Russian VLBI network “Quasar”: Current status and outlook

This paper presents the past, present and future status of the Russian VLBI network “Quasar”. This network has been developed for at least 20 years by the Institute of Applied Astronomy of the Russian Academy of Sciences (IAA RAS). The equipment installed currently at each “Quasar” station and the facilities for processing observational data are described briefly. The latest results are presented, including the Earth orientation parameters (EOP) determined from the “Quasar” VLBI data and comparison with those from other processing centers. Our future plans to extend the “Quasar” VLBI network to the east and to the west will be carried out by establishing the Ussurijsk station in the Far East and the Russian-Cuban station in the west. They are considered in the context of the Russian section activity in the GGOS project. The expected improvement of the EOP determination accuracy can be obtained within the future configuration of the “Quasar” network, which is proved by simulation. Keywords: Russian VLBI network “Quasar”, VLBI co-location station, Space geodesy technique, Global Geodetic Observing System (GGOS

VizieR Online Data Catalog: VLBI ICRF2 (Fey+, 2015)

2016yCat..51500058F - VizieR On-line Data Catalog: J/AJ/150/58. Originally published in: 2015AJ....150...58FWe present the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry observations. The earliest observations used are from 1979 August and the latest are from 2009 March. ICRF2 consists of accurate positions of 295 new "defining" sources and positions of 3119 additional compact radio sources to densify the frame. ICRF2 has more than 5 times as many sources as ICRF1 (Ma et al. 1997, cat. I/251), is roughly 5-6 times more accurate, and is nearly twice as stable in the orientation of its axes.(3 data files)

International Celestial Reference Frame 2, ICRF2 (Ma+, 2009)

2013yCat.1323....0M-VizieR On-line Data Catalog: I/323. Originally published in: IERS Technical Note 35 (2009)This Technical Note describes the generation by an international team of the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry (VLBI) observations. ICRF2 contains precise positions of 3414 compact radio astronomical sources, more than five times the number as in the first ICRF, hereafter ICRF1. Further, the ICRF2 is found to have a noise floor of only 40μas, some 5-6 times better than ICRF1, and an axis stability of 10μas, nearly twice as stable as ICRF1. Alignment of ICRF2 with the International Celestial Reference System (ICRS) was made using 138 stable sources common to both ICRF2 and ICRF1-Ext2. Future maintenance of ICRF2 will be made using a set of 295 new "defining" sources selected on the basis of positional stability and the lack of extensive intrinsic source structure. The stability of these 295 defining sources, and their more uniform sky distribution eliminates the two largest weaknesses of ICRF1. (2 data files)

THE SECOND REALIZATION OF THE INTERNATIONAL CELESTIAL REFERENCE FRAME BY VERY LONG BASELINE INTERFEROMETRY

We present the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry observations. ICRF2 contains precise positions of 3414 compact radio astronomical objects and has a positional noise floor of ∼40 μas and a directional stability of the frame axes of ∼10 μas. A set of 295 new “defining” sources was selected on the basis of positional stability and the lack of extensive intrinsic source structure. The positional stability of these 295 defining sources and their more uniform sky distribution eliminates the two greatest weaknesses of the first realization of the International Celestial Reference Frame (ICRF1). Alignment of ICRF2 with the International Celestial Reference System was made using 138 positionally stable sources common to both ICRF2 and ICRF1. The resulting ICRF2 was adopted by the International Astronomical Union as the new fundamental celestial reference frame, replacing ICRF1 as of 2010 January 1