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Gordon D, Jacobs C, Beasley A, Peck A, Gaume R, Charlot P, Fey A, Ma C, Titov O, Boboltz D. Second Epoch VLBA Calibrator Survey Observations - VCS-II. THE ASTRONOMICAL JOURNAL 2016; 151:154. [PMID: 29937549 PMCID: PMC6010998 DOI: 10.3847/0004-6256/151/6/154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Six very successful VLBA calibrator survey campaigns were run between 1994 and 2007 to build up a large list of compact radio sources with positions precise enough for use as VLBI phase reference calibrators. We report on the results of a second epoch VLBA Calibrator Survey campaign (VCS-II) in which 2400 VCS sources were re-observed at X and S bands in order to improve the upcoming third realization of the International Celestial Reference Frame (ICRF3) as well as to improve their usefulness as VLBI phase reference calibrators. In this survey, some 2062 previously detected sources and 324 previously undetected sources were detected and revised positions are presented. Average position uncertainties for the re-observed sources were reduced from 1.14 and 1.98 mas to 0.24 and 0.41 mas in RA and Declination, respectively, or by nearly a factor of 5. Minimum detected flux values were approximately 15 and 28 mJy in X and S bands, respectively, and median total fluxes are approximately 230 and 280 mJy. The vast majority of these sources are flat-spectrum sources, with ~82% having spectral indices greater than -0.5.
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Affiliation(s)
- David Gordon
- NVI Inc @ NASA Goddard Space Flight Center, Code 698.2, Greenbelt, MD 20771,
| | | | | | - Alison Peck
- National Radio Astronomy Observatory, Charlottesville, VA,
| | | | - Patrick Charlot
- Univ. Bordeaux, LAB, UMR 5804, F-33270 Floirac, France and CNRS, LAB, UMR 5804, F-33270 Floirac, France,
| | - Alan Fey
- US Naval Observatory, Washington, DC,
| | - Chopo Ma
- NASA Goddard Space Flight Center, Greenbelt, MD 20771,
| | - Oleg Titov
- Geosciences Australia, Symonston, ACT 2609, Australia,
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Schüler T, Kronschnabl G, Plötz C, Neidhardt A, Bertarini A, Bernhart S, la Porta L, Halsig S, Nothnagel A. Initial Results Obtained with the First TWIN VLBI Radio Telescope at the Geodetic Observatory Wettzell. SENSORS 2015; 15:18767-800. [PMID: 26263991 PMCID: PMC4570345 DOI: 10.3390/s150818767] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 07/16/2015] [Accepted: 07/17/2015] [Indexed: 11/16/2022]
Abstract
Geodetic Very Long Baseline Interferometry (VLBI) uses radio telescopes as sensor networks to determine Earth orientation parameters and baseline vectors between the telescopes. The TWIN Telescope Wettzell 1 (TTW1), the first of the new 13.2 m diameter telescope pair at the Geodetic Observatory Wettzell, Germany, is currently in its commissioning phase. The technology behind this radio telescope including the receiving system and the tri-band feed horn is depicted. Since VLBI telescopes must operate at least in pairs, the existing 20 m diameter Radio Telescope Wettzell (RTW) is used together with TTW1 for practical tests. In addition, selected long baseline setups are investigated. Correlation results portraying the data quality achieved during first initial experiments are discussed. Finally, the local 123 m baseline between the old RTW telescope and the new TTW1 is analyzed and compared with an existing high-precision local survey. Our initial results are very satisfactory for X-band group delays featuring a 3D distance agreement between VLBI data analysis and local ties of 1 to 2 mm in the majority of the experiments. However, S-band data, which suffer much from local radio interference due to WiFi and mobile communications, are about 10 times less precise than X-band data and require further analysis, but evidence is provided that S-band data are well-usable over long baselines where local radio interference patterns decorrelate.
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Affiliation(s)
- Torben Schüler
- Geodetic Observatory Wettzell, Federal Agency for Cartography and Geodesy, Sackenrieder Str. 25, 93444 Bad Koetzting, Germany.
- Faculty of Aerospace Engineering, University of the Federal Armed Forces Munich, 85777 Neubiberg, Germany.
| | - Gerhard Kronschnabl
- Geodetic Observatory Wettzell, Federal Agency for Cartography and Geodesy, Sackenrieder Str. 25, 93444 Bad Koetzting, Germany.
| | - Christian Plötz
- Geodetic Observatory Wettzell, Federal Agency for Cartography and Geodesy, Sackenrieder Str. 25, 93444 Bad Koetzting, Germany.
| | - Alexander Neidhardt
- Geodetic Observatory Wettzell, Technische Universität München, Sackenrieder Str. 25, 93444 Bad Koetzting, Germany.
| | - Alessandra Bertarini
- Institute of Geodesy and Geoinformation, University of Bonn, Nußallee 17, 53115 Bonn, Germany.
- Max Planck Institute for Radio Astronomy, Auf dem Hügel 69, 53121 Bonn, Germany.
| | - Simone Bernhart
- Institute of Geodesy and Geoinformation, University of Bonn, Nußallee 17, 53115 Bonn, Germany.
| | - Laura la Porta
- Institute of Geodesy and Geoinformation, University of Bonn, Nußallee 17, 53115 Bonn, Germany.
| | - Sebastian Halsig
- Institute of Geodesy and Geoinformation, University of Bonn, Nußallee 17, 53115 Bonn, Germany.
| | - Axel Nothnagel
- Institute of Geodesy and Geoinformation, University of Bonn, Nußallee 17, 53115 Bonn, Germany.
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Heki K, Foulger GR, Julian BR, Jahn CH. Plate dynamics near divergent boundaries: Geophysical implications of postrifting crustal deformation in NE Iceland. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/93jb00781] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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MacMillan DS, Gipson JM. Atmospheric pressure loading parameters from very long baseline interferometry observations. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/94jb01190] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lundgren P, Saucier F, Palmer R, Langon M. Alaska crustal deformation: Finite element modeling constrained by geologic and very long baseline interferometry data. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/95jb00237] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Herring TA. Submillimeter horizontal position determination using very long baseline interferometry. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/91jb02649] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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MacMillan DS, Ma C. Evaluation of very long baseline interferometry atmospheric modeling improvements. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/93jb02162] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Sauber J, Carver G, Cohen S, King R. Crustal deformation and the seismic cycle across the Kodiak Islands, Alaska. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jb003626] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jeanne Sauber
- Planetary Geodynamics Laboratory; NASA's Goddard Space Flight Center; Greenbelt Maryland USA
| | - Gary Carver
- Department of Geology; Humboldt State University; Arcata California USA
| | - Steven Cohen
- Planetary Geodynamics Laboratory; NASA's Goddard Space Flight Center; Greenbelt Maryland USA
| | - Robert King
- Department of Earth, Atmospheric, and Planetary Science; Massachusetts Institute of Technology; Cambridge Massachusetts USA
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Beavan J, Tregoning P, Bevis M, Kato T, Meertens C. Motion and rigidity of the Pacific Plate and implications for plate boundary deformation. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jb000282] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- J. Beavan
- Institute of Geological and Nuclear Sciences; Lower Hutt New Zealand
| | - P. Tregoning
- Research School of Earth Sciences; Australian National University; Canberra Australia
| | - M. Bevis
- School of Ocean and Earth Science and Technology; University of Hawaii; Honolulu Hawaii USA
| | - T. Kato
- Earthquake Research Institute; University of Tokyo; Tokyo Japan
| | - C. Meertens
- University NAVSTAR Consortium; Boulder Colorado USA
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Cohen SC, Freymueller JT. Crustal uplift in the south central Alaska subduction zone: New analysis and interpretation of tide gauge observations. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jb900419] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Piersanti A, Spada G, Sabadini R. Global postseismic rebound of a viscoelastic Earth: Theory for finite faults and application to the 1964 Alaska earthquake. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/96jb01909] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Niell AE. Global mapping functions for the atmosphere delay at radio wavelengths. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95jb03048] [Citation(s) in RCA: 946] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Molnar P, Gipson JM. A bound on the rheology of continental lithosphere using very long baseline interferometry: The velocity of south China with respect to Eurasia. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95jb02503] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Geodetic measurement of static displacement associated with the 1987–1988 Gulf of Alaska earthquakes. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd023p0233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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16
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Space geodesy and plate motions. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd023p0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Geodetic results from Lageos 1 and Doris satellite data. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd023p0081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Ryan JW, Clark TA, Ma C, Gordon D, Caprette DS, Himwich WE. Global scale tectonic plate motions measured with CDP VLBI data. CONTRIBUTIONS OF SPACE GEODESY TO GEODYNAMICS: CRUSTAL DYNAMICS 1993. [DOI: 10.1029/gd023p0037] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Ma C, Ryan JW, Gordon D, Caprette DS, Himwich WE. Reference frames from CDP VLBI data. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd024p0121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Plate tectonics from SLR and VLBI global data. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd023p0051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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21
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Horizontal crustal deformation and large scale plate motions inferred from space geodetic techniques. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd023p0021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Constraints on deformation of the resurgent dome, Long Valley Caldera, California from space geodesy. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd023p0193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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23
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Improvements in the accuracy of geodetic VLBI. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/gd025p0047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Abstract
Much of the success of plate tectonics can be attributed to the near rigidity of tectonic plates and the availability of data that describe the rates and directions of motion across narrow plate boundaries \m=~\1 to 60 kilometers wide. Nonetheless, many plate boundaries in both continental and oceanic lithosphere are not narrow but are hundreds to thousands of kilometers wide. Wide plate boundary zones cover \m=~\15 percent of Earth's surface area. Space geodesy, which includes very long baseline radio interferometry, satellite laser ranging, and the global positioning system, is providing the accurate long-distance measurements needed to estimate the present motion across and within wide plate boundary zones. Space geodetic data show that plate velocities averaged over years are remarkably similar to velocities averaged over millions of years.
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Estabrook CH, Nábělek JL, Lerner-Lam AL. Tectonic model of the Pacific-North American Plate Boundary in the Gulf of Alaska from broadband analysis of the 1979 St. Elias, Alaska, earthquake and its aftershocks. ACTA ACUST UNITED AC 1992. [DOI: 10.1029/92jb00131] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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