very long baseline interferometry

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very long baseline interferometry

astronomy

Also known as: VLBI

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July 14, 2026

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Very Long Baseline Interferometry (VLBI) is a technique in astronomy that links radio telescopes across vast distances to create a virtual telescope with extremely high resolution. Unlike conventional interferometers that use physical links, VLBI records signals at each antenna on magnetic disks, which are then processed together at a central location. This allows for baselines of thousands of kilometers, enabling astronomers to observe celestial objects with unprecedented detail. The successful operation of VLBI relies on precise timing synchronization, often using hydrogen masers as frequency standards. This method is crucial for studying distant astronomical phenomena and achieving resolutions comparable to optical telescopes.123

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radio telescope
Very long baseline interferometry
In conventional interferometers and arrays, coaxial cable, waveguide, or even fibre-optic links are used to distribute a common local-oscillator reference signal to each antenna and also to return the received signal from an individual antenna to a central laboratory where it…
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In conventional interferometers and arrays, coaxial cable, waveguide, or even fibre-optic links are used to distribute a common local-oscillator reference signal to each antenna and also to return the received signal from an individual antenna to a central laboratory where it…
Read More

astronomy
Telescopic observations
In another technique, called very long baseline interferometry (VLBI), simultaneous observations are made with radio telescopes thousands of kilometres apart; this technique requires very precise timing.
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In another technique, called very long baseline interferometry (VLBI), simultaneous observations are made with radio telescopes thousands of kilometres apart; this technique requires very precise timing.
Read More

radio jet
” In very long baseline interferometry (VLBI) experiments performed by combining the simultaneous observations of several telescopes spaced by thousands of kilometres, radio astronomers have discovered that some of the compact radio sources located in the nuclei of active galaxies break into several components at high angular…
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” In very long baseline interferometry (VLBI) experiments performed by combining the simultaneous observations of several telescopes spaced by thousands of kilometres, radio astronomers have discovered that some of the compact radio sources located in the nuclei of active galaxies break into several components at high angular…
Read More

radio telescope
Very long baseline interferometry
…by using the technique of very long baseline interferometry (VLBI). In early VLBI systems the signals received at each element were recorded by broad-bandwidth videotape recorders located at each antenna. More recently, with the advent of inexpensive, reliable computer disk drives, the data are recorded on disks. The disks are…
Read More
…by using the technique of very long baseline interferometry (VLBI). In early VLBI systems the signals received at each element were recorded by broad-bandwidth videotape recorders located at each antenna. More recently, with the advent of inexpensive, reliable computer disk drives, the data are recorded on disks. The disks are…
Read More