Space VLBI Technique

Space VLBI is a technique of Very Long Baseline Interferometry (VLBI) that is used to extend the baseline length and improve the angular resolution compared to ground-based VLBI. The resolution of the technique is sub-milliarcsecond at wavelengths of a few cm, and can be better than 100 microarcseconds at wavelengths of 1 cm and shorter. Radio interferometry is carried out by using a space-based radio telescope as one element of an array together with a set of ground-based radio telescopes. For an imaging interferometer, the space radio telescope generally is in a highly elliptical orbit and moves fairly rapidly, enabling synthesis of a large imaging aperture in a typical observing time of about 12 hours. Typically, the observations require one or more science telemetry stations that supply a highly accurate clock to the spacecraft as well as recording the wideband VLBI data for later processing at a special-purpose VLBI correlator.

• Abstract of ASP article
• Full Article (19 MB, preprint of ASP Conf. Series 180, page 513, 1999)
• Presentation to Synthesis Imaging Summer School in 2000

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