very-long-baseline interferometry
(VLBI)
(interferometry based upon storing timing data at each telescope)
The term very-long-baseline interferometry (VLBI) is
self-explanatory, but the term is generally used for
radio interferometry with
baselines sufficiently long to make real-time processing of the signals
unwieldy, which is generally true of interferometry
using receivers at separate sites. Among the longest such
baselines have been between sites on opposite sides of the Earth
(Earth-sized VLBI),
and space telescopes (e.g., Spektr-R) have been included
for even longer baselines.
The signal data as well as its timing are stored at each
telescope and later processing of the collected data determines
the exact direction from which the signal came, allowing telescopes
far apart (e.g., thousands of miles) to be used. Its use has
achieved angular resolutions in the 10 microarcsecond range.
VLBI arrays often use existing distantly-separated telescopes,
and may be short-term projects, such as for specific
surveys. Some VLBI arrays:
A more recent development is electronic very-long-baseline interferometry (e-VLBI), which is near-real-time transmission
of the data for immediate analysis. (The challenge is that the amount
of observation data necessary to carry out the analysis can be so
large as to make this difficult or impossible.)
The purpose of VLBI is to observe radio sources in detail, but a byproduct
is the measurement of the distance between receivers down to the
millimeter range, precise enough to reveal the effects of
plate tectonics.
(measurement,EMR,interferometry,radio)
Further reading:
https://en.wikipedia.org/wiki/Very-long-baseline_interferometry
https://ui.adsabs.harvard.edu/abs/2003ASPC..300....1C/abstract
https://www.europhysicsnews.org/articles/epn/pdf/1988/04/epn19881904p46.pdf
https://www.haystack.mit.edu/wp-content/uploads/2020/07/conf_TOW2019_lecture_Elosegui.pdf
https://science.nrao.edu/science/meetings/2018/16th-synthesis-imaging-workshop/talks/Deller_VLBI.pdf
https://www.astron.nl/eris2017/Documents/ERIS2017_L12_Campbell_no-anim.pdf
https://fermi.gsfc.nasa.gov/science/mtgs/vlbi/Paragi-Poster.pdf
Referenced by pages:
ARISE
Australia Telescope Compact Array (ATCA)
correlator
Dominion Radio Astrophysical Observatory (DRAO)
DSA-2000
Earth rotation synthesis
Earth-sized VLBI
electronic very-long-baseline interferometry (e-VLBI)
European VLBI Network (EVN)
Gould's Belt Distances Survey (GOBELINS)
Green Bank 140 Foot Telescope
Green Bank Observatory (GBO)
Greenland Telescope (GLT)
HALCA
high-resolution imaging
ICRF
International Celestial Reference System (ICRS)
jet
Jodrell Bank Observatory (JBO)
Long Baseline Array (LBA)
Mark II (MKII)
maser
Max Planck Institute for Radio Astronomy (MPIR)
Next Generation Very Large Array (ngVLA)
OH/IR source
parallax
radio astronomy
Sardinia Radio Telescope (SRT)
SELENE
speckle masking
spectral correlator
Spektr-R
Swedish-ESO Submillimetre Telescope (SEST)
transit telescope
VERA
Very Long Baseline Array (VLBA)
Index