Dirk Behrend & Chopo Ma, 26-April-2017
Dirk Behrend & Chopo Ma
IVS Report 2016/17
GGOS Bureau of N&O, Vienna, Austria
April 26, 2017
Dirk Behrend & Chopo Ma, 26-April-2017
Directing Board
Lead:
• Chair: Axel Nothnagel, Univ Bonn [1st term ends in May ‘17]
• Director CC: Dirk Behrend, NVI, Inc./NASA GSFC
Directing Board Election results (6 of 16 seats):
• Elected Representatives: Francisco Colomer (Networks), Axel Nothnagel (Analysis), and Thomas Hobiger (Technology Development)
• Elected At-Large Members: Evgeny Nosov (IAA, Russia), Takahiro Wakasugi (GSI, Japan), and Guangli Wang (SHAO, China)
Directing Board meetings:
• Last meeting: Westford, MA, USA on 15 October ‘16
• Next meeting: Gothenburg, Sweden on 19 May ‘17
Dirk Behrend & Chopo Ma, 26-April-2017
VLBI Observations of Near-Field Targets
• Workshop in Bonn, Germany on October 5–6, 2016
• About 50 participants, 25 presentations; WG7 splinter meeting
• Talks: http://www3.mpifr-bonn.mpg.de/div/meetings/vonft/talks.html
• Topics: Near-field delay model, APOD (CubSat w/ VLBI transmitter),
Chang’E-3 lander (VLBI transmitter on moon), GNSS observations…
Dirk Behrend & Chopo Ma, 26-April-2017
5th Int’l VLBI Technology Workshop
• Workshop at MIT Haystack Observatory, October 12–14, 2016
• Geodetic/Astrometric (IVS) and Astronomy communities, annual WS
• About 70 participants from around the world
• Topics: – Simplification of signal-chain; direct-RF-sampling
– New-generation of high-performance frequency standards
– Towards commodity computing for tasks now done with FPGAs
– Tbps-scale data recording/transmission
– Tbps-scale correlation and scaling to many stations
– VLBI from space (including space-to-space baselines)
– TeraHz VLBI - what are the limits?
• Presentations: http://www.haystack.mit.edu/workshop/ivtw2016/
presentations_2016.htm
Dirk Behrend & Chopo Ma, 26-April-2017
9th Technical Operations Workshop
• Workshop at MIT Haystack Observatory, April 30 – May 4, 2017
• Hands-on training of technical station staff
• 62 registered participants from 17 countries
• TOW organized every two years
• Challenge of having both legacy and VGOS broadband systems covered
• http://www.haystack.mit.edu/workshop/TOW2017/Index.htm
Dirk Behrend & Chopo Ma, 26-April-2017
Dismantling of Tsukuba
• Tsukuba 32-m antenna dismantled in February/March 2017
• Functionality replaced by Ishioka 13.2-m antenna
Dirk Behrend & Chopo Ma, 26-April-2017
VGOS Roll-out Progress (1/2)
Station Recent milestone VGOS broadband
GGAO Regular VGOS tests ready
Westford Regular VGOS tests ready
Wettzell South Regular VGOS tests ready
Yebes Regular VGOS tests ready
Ishioka Regular S/X observing ready (but is S/X now)
Kokee Park Regular VGOS tests ready
AuScope (Hobart) Upgrade hardware ordered mid-2017
AuScope (Yg, Ke) Upgrade hardware ordered end-2017
Onsala Inauguration in May 2017 mid-2017
Santa Maria Tri-band receiver installed late 2017
Badary Fixed broadband system 2017 (S/X/Ka)
Zelenchukskaya Fixed broadband system 2017 (S/X/Ka)
Dirk Behrend & Chopo Ma, 26-April-2017
VGOS Roll-out Progress (2/2)
Station Recent milestone VGOS broadband
Sheshan Foundation work completed 2018
Tenerife RT assembled at factory 2018
Ny Ålesund Antennas erected at site 2018
HartRAO Concrete tower completed 2018
McDonald Tender released 2019
Metsähovi Site preparation work started 2019
Svetloe Funding secured 2019
Flores Site selected 2020
Tahiti Site selected 2020
Dirk Behrend & Chopo Ma, 26-April-2017
Courtesy R. Haas
25 m
20 m OTT1 OTT2
Onsala Twin Telescope (OTT)
Dirk Behrend & Chopo Ma, 26-April-2017
Hartebeesthoek, South Africa
Concrete tower completed in February 2017
Groundbreaking in March 2016
Dirk Behrend & Chopo Ma, 26-April-2017
• Test sessions observed every 2 weeks
24-hour observing
with 3 to 5 stations (3 North America, 2 Europe)
correlation at Haystack Observatory
equipment differences for the various stations
• Testing and improving of station operations and correlation
• Not full end-to-end (until geodetic results) tests
VGOS Tests
Dirk Behrend & Chopo Ma, 26-April-2017
Diversity of VGOS Equipment
• Backends – RDBE (Roach-based Digital Back End): joint effort between MIT Haystack
Observatory and NRAO; two personalities (Polyphase Filter Bank, PFB; Direct
Digital Converter, DDC); various flavors:
• RDBE, RDBE-G, R2DBE
– DBBC (Digital Base Band Converter): European effort by G. Tuccari; various
flavors:
• DBBC, DBBC2, DBBC3
– ADS300+: Japanese development, DDC-based
– CDAS (Chinese Data Acquisition System): developed at SHAO (X. Zhang), PFB
and DDC versions
– BRAS (Russian Broadband Acquisition System): developed at IAA (E. Nosov)
• Feeds – Eleven: developed at Chalmers University, available through Omnisys
Instruments
– QRFH (Quadruple Ridged Flared Horn): developed at Caltech
Dirk Behrend & Chopo Ma, 26-April-2017
Continuous VLBI Campaign CONT17
Legacy S/X network of geodetic IVS stations
Legacy S/X network of 10 VLBA stations plus select geodetic IVS stations
Dirk Behrend & Chopo Ma, 26-April-2017
CONT17: VGOS Demonstration Network
Observing period: subset of 15-day period (from Nov 28 to Dec 12, 2017)
VGOS broadband network of up to 8 VGOS stations