Underwater communication method, device, and system utilizing a doppler frequency shift

An electronic underwater device for receiving an acoustical signal transmitted by a transmitter and for determining a location of the transmitter, the transmitted acoustical signal having a predetermined transmit frequency, said device comprising:

• an acoustical receiver for receiving the transmitted acoustical signal;
• a processor coupled to said acoustical receiver for receiving input therefrom and including a frequency detector for detecting a receive frequency of the received acoustical signal, said processor including means for determining a frequency shift between the receive frequency and the predetermined transmit frequency;
• a detector coupled to said processor and for determining an angular orientation of said device relative to a fixed point;
• and
• a display coupled to said processor;
• said device further comprising means for locating the transmitter based on the determined frequency shift between the received frequency and the predetermined transmit frequency and based on the angular orientation of said device, said device also comprising means for displaying on said display an indication of the location of the transmitter relative to said device.

An electronic underwater device for receiving an acoustical signal transmitted by a transmitter and having a predetermined transmit frequency, said device comprising:

• an acoustical receiver for receiving the transmitted acoustical signal;
• a processor coupled to said acoustical receiver for receiving input therefrom and including means for determining whether the received acoustical signal is a message signal or a locating signal;
• a detector coupled to said processor and for determining an angular orientation of said device relative to a fixed point;
• and
• a display coupled to said processor;
• said processor including a frequency detector and, when said processor determines that the received acoustical signal is a locating signal, said frequency detector detecting a frequency of the received acoustical signal and said processor including means for determining a frequency shift between the frequency of the received acoustical signal and the predetermined transmit frequency, said device further comprising means for determining a location of the transmitter based on the determined frequency shift between the received frequency and the predetermined transmit frequency and based on the angular orientation of said device, said device also comprising means for causing said display to display an indication of the location of the transmitter relative to said device;
• said processor including memory within which is stored a plurality of message identification codes corresponding to a plurality of predetermined textual messages, when said processor determines that the received acoustical signal is a message signal, said processor including means for determining a message code in the received acoustical signal and means for determining a textual message corresponding to the received message code, said device further comprising means for causing said display to display said corresponding textual message.

An electronic underwater device for transmitting an acoustical signal having a predetermined transmit frequency for reception by a user selected receiving device, and for receiving an acoustical signal transmitted by a remote transmitter and having a predetermined receive frequency, said device comprising:

• a hydrophone for transmitting and receiving an acoustical signal;
• a processor coupled to said hydrophone for providing output thereto and for receiving input therefrom, said processor including a frequency detector for detecting a receive frequency of the received acoustical signal, said processor including means for determining a frequency shift between the receive frequency and the predetermined transmit frequency;
• a detector coupled to said processor and for determining an angular orientation of said device relative to a fixed point;
• and
• a display coupled to said processor;
• said device further comprising means for locating the remote transmitter based on the determined frequency shift between the received frequency and the predetermined receive frequency and based on the angular orientation of said device, said device also comprising means for displaying on said display an indication of the location of the remote transmitter relative to said device.

An electronic underwater device comprising:

• an acoustical transmitter and receiver;
• a processor coupled to said acoustical transmitter and receiver and comprising:
• a transmitter for generating and transmitting an acoustical signal;
• a receiver for receiving an acoustical signal transmitted by a remote transmitter;
• means for determining if a received acoustical signal is a message signal or a locating signal;
• an angular detector coupled to said processor and for determining an angular orientation of said device relative to a fixed point;
• a display coupled to said processor;
• a frequency detector for detecting a frequency of a received locating signal having a predetermined receive frequency;
• and
• means for determining a frequency shift between the frequency of the received locating signal and the predetermined receive frequency;
• when said processor determines that the received acoustical signal is a message signal, said processor causing said display to display a predetermined textual message transmitted as the acoustical signal by the remote transmitter;
• when said processor determines that the received acoustical signal is a locating signal, said device determining a location of the remote transmitter based on the determined frequency shift between the received frequency of the locating signal and the predetermined receive frequency and based on the angular orientation of said device, said device further comprising means for causing said display to display an indication of the location of the remote transmitter relative to said device.

An underwater communication network comprising a plurality of underwater communication devices, each of said devices comprising:

• an acoustical transmitter and receiver;
• a processor coupled to said acoustical transmitter and receiver and comprising:
• a transmitter for generating and transmitting an acoustical signal;
• a receiver for receiving an acoustical signal transmitted by a remote transmitter;
• means for determining if a received acoustical signal is a message signal or a locating signal;
• an angular detector coupled to said processor and for determining an angular orientation of said device relative to a fixed point;
• a display coupled to said processor;
• a frequency detector for detecting a frequency of a received locating signal having a predetermined receive frequency;
• and
• means for determining a frequency shift between the frequency of the received locating signal and the predetermined receive frequency;
• when said processor determines that the received acoustical signal is a message signal, said processor causing said display to display a predetermined textual message transmitted as the acoustical signal by the remote transmitter;
• when said processor determines that the received acoustical signal is a locating signal, said device determining a location of the remote transmitter based on the determined frequency shift between the received frequency of the locating signal and the predetermined receive frequency and based on the angular orientation of said device, said device further comprising means for causing said display to display an indication of the location of the remote transmitter relative to each said device.

An electronic underwater communication device for transmitting an acoustical signal and for receiving an acoustical signal from another underwater communication device, said device comprising:

• means for transmitting an acoustical signal having a predetermined frequency;
• means for receiving an acoustical signal having a receive signal frequency from the another underwater communication device;
• means for detecting the receive signal frequency;
• means for determining a frequency shift between the receive signal frequency and a predetermined receive signal frequency;
• means for determining an angular orientation of said device relative to a fixed point;
• and
• means for locating the another underwater communication device based on the determined frequency shift between the receive signal frequency and the predetermined receive signal frequency and based on the angular orientation of said device.

A personal underwater communication device comprising:

• a display;
• memory for storing a plurality of messages, each message being assigned a unique message identification code;
• a detector for determining an angular orientation of said device relative to a fixed point;
• means for selecting one of said messages for transmission by said device and for selecting a receiving device to which a selected message is to be transmitted;
• means for producing a string encoding said message identification code, a unique identification code of the transmitting device, and a unique identification code of the user selected receiving device;
• means for modulating said string with a predetermined transmit frequency to produce a modulated signal;
• means for transmitting said modulated signal as an acoustical signal, and for receiving an acoustical signal having a predetermined receive frequency and transmitted by a transmitter;
• means for detecting a frequency of a received acoustical signal;
• means for determining a frequency shift between the frequency of the received acoustical signal and the predetermined receive frequency;
• means for determining if a received acoustical signal is a message signal or a locating signal;
• when said device determines that the received acoustical signal is a locating signal, said detecting means detecting a frequency of the received acoustical signal and said device determining a location of the transmitter based on the determined frequency shift between the received frequency and the predetermined transmit frequency and based on the angular orientation of said device, said device also displaying on said display an indication of the location of the transmitter relative to said device;
• when said device determines that the received acoustical signal is a message signal, said device determining a unique message identification code in the received acoustical signal and determining a textual message corresponding to the received unique message identification code, said device displaying on said display said corresponding textual message.