Submerged sensing system using line array segments

Abstract

An underwater sensing system has a trunk cable that transmits a plurality clock signals from its first end to its second end. A plurality of signal handling nodes are installed successively along the trunk cable in a spaced apart relationship. Each of a plurality of linear sensor arrays extend from one signal handling node. Each sensor in the sensor arrays receives the clock signals and generates a data output signal in response thereto at specifically ordered time sampled intervals based on a count of the clock signals. The data output signals are transmitted to the one signal handling node associated with the sensor array. At each of the signal handling nodes, a multiplexer interleaves the data output signals received from its sensor array in a continual throughput, time-division multiplexed fashion with concatenated data output signals received from the next successive signal handling node located further from the first end of the trunk cable.

What is claimed as new and desired to be secured by Letters Patent of the United States is: 
     
       1. An underwater sensing system, comprising: a trunk cable for transmission of a plurality of clock signals from a first end to a second end of said trunk cable;   a plurality of signal handling nodes connected to said trunk cable in a spaced apart relationship, wherein each successive one of said plurality of signal handling nodes is located further from said first end of said trunk cable than a preceding one of said plurality of signal handling nodes;   a plurality of sensor arrays, each of said plurality of sensor arrays connected to and extending from a corresponding one of said plurality of signal handling nodes, each of said plurality of sensor arrays connecting a plurality of sensors that generate a data output signal in response to said plurality of clock signals, wherein each said data output signal passes to said corresponding one of said plurality of signal handling nodes; and   each said plurality of signal handling nodes including a multiplexer connected to said trunk cable and a corresponding one of said plurality of sensor arrays, for interleaving each said data output signal received from said corresponding one of said plurality of sensor arrays in a continual throughput time orderly fashion with concatenated data output signals received over said trunk cable from said successive one of said plurality of signal handling nodes.   
     
     
       2. A system as in claim 1 further including a flotation system connected to said plurality of sensor arrays for buoyantly extending each of said plurality of sensor arrays from said trunk cable in a substantially vertical direction. 
     
     
       3. A system as in claim 1 further including an anchor system for securing said trunk cable to a sea floor. 
     
     
       4. A system as in claim 3 further including floats connected to said plurality of sensor arrays for buoyantly extending each of said plurality of sensor arrays upward from said trunk cable in a substantially vertical direction. 
     
     
       5. A system as in claim 1 further including weights connected to said plurality of sensor arrays for maintaining each of said plurality of sensor arrays in a substantially horizontal direction extending along said sea floor. 
     
     
       6. A system as in claim 1 wherein each of said plurality of sensor arrays is a linear sensor array. 
     
     
       7. A system as in claim 1 wherein each said sensor further includes a sampling circuit for counting said plurality of clock signals and for sampling each said sensor's response after a predetermined number of clock signals are counted from said plurality of clock signals, wherein said predetermined number for each said sensor is based upon each said sensor's relative proximity to said corresponding one of said plurality of signal handling nodes. 
     
     
       8. A system as in claim 1 wherein each of said plurality of signal handling nodes further includes an analog-to-digital converter for converting each said data output signal received from said one of said plurality of sensor arrays from an analog to a digital format, said analog-to-digital converter outputting each said data output signal in said digital format to said multiplexer located at each of said plurality of signal handling nodes. 
     
     
       9. A system as in claim 1 wherein said plurality of signal handling nodes are electrically connected to said trunk cable, wherein each of said plurality of sensor arrays are electrically connected to said corresponding one of said plurality of signal handling nodes, wherein each of said plurality of sensor arrays electrically connects said plurality of sensors, and wherein each said multiplexer is electrically connected to said trunk cable and said corresponding one of said plurality of sensor arrays. 
     
     
       10. An underwater acoustic sensing system, comprising: a trunk cable for transmission of a plurality of clock signals from a first end to a second end of said trunk cable;   a plurality of signal handling nodes electrically connected to said trunk cable in a spaced apart relationship, wherein each successive one of said plurality of signal handling nodes is located further from said first end of said trunk cable;   a plurality of electrically conducting array cables, each of said plurality of array cables extending from a corresponding one of said plurality of signal handling nodes and each of said plurality of array cables electrically connected to said trunk cable at said corresponding one of said plurality of signal handling nodes;   a plurality of hydrophone assemblies installed along and electrically connected to each of said plurality of array cables in a spaced apart relationship for receiving said plurality of clock signals, wherein each of said plurality of hydrophone assemblies generates an output signal indicative of an acoustic pressure impinging thereon in response to said plurality of clock signals, and each said output signal passes on a corresponding one of said plurality of array cables to said corresponding one of said plurality of signal handling nodes; and   each of said plurality of signal handling nodes including a multiplexer electrically connected to said trunk cable and to said corresponding one of said plurality of array cables, for interleaving each said output signal received from said corresponding one of said plurality of array cables in a continual throughput, time-division multiplexing fashion with concatenated output signals received over said trunk cable from said successive one of said plurality of signal handling nodes.   
     
     
       11. A system as in claim 10 further including an anchor system for securing said trunk cable to a sea floor. 
     
     
       12. A system as in claim 11 further including floats connected to said plurality of array cables for buoyantly extending each of said plurality of array cables upward from said trunk cable in a substantially vertical direction. 
     
     
       13. A system as in claim 11 further including weights connected to said plurality of array cables for maintaining each of said plurality of array cables in a substantially horizontal direction extending along said sea floor. 
     
     
       14. A system as in claim 10 wherein each of said plurality of array cables is a linear array cable. 
     
     
       15. A system as in claim 10 wherein each of said plurality of hydrophone assemblies includes a sampling circuit for counting said plurality of clock signals and for sampling each of said plurality of hydrophone assemblies after a predetermined number of clock signals are counted from said plurality of clock signals, wherein said predetermined number for each of said plurality of hydrophone assemblies is based upon each of said plurality of hydrophone assemblies relative proximity to said corresponding one of said plurality of signal handling nodes. 
     
     
       16. A system as in claim 10 wherein each of said plurality of signal handling nodes further includes an analog-to-digital converter for converting each said output signal received from said corresponding one of said plurality of array cables from an analog to a digital format, said analog-to-digital converter outputting each said output signal in said digital format to said multiplexer located at each of said plurality of signal handling nodes. 
     
     
       17. An underwater acoustic sensing system, comprising: a trunk cable including first and second electronic signal transmission wires, said first wire for transmission of control commands and a plurality of clock signals from a first end to a second end of said trunk cable;   a plurality of signal handling nodes installed successively along said trunk cable in a spaced apart relationship, each of said plurality of signal handling nodes electrically connected to said first and second wires, wherein each successive one of said plurality of signal handling nodes is located further from said first end of said trunk cable than a preceding one of said plurality of signal handling nodes;   a plurality of array cables, each of said plurality of array cables including corresponding third and fourth electronic signal transmission wires, each of said plurality of array cables having a fixed end anchored to a corresponding one of said plurality of signal handling nodes and having a free-floating end;   a plurality of hydrophone assemblies installed along each of said plurality of array cables in a spaced apart relationship, each said plurality of hydrophone assemblies being further electrically connected to said corresponding third and fourth wires for receiving said control commands and said plurality of clock signals on said corresponding third wire, wherein individual ones of each said plurality of hydrophone assemblies activated by said control commands generate an output signal indicative of an acoustic pressure impinging thereon in response to said plurality of clock signals;   a sampling circuit associated with said individual ones of each said plurality of hydrophone assemblies for counting said plurality of clock signals and for sampling said individual ones after a predetermined number of clock signals are counted from said plurality of clock signals, wherein said predetermined number for each said individual ones is based upon each said individual ones relative proximity to said corresponding one of said plurality of signal handling nodes, and wherein each said output signal is passed to said corresponding one of said plurality of signal handling nodes via said corresponding fourth wire; and   each of said plurality of signal handling nodes including a multiplexer electrically connected to said first, second and corresponding fourth wires, each said multiplexer receiving said clock signal and interleaving each said output signal that is delayed and passed on said corresponding fourth wire in a continual throughput, time-division multiplexing fashion with concatenated output signals received over said second wire from said successive one of said plurality of signal handling nodes.   
     
     
       18. A system as in claim 17 further including an anchor system for securing said trunk cable to a sea floor. 
     
     
       19. A system as in claim 18 further including floats connected to each said free-floating end of said plurality of array cables for buoyantly extending each of said plurality of array cables upward from said trunk cable in a substantially vertical direction. 
     
     
       20. A system as in claim 18 further including weights connected to each said free-floating end of said plurality of array cables for maintaining of each of said array cables in a substantially horizontal direction extending along said sea floor. 
     
     
       21. A system as in claim 17 wherein each of said plurality of array cables is a linear array cable. 
     
     
       22. A system as in claim 17 wherein each of said plurality of signal handling nodes further includes an analog-to-digital converter for converting each said output signal received on said corresponding fourth wire from an analog to a digital format, said analog-to-digital converter outputting each said output signal in said digital format to said multiplexer located at each of said plurality of signal handling nodes. 
     
     
       23. A system as in claim 17 wherein said predetermined number increases for each successive one of each said plurality of hydrophone assemblies located further from each said fixed end of each of said plurality of array cables. 
     
     
       24. A system as in claim 17 wherein said predetermined number increases an equal amount for each successive one of each said plurality of hydrophone assemblies located further from each said fixed end of each of said plurality of array cables.