04547778 is referenced by 54 patents and cites 8 patents.

A method and apparatus for determining the position of a vessel in distress and transmitting an auditory distress message containing the position of the vessel. The apparatus obtains the position of the vessel as determined by a LORAN-C type receiver from either a cassette or directly from the LORAN-C receiver and generates a "Mayday" message including the identification of a vessel, the position of the vessel and the nature of the emergency. The "Mayday" message is synthesized into an auditory human or Morse code message. The language of the auditory message is preferably chosen to correspond with the most likely language used by a possible receiver of the "Mayday" message. Also preferably, the apparatus determines whether the primary distress radio frequency is clear; should the primary distress frequency be in use, the apparatus automatically shifts to a secondary frequency and transmits the "Mayday" message. During transmission on the secondary frequency the apparatus continues to monitor primary frequency; when the primary frequency clears, the "Mayday" message is transmitted thereon.

Title
Method and apparatus for automatic distress call signal transmission
Application Number
6/271915
Publication Number
4547778
Application Date
June 9, 1981
Publication Date
October 15, 1985
Inventor
Michael O Hagan
Dallas
TX, US
Robert W Hinkle
Dallas
TX, US
Agent
Melvin Sharp
Leo N Heiting
Alva H Bandy
Assignee
Texas Instruments Incorporated
TX, US
IPC
G01S 3/02
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