The fast Fourier transform spectrometer is a filter that can be put on the receiver or a radio telescope to extract distinctive short signals from radio noise.
The observational opportunities opened up by the fast Fourier transform range from detection of microwave pulses from X-ray sources and the study of pulsars to gaining first observational evidence of that long sought and exotic outcome of the theory of relativity, a black hole. The first fast Fourier transform spectrometer applied to radio astronomy was built by Joseph Erkes and Ivan Linscott of the Dudley Observatory, and electrical engineer Noble Powell of GE. In 1978, it was used on the Arecibo, Puerto Rico, radio telescope to detect signals from the galaxy M87 that gave possible evidence of a black hole. Published as “Discovery of Multisecond Bursts from M87” in the Astrophysical Journal, 236 (1980), L109, this research launched the now important field of using very fast special purpose computers to analyze radio astronomy signals, today an important tool of radio astronomers.