PDF)
NOVAS_F3.0_Changes.pdf List of changes from version F2.9 to F3.0 (PDF)
changes.php List of changes since initial public F3.0 release (release F3.0d of 1 Aug 06)
CIO_RA.TXT CIO right ascension as a function of time (ASCII, sequential) 7.1 Mb
CIO_RA.TXT.gz gzipped version of above 1.8 Mb
CIO_file.f Program to convert above file to binary direct-access (Fortran source)
