SERENDIP takes advantage of ongoing "mainstream" radio telescope observations as a "piggy-back" or "commensal" program. Rather than having its own observation program, SERENDIP analyzes deep space radio telescope data that it obtains while other astronomers are using the telescope.
Background
The initial SERENDIP instrument was a 100-channel analog radio spectrometer covering 100kHz of bandwidth. Subsequent instruments have been significantly more capable, with the number of channels doubling roughly every year. These instruments have been deployed at a large number of telescopes including the NRAO 90m telescope at the Green Bank Observatory and the Arecibo 305m telescope.
SERENDIP observations have been conducted at frequencies between 400 MHz and 5 GHz, with most observations near the so-called Cosmic Water Hole (1.42GHz (21cm) neutral hydrogen and 1.66GHz hydroxyl transitions).
Projects
SERENDIP V was installed at the Arecibo Observatory in June 2009. The digital back-end instrument was an FPGA-based 128 million-channel digital spectrometer covering 200MHz of bandwidth. It took data commensally with the seven-beam Arecibo L-band Feed Array (ALFA).[2]
The program has found around 400 suspicious signals, but there is not enough data to prove that they belong to extraterrestrial intelligence.[5] In September–October 2004 the media wrote about Radio source SHGb02+14a and its artificial origin, but scrutiny has not been able to confirm its connection with an extraterrestrial civilization.[6] Currently no confirmed extraterrestrial signals have been found.[7]
