J/A+A/582/A36 USNO Martian observations (Robert+, 2015)
A new astrometric measurement and reduction of USNO photographic observations of
Phobos and Deimos: 1967-1997.
Robert V., Lainey V., Pascu D., Pasewaldt A., Arlot J.-E., De Cuyper J.-P.,
Dehant V., Thuillot W.
<Astron. Astrophys. 582, A36 (2015)>
=2015A&A...582A..36R 2015A&A...582A..36R (SIMBAD/NED BibCode)
ADC_Keywords: Planets ; Positional data
Keywords: astrometry - ephemerides -
planets and satellites: individual: Phobos -
planets and satellites: individual: Deimos
Abstract:
Accurate positional measurements of planets and satellites are used to
improve their orbits, our knowledge of their dynamics and to infer the
accuracy of the planet and satellite ephemerides. In the framework of
the European FP7 ESPaCE program, we provide the positions of Mars,
Phobos, and Deimos taken with the U.S. Naval Observatory 61-inch
astrometric reflector and 26-inch refractor from 1967 to 1997. 425
astrophotographic plates were measured with the digitizer of the Royal
Observatory of Belgium and reduced through an optimal process which
includes image, instrumental, and spherical corrections using the
UCAC4 catalog to provide the most accurate equatorial (RA, DEC)
positions.
Description:
Astrometric and measured data of Mars, Phobos and Deimos taken with
the U.S. Naval Observatory 61-inch astrometric reflector and 26-inch
refractor from 1967 to 1997.
Astrometric (RA,DEC) positions are geocentric observed positions
reduced from stars and refer to the ICRF. They were corrected for all
instrumental and spherical effects, except for the light time
propagation. Measured (x,y) positions are raw data of the stars and
satellites. They were obtained from initial extraction from the
plates, thus no instrumental or spherical effects were corrected.
(x,y) positions refer to the measured center of the planet. One should
select/reject available references carefully to ensure the most
accurate plate constants for the reduction process.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 42 777 Astrometric data of Mars (1967-1997)
table2.dat 42 640 Astrometric data of Phobos (1967-1997)
table3.dat 42 704 Astrometric data of Deimos (1967-1997)
table4.dat 68 5868 (x,y) raw data of stars and Phobos (1967-1997)
table5.dat 68 6914 (x,y) raw data of stars and Deimos (1967-1997)
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See also:
J/A+A/545/A144 : Astrometric observations of Deimos (Pasewaldt+, 2012)
J/A+A/487/755 : CCD observations of Martian Satellites (Veiga+, 2008)
J/A+A/488/361 : Mars Express astrometric obs. of Phobos (Willner+, 2008)
Byte-by-byte Description of file: table1.dat table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d JD Julian day of observation (TDB)
19- 28 F10.6 deg RAdeg Right ascension (ICRF)
33- 42 F10.6 deg DEdeg Declination (ICRF)
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Byte-by-byte Description of file: table4.dat table5.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d JD Julian Day of observation (TDB)
18- 20 A3 --- ID Object identifier (SNN) (1)
24- 32 F9.5 mm xmm Measured x position (millimeters)
36- 44 F9.5 mm ymm Measured y position (millimeters)
50- 56 F7.5 mm e_xmm Mean error of x position (millimeters)
62- 68 F7.5 mm e_ymm Mean error of y position (millimeters)
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Note (1): The object identifier is made as "SNN", where S denote stars and NN
the two-digit number in the plate. Two exceptions for the Martian
satellites for which the SNN identifier is replaced by corresponding NAIF
ID codes : "401" for Phobos, and "402" for Deimos.
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Acknowledgements:
The research leading to these results has received fundings from the
European Community's Seventh Framework Programme (FP7/2007-2013) under
grant agreement 263466 for the FP7-ESPaCE program.
Vincent Robert, robert(at)imcce.fr
(End) Vincent Robert [IPSA & IMCCE], Patricia Vannier [CDS] 19-Aug-2015