No antenna tracking is required, since it is the entire sky, rather than individual stars, which we seek to scan. While target searching antennas must be constantly moved, sky survey radiotelescopes are operated in what's called meridian transit mode, in which it is the Earth's rotation which turns them. Their Project Phoenix employs some of the world's best radiotelescopes. But since large antennas have quite narrow beamwidth, they see only a small portion of the sky at a given time. The sky survey component would be better performed with antennas of moderate size.
Smaller antennas can see more sky within their beam patterns, but have less gain.
We achieve reasonable sensitivities through digital signal processing, but the antennas need to scan for extremely long periods of time. The sky survey approach seems ideally suited to the community of radio amateurs and microwave experimenters. This is the area in which The SETI League is concentrating its efforts, through our own Project Argus . The SETI League, Inc.