The Multisite and Multifrequency Simultaneous SETI Observation in Japan

It is thought that a narrow carrier signal is the most possible kind of signal from an Extra-Terrestrial Intelligence (ETI), because it needs only one parameter "frequency". Therefore, it may be a possibility that other types of signals are used to inform their existence. For example, an Ultra-Wide Band (UWB) signal is one of the possible signals, because generally it is advantageous on the standpoint of signal to noise ratio as shown by the Global Positioning System. We carried out multisite and multi-frequency SETI observations based on similar idea. We also did the multi-site optical monitoring observations simultaneously. If radio antennas detect the candidate signals, we check these optical (CCD, Digital camera and Video) images. It gives a clue of clarification of radio events {e.g. natural phenomenon (flare of surface of the star, nova, GRB, meteor, microlens etc.), artificial signals (aircraft, artificial satellite, reflection off space debris etc.) and ETI}. This is the world's first multi-site and multi-wavelength simultaneous SETI observation with 12 radio and 26 optical systems in Japan. World's first multi-site and multi-wavelength simultaneous SETI observation. Detected radio signals were checked by optical images. Strategy: UWB signals may be used by ETI as narrow carrier signals have not yet yielded information. Data under reduction. No radio or optical candidate signals were detected.