1998 Report to IACG by Panel 3 on Space VLBI
October 7, 1998
Berne, Switzerland
Joel Smith
Panel Charter
To serve as an advocacy and planning forum for the development of the appropriate technologies and infrastructure for possible future space VLBI missions.
Specific planned tasks include (taken from Frank Jordan’s December 1997 IACG presentation):
1. Transfer flight operations lessons learned from VSOP experience to future projects, in areas such as: data acquisition/recording, correlation/image formation, calibrations/testing, navigation/positioning.
2. Fold science results from VSOP into logical technical influence on future mission designs, in areas such as: frequencies of observations, orbit parameters, antenna size, sensitivity.
3. Recommend designation of standards for both space and ground VLBI systems, in areas such as: data recorders, data correlators, formats and interfaces, channel definitions.
4. Recommend data link (GHz bandwidth) frequency allocations.
5, Recommend target goals for supporting technology developments, in areas such as antenna surface accuracy.
Panel Members
(official members with ***)
EUROPE Gurvits, L. (JIVE)
Olthof, H. (ESTEC)***
Schilizzi, R. (JIVE)
JAPAN Hirabayashi, H. (ISAS)***
Inoue, M. (ISAS/NAO)
Kawaguchi, N. (ISAS/NAO)***
RUSSIA Andreyanov, V. (ASC)***
Kardashev, N. (ASC)***
Slysh, V. (ASC)***
U.S. Preston, R. (JPL)
Smith, J. (JPL)***
Ulvestad , J. (NRAO)***
Meetings & Attendance
Neuchatel, Switzerland, February 25
Members present:
ESA: Gurvits, Olthof, and Schilizzi
ISAS: Hirabayashi and Inoue
NASA: Preston, Smith, and Ulvestad
RSA: Andreyanov, Kardashev, and Slysh
Also attending:
CSIRO/Australia: Jauncey and Wellington
CSA/Canada: Cannon and Dewdney
USA: Altunin, Burke, and Romney
Nagoya, Japan, July 18
Members attending:
ESA: Gurvits, Schilizzi
ISAS: Hirabayashi, Inoue, Kawaguchi
NASA: Preston, Smith, Ulvestad
Also attending:
CSIRO/Australia: Jauncey
CSA/Canada: Cannon, Dougherty
MPIFR/Germany: Porcas
ISAS: Edwards, Hirosawa, Horiuchi, Kobayashi, Moellenbrock, Murata
U.S.: Altunin, Burke, Langston, Murphy, Romney, Tingay
Space VLBI Mission Set
VSOP Currently in flight Japan (1/8 Gbps)
RadioAstron Under development Russia (1/8 Gbps)
VSOP-2 Preliminary Study Japan (1 Gbps)
Millemetron Preliminary Study Russia (1 Gbps)
ARISE Preliminary Study U.S. (8 Gbps)
1998 Panel Accomplishments – Link Frequency Allocations
Space VLBI missions do not have on-board recorders for wide-band science
Wide-band science digitized on-board to preserve timing
High rate (1 to 8 Gbps) digital data down-linked to tracking stations
Frequency allocations below 32 GHz do not support these high rates
Promoted allocations at 37 GHz (1 GHz wide) and 71 GHz (3 GHz wide)
Space Frequency Coordination Group (SFCG) met in Japan in July
SFCG considering allocation for VSOP-2 at 37 GHz
1998 Panel Accomplishments – Data Rate Developments
Current wide-band instrumentation recorders operate routinely at 128 Mbps
Canada S-2 128 Mbps to 256 Mbps
Europe Mark-4 128 Mbps to 512 Mbps
Japan K-4 128 Mbps to 256 Mbps
U.S. VLBA 128 Mbps to 256 Mbps
Panel is promoting next generation instrumentation recorders
Canada S-3 & S-4 512 Mbps to 4 Gbps
Japan GBR 1 Gbps
Japan Sony 512 Mbps to 4 Gbps
U.S. VLBA extensions 512 Mbps to 1 Gbps
Canadians in Toronto report testing in 1998 of three "digital video" tape transports from broadcast industry, and selection of a candidate transport for prototyping.
Current correlators operate routinely at 128 Mbp
sExtensions to higher rates are underway
Canada Penticton 512 Mbps with 6 stations
Europe Dwingeloo 512 Mbps with 16 stations
to 2 Gbps with 4 stations
Japan Mitaka 512 Mbps with 10 stations
to 1 Gbps with 5 stations
U.S. VLBA 512 Mbps with 10 stations
to 1 Gbps with 5 stations
Plans for 1999
Continued dialogue on higher rate instrumentation recorders
Continued dialogue on 37 GHz and 71 GHz frequency allocations
Standard channelization schemes from 1 Gbps to 8 Gbps
Application of CCSDS (data standards) to high rate data streams