The Allen Telescope Array (ATA) is a centimeter-wavelength radio telescope with the potential to produce unique science that cannot be done with any other instrument. The ATA is the first radio telescope designed for commensal observing; it will simultaneously produce sensitive SETI (Search for Extraterrestrial Intelligence) surveys as well as large area continuum and spectroscopic surveys for conventional radio astronomy. The science of the ATA is enabled by a number of innovative technical developments. The ATA may serve as a prototype for the US design of the Square Kilometer Array (SKA), a next generation radio telescope currently in the planning phase. Located in Hat Creek, CA, formerly the site of the BIMA millimeter-wavelength array, the ATA will begin with 42 offset Gregorian antennas with continuous frequency response from 0.5 to 11.2 GHz, with an ultimate goal of 350 antennas.
