An Etymological Dictionary of Astronomy and Astrophysics

A geometric plane defined for the analysis/processing of → interferometer observations, for which the axes are conventionally termed u and v.

The plane is at right angles to a direction from which radiation is being received from the sky.

Unlike a typical telescope, a → radio interferometer cannot produce an image of the sky directly. Instead it measures the → Fourier transform of the sky brightness distribution in the uv plane. The Fourier transform relates the → interference pattern to the intensity on the sky. A measurement on a particular → baseline corresponds to a point on this plane with coordinates u and v, at a distance from the origin equal to the projected length of the baseline measured in wavelengths. Two telescopes form one baseline which represents one point in uv plane;

three telescopes create three baselines and are therefore represented by three points in uv plane.

Good uv coverage requires many simultaneous baselines amongst many antennas, or many sequential observations from a few antennas.

Good coverage of points is essential for high-quality

→ aperture synthesis mapping.

See also: u and v conventional symbols; → plane.