Search Results - "Jacobs, Christopher S."

Position and Proper Motion of Sagittarius A in the ICRF3 Frame from VLBI Absolute Astrometry by Gordon, David, de Witt, Aletha, Jacobs, Christopher S.

“…Sagittarius A* (Sgr A*) is a strong, compact radio source believed to be powered by a supermassive black hole at the galactic center. Extinction by dust and…”
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The Celestial Reference Frame at K Band: Imaging. I. The First 28 Epochs by de Witt, Aletha, Jacobs, Christopher S., Gordon, David, Bietenholz, Michael, Nickola, Marisa, Bertarini, Alessandra

“…We present K -band (24 GHz) images of 731 compact extragalactic radio sources with submilliarcsecond resolution, based on radio interferometric observations…”
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Overview and Status of the International Celestial Reference Frame as Realized by VLBI by de Witt, Aletha, Charlot, Patrick, Gordon, David, Jacobs, Christopher S.

“…Accurate measurement of angular positions on the sky requires a well-defined system of reference that is realized with accessible objects. The purpose of this…”
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Radio astrometry of the Cassini spacecraft with the very long baseline array by Jones, Dayton L., Folkner, William M., Jacobson, Robert A., Jacobs, Christopher S., Romney, Jonathan D., Dhawan, Vivek, Fomalont, Ed

“…The planetary ephemeris is a fundamental tool of astronomy that is essential for dynamical studies of the solar system, pulsar timing, tests of general…”
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The First Two Years of juno Spacecraft Astrometry with the Very Long Baseline Array by Jones, Dayton L., Romney, Jonathan D., Folkner, William M., Park, Ryan S., Jacobs, Christopher S., Dhawan, Vivek

“…The Very Long Baseline Array (VLBA) is a ten-antenna radio interferometer with baseline lengths up to 8000 km. It can provide astrometric measurements of…”
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Astrometry and geodesy with radio interferometry: experiments, models, results by Sovers, Ojars J., Fanselow, John L., Jacobs, Christopher S.

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Initial astrometry of the juno spacecraft orbiting jupiter by Jones, Dayton L., Romney, Jonathan D., Folkner, William M., Park, Ryan S., Jacobs, Christopher S., Dhawan, Vivek

“…We have been using the Very Long Baseline Array (VLBA) to measure accurate sky positions of the Juno spacecraft since its insertion into orbit around Jupiter…”
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The K-band (24 GHz) Celestial Reference Frame determined from Very Long Baseline Interferometry sessions conducted over the past 20 years by Krasna, Hana, Gordon, David, de Witt, Aletha, Jacobs, Christopher S

“…The third realization of the International Celestial Reference Frame (ICRF3) was adopted in August 2018 and includes positions of extragalactic objects at…”
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Position and Proper Motion of Sagittarius A in the ICRF3 Frame from VLBI Absolute Astrometry by Gordon, David, de Witt, Aletha, Jacobs, Christopher S

“…Sagittarius A* (Sgr A*) is a strong, compact radio source believed to be powered by a super-massive black hole at the galactic center. Extinction by dust and…”
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Atmospheric Media Calibration for the Deep Space Network by Bar-Sever, Yoaz E., Jacobs, Christopher S., Keihm, Stephen, Lanyi, Gabor E., Naudet, Charles J., Rosenberger, Hans W., Runge, Thomas F., Tanner, Alan B., Vigue-Rodi, Yvonne

“…Two tropospheric calibration systems have been developed at the Jet Propulsion Laboratory (JPL) using different technologies to achieve different levels of…”
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Atmospheric Media Calibration for the Deep Space Network : Automatic calibration systems have been developed for tracking spacecraft on inter-planetary missions; the systems account for communication delays due to atmospheric effects: Technical advances in deep space communications & tracking: Part 2 by BAR-SEVER, Yoaz E, JACOBS, Christopher S, KEIHM, Stephen, LANYI, Gabor E, NAUDET, Charles J, ROSENBERGER, Hans W, RUNGE, Thomas F, TANNER, Alan B, VIGUE-RODI, Yvonne

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On More than Two Decades of Celestial Reference Frame VLBI Observations in the Deep South: IVS-CRDS (1995-2021) by Weston, S, de Witt, A, Krasna, Hana, Bail, Karine Le, Hardon, Sara, Gordon, David, Fengchun, Shu, Fey, Alan, Schartner, Matthias, Basu, Sayan, Titov, Oleg, Behrend, Dirk, Jacobs, Christopher S, Hankey, Warren, Salguero, Febreico, Reynolds, John E

“…The International VLBI Service for Geodesy & Astrometry (IVS) regularly provides high-quality data to produce Earth Orientation Parameters (EOP), and for the…”
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Astrometry of Cassini with the VLBA to Improve the Saturn Ephemeris by Jones, Dayton L, Folkner, William M, Jacobson, Robert A, Jacobs, Christopher S, Dhawan, Vivek, Romney, Jon, Fomalont, Ed

“…Planetary ephemerides have been developed and improved over centuries. They are a fundamental tool for understanding solar system dynamics, and essential for…”
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Astrometry and geodesy with radio interferometry: experiments, models, results by Sovers, Ojars J, Fanselow, John L, Jacobs, Christopher S

“…Rev.Mod.Phys.70:1393-1454,1998 Summarizes current status of radio interferometry at radio frequencies between Earth-based receivers, for astrometric and…”
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Markarian 421's Unusual Satellite Galaxy by Gorham, Peter W, van Zee, Liese, Unwin, Stephen C, Jacobs, Christopher S

“…Astronomical Journal v. 119, no 4, page 1677 We present Hubble Space Telescope (HST) imagery and photometry of the active galaxy Markarian 421 and its…”
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