Phase-referencing allows phase calibration of VLBI data. Using regular observations of a nearby calibrator source, delay, delay-rate, and phase corrections can be derived and their eeects removed from the target source visibility data. This technique allows imaging much weaker objects than is possible via fringe-tting methods. We examine the main types of phase error in VLBI observations (geome...

The special problems encountered when performing spectral-line VLBI observations are discussed in this Chapter. In particular, the usefulness of Fourier transforming measured visibility data with respect to time, delay or frequency for purposes of fringe detection and calibration is clariied.

Throughout the summer development has continued on the next generation of the Small Radio Telescope for use as a Very Long Baseline Interferometry type interferometer. This paper discusses the difficulties with setting up this new interferometer and presents some results obtained using this small radio telescope interferometer. We used 3 small radio telescopes to form one baseline of about 5 me...