A technique for surveying the sky in which the telescope is fixed and the rotation of the Earth carries celestial objects through its beam. Many radio interferometers designed for survey work are not physically steerable and rely on drift scanning to cover large areas of sky. Drift scanning has the advantage of a uniform, precise scan rate, and consequent accurate positioning, but it is relatively inflexible. See also Raster Scan.
Subjects: Astronomy and Astrophysics.