Radio SETI    updated October 3, 2005  D. Carrigan carrigan@fnal.gov (subject line must be sensible)

Radio signal propagation (see SETI fomulas)

Some other radio SETI  sites:

Energy to launch an electromagnetic bit, transmit it through space, and detect it

• Larger separation between the sender and receiver requires more energy

• Bigger transmitting and receiving antennas lower the energy

• Better or more sensitive detectors help. For fundamental reasons this implies cold detectors.

• For electromagnetic signals the attenuation of the interstellar medium is important

• Antenna gain-the ability of an antenna to focus the beam. Bigger dishes with higher gain focus better

• For the example in the left hand column the transmitter cost of a received electromagnetic bit is 4 Joules

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