The Berkeley Seti Program: Serendip IV Instrumentation

Abstract

AbstractThe SERENDIP program is an ongoing search for narrow band radio signals from extraterrestrial civilizations. Each generation SERENDIP instrument has on average been about 35 times more powerful than its predecessor. In this paper we discuss the hardware design of the latest generation instrument, SERENDIP IV, which will be deployed in early 1997 for a 21 cm sky survey at the National Astronomy and Ionospheric Center’s 305 meter radio telescope in Arecibo, Puerto Rico. SERENDIP IV is a 167 million channel spectrum analyzer, covering a 100 Mhz bandwidth, with 0.6 Hz resolution and a 1.7 second integration time. SERENDIP IV’s modular design incorporates a bank of digital mixers and filters to separate the 100 MHz band into forty 2.5 MHz sub-bands. Each 2.5 MHz sub-band is further broken down into 0.6 Hz bins by means of a four million point fast Fourier transform. The resulting power spectra are analyzed by 40 high speed processors. Narrow band signals having power significantly above background noise levels are recorded along with telescope coordinates, time, and frequency. The data are sent in real time to Berkeley for analysis. SERENDIP IV hardware is also utilized by the Ohio State University SETI program and pulsar programs at Nancay Observatory (France), the US Naval Research Lab, the Effelsberg telescope (Germany), NRAO’s Greenbank Observatory and NAIC’s Arecibo Observatory.