Drift scan is a relatively low-cost technique for surveying a portion of the sky using a CCD, e.g., with amateur equipment. It can be effective in identifying movement of observed objects such satellites or minor planets.
The technique has the advantage that the telescope remains stationary. It is a method of scanning the sky as it passes through the field of view, the particular technique being that extraction of data from the CCD is synchronized with the rate at which a pixel of the CCD moves to new positions on the celestial sphere. The telescope and CCD must be oriented so as to allow such a set-up. The technique is only effective with portions of the sky near the celestial equator. The product of such a drift scan is an image consisting of an east-west strip across the sky.