The SETI instrument development plan

The architecture of the instrument system for the SETI (Search for Extraterrestrial Intelligence) program is briefly described and the development approach used to implement the operational instruments is discussed. The two versions of the instrument system include a target survey instrument to observe at a very high sensitivity a selected set of interesting stars that have particular a priori promise, and a sky survey instrument to observe the entire celestial sphere at a lower sensitivity. The targeted survey utilizes the 305 meter antenna at Arecibo, Puerto Rico, a 64 meter DSN antenna, and other large radio telescopes. The Arecibo instrument provides the highest sensitivity by virtue of the antenna gain. The antenna line feeds cover an instantaneous frequency range of 50 MHz (tunable over 100 MHz), while the multichannel spectrum analyzer/signal detector is capable of analyzing a frequency segment 16 MHz wide with a maximum resolution of 1 Hz. The sky survey employs a listen-only, 34 meter antenna. The SETI breadboard development is also described.