USNO A1.0 November 1996 USNO SA1.0 December 1996 This file is the first level of the on-board documentation. Please read this file first. Near the end of this file is a list of other files that might be helpful. Questions and comments should be directed to Dave Monet US Naval Observatory Flagstaff Station PO Box 1149 (US Mail Only) West Highway 66 (FedEx, UPS, etc.) Flagstaff AZ 86002 Voice: 520-779-5132 FAX: 520-774-3626 e-mail: email@example.com Please understand that the level of support provided will be commensurate with the level of effort expended. I am too busy to do your homework for you. E-mail works better than the phone. ============ Title ==================== USNO-A V1.0 A Catalog of Astrometric Standards David Monet a) Alan Bird a), Blaise Canzian b), Hugh Harris a), Neill Reid c), Albert Rhodes a), Stephen Sell a), Harold Ables d), Conard Dahn a), Harry Guetter a), Arne Henden b), Sandra Leggett e), Harold Levison f), Christian Luginbuhl a), Joan Martini a), Alice Monet a), Jeffrey Pier a), Betty Riepe a), Ronald Stone a), Frederick Vrba a), Richard Walker a) a) U.S. Naval Observatory Flagstaff Station (USNOFS) b) Universities Space Research Association (USRA) stationed at USNOFS c) Palomar Observatory, California Institute of Technology d) USNOFS, now retired e) USRA, now at University of Hawaii f) USRA, now at Planetary Science Institute, Boulder CO ============== Abstract ======================= USNO-A is a catalog of 488,006,860 sources whose positions can be used for astrometric references. These sources were detected by the Precision Measuring Machine (PMM) built and operated by the U. S. Naval Observatory Flagstaff Station during the scanning and processing of the Palomar Observatory Sky Survey I (POSS-I) O and E plates, the UK Science Research Council SRC-J survey plates, and the European Southern Observatory ESO-R survey plates. The PMM detects and processes at and beyond the nominal limiting magnitude of these surveys, but the large number of spurious detections requires that a filter be used to eliminate as many as possible. USNO-A's sole inclusion requirement was that there be spatially coincident detections (within a 2 arcsecond radius aperture) on the blue and red survey plate. For field centers of -30 degrees and above, data come from POSS-I plates, while data from field centers of -35 and below come from SRC-J and ESO-R plates. USNO-A presents right ascension and south polar distance in the system of J2000 at the epoch of the survey blue plate for each object, and lists an estimate of the blue and red magnitude. For POSS-I sources, the photometric system is the photographic system defined by the O and E emulsions and filters, while southern sources are measured in the photometric system defined by the IIIa-J and IIIa-F emulsions. It is believed that the typical astrometric error is about 0.25 arcseconds and that the typical photometric error is about 0.25 magnitudes. However, these error estimates are dominated by the systematic errors incorporated in the calibration procedure, and some fields may be significantly worse. Should users be willing to locally recalibrate the astrometry and photometry, the errors arising from the PMM are believed to be in the range of 0.15 arcsecond and 0.15 magnitude. To avoid the necessity of consulting many catalogs, objects brighter than 11th magnitude that appear in the Guide Star Catalog that were not detected by the PMM were inserted. USNO-A covers the entire sky, and goes as deep as O=21, E=20, J=22, and F=21 for objects with appropriate colors. The limiting magnitude is brighter for objects with extreme colors, and follows from the requirement for a detection on both the blue and red survey plate. Although it covers the entire sky, there are holes in the catalog in the vicinity of bright stars, regions of nebulosity, crowded fields, etc. ============== Statement of Intellectual Property Rights ==================== This catalog contains data from a diverse collection of photographs, reductions, and catalogs. A large number of different organizations claim copyright and/or intellectual property rights on the various components. Although the details differ, all permissions for usage of data are contingent on unrestricted access. Distribution and/or other direct costs can be recovered, but re-packaging, re-formatting, or similar activities, especially for commercial purposes, are not permitted except as authorized by the U. S. Naval Observatory in consultation with the other institutions listed below and as appropriate. 1) Palomar Observatory, National Geographic Society, and California Institute of Technology own Palomar Observatory Sky Surveys I and II. 2) European Southern Observatory owns the ESO-R survey. 3) The UK Particle Physics and Astronomy Research Council (formerly Science and Engineering Research Council and before that Science Research Council) owns the SRC-J survey. 4) Space Telescope Science Institute (and AURA and NASA) own the Guide Star Catalog. 5) US Naval Observatory owns the digitization of the plates and the object parameters and catalogs made from them. 6) The Anglo-Australian Telescope Board retains the copyright to plates taken with the U.K. Schmidt Telescope after 15 June 1988. In particular, we reserve the rights to compile and distribute zone catalogs, summary catalogs, or other significant pieces of USNO-A beyond that which is needed to support personal or institutional scientific or educational projects. Included in this is the preparation and distribution of images generated from the USNO-A catalog beyond those needed for finding charts and similar purposes. In summary, you are welcome to use the catalog, but significant redistribution, extraction, and image rights are reserved, and permission needs to be obtained before using this catalog for such purposes. Please don't make us wake up the lawyers. Please treat these data and catalogs in the spirit in which they were created. They are for non-profit educational and scientific pursuits, and not for third parties to remarket for a profit. =======================Request for Citations================================= It is an unfortunate aspect of modern funding that impersonal and statistical measures are used to assess the productivity and usefulness of programs. If you benefited from using USNO-A, we ask that you give the catalog a citation. By doing so, we may be able to justify the expense of continued production of catalogs. Whenever possible, it would be appropriate to note which survey (POSS-I, ESO, and/or SRC) supplied the relevant data, since these surveys are measured, in part, by the extent to which they serve the community. =======================How To Proceed==================================== There is no paper copy of this catalog. All documentation that exists has been put somewhere on the CD-ROM set. A reasonable strategy for learning about and using this catalog is the following. read.me - Contains a brief description and the necessary statement of intellectual property rights. read.use - Contains a description of the format of the various files and what they contain. A companion file, demo.tar, contains the source code for a simple program that uses this catalog. catalog.tar - contains the ASCII text files that describe each of the plates taken as part of the various surveys. Of particular interest is the epoch of each plate since proper motions have not been computed and applied to the position of each source. read.ast - Contains a description of the astrometric reduction procedure. read.pht - Contains a description of the photometric reduction procedure. read.pmm - Contains a description of the PMM hardware and software. sg1.tar - Contains the source code for all software needed to run the PMM and do the real time processing. Included in this file are the bias and flat field frames as well as the coefficients used in the geometric calibration procedure. binary.tar - Contains the source code for about half of the routines used to reduce the raw PMM data and produce this catalog. newbin.tar - Contains the source code for the rest of the routines used to reduce the raw PMM data and produce this catalog. ================Table of Contents===================== File CD-ROM ---------------------------------------------- zone0000.acc/.cat 1 zone0075.acc/.cat 1 zone0150.acc/.cat 6 zone0225.acc/.cat 5 zone0300.acc/.cat 3 zone0375.acc/.cat 2 zone0450.acc/.cat 1 zone0525.acc/.cat 4 zone0600.acc/.cat 6 zone0675.acc/.cat 5 zone0750.acc/.cat 7 zone0825.acc/.cat 10 zone0900.acc/.cat 8 zone0975.acc/.cat 7 zone1050.acc/.cat 8 zone1125.acc/.cat 9 zone1200.acc/.cat 9 zone1275.acc/.cat 4 zone1350.acc/.cat 10 zone1425.acc/.cat 3 zone1500.acc/.cat 2 zone1575.acc/.cat 6 zone1650.acc/.cat 2 zone1725.acc/.cat 3 .lut files for all zones 7 pmmgsc.len 7 read.me 1 read.ast 1 read.pht 1 read.pmm 1 read.use 1 demo.tar 1 catalog.tar 2 newbin.tar 6 binary.tar 8 sg1.tar 8 ================Other Notices===================== The source codes are the intellectual property of the U. S. Naval Observatory and are provided so that the expert user can answer detailed questions about how the catalog was constructed. Casual users should avoid them because they contain no instructions as to where various useful things are hidden. Release of the source code is made to support such investigations only, and is not intended for commercial or other non-professional applications. The source code is a protected property, and illegal usage is prohibited. If in doubt, please contact Dave Monet for clarifications and protections. The PMM program has been supported through internal funding by USNO, and by funding provided by the U. S. Air Force through the Space Surveillance Network Improvement Program. This work is based partly on photographic plates obtained at the Palomar Observatory 48-inch Oschin Telescope for the First and Second Palomar Observatory Sky Surveys which was funded by the Eastman Kodak Company, the National Geographic Society, the Samuel Oschin Foundation, the Alfred Sloan Foundation, the National Science Foundation grants AST84-08225, AST87-19465, AST90-23115 and AST93-18984, and the National Aeronautics and Space Administration grants NGL 05002140 and NAGW 1710. This catalog is based, in part, upon original material from the UK Schmidt Telescope, copyright in which is owned by the UK Particle Physics and Astronomy Research Council. No charge beyond recovery of costs has been made by USNO or PPARC for the provision of these data. These data are provided to its recipient for its purpose without restriction, except on the condition that the data should not be replicated, in whole or in part, and passed on for profit. The plates for the SRC-J survey were taken with the UK Schmidt Telescope (UKST). The copyright inherent in the plate material obtained with the UK Schmidt Telescope taken after 15 June, 1988 rests with the Anglo-Australian Telescope Board. The European Southern Observatory holds the copyright to the ESO-R Survey plate material, and USNO scanned these plates under an agreement with ESO. This agreement states, in part, that the data derived from these scans shall be available to the public without restriction and without charge beyond recovery of the cost of distribution. USNO would like to thank NOAO/KPNO for the permission to borrow the glass copies of the SRC and ESO surveys for scanning, and to Bill Schoening and Richard Green for their assistance.