释义 |
DictionarySeecommunications satellitespot beam
spot beam[′spät ‚bēm] (communications) A beam generated by a communications satellite antenna of sufficient size that the angular spread of energy in the beam is small, always smaller than the earth's angular beam width as seen from the satellite. spot beamA communications satellite signal that transmits to a pinpointed geographic area on earth. Spot beam technology allows different data to be sent to different locations using the same carrier frequencies. For example, local TV programs can be transmitted to multiple counties within a state; however, the beam footprint is naturally circular and cannot correspond to local jurisdictions. See communications satellite. |