Observations of 384 Radio Sources at a Frequency of 158 Mc/s with a Long Baseline Interferometer

The angular sizes of 384 radio sources have been investigated by means of interferometric measurements at 158 Mc/s. For each source, observations were made at transit with one or more of four values of aerial separation, in the range 2 200 to 61 100 wavelengths. All the baselines had directions close to east-west. The problems of calibrating observations at long baselines are discussed. It is estimated that the combined r.m.s. errors in fringe visibility do not exceed 50 per cent.