Encoded echo-ranging signal generator

• US 3,958,214 A
• Filed: 07/19/1963
• Issued: 05/18/1976
• Est. Priority Date: 07/19/1963
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Andrews, Daniel E. Jr., Klund, William E., Isaak, Robert D.
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US04/296,413
• Time in Patent Office: 4,687 Days
• Field of Search: 178/22, 331/78, 328/37, 328/43, 343/17.1, 325/32, 325/122, 340/3 A, 340/5 R
• US Class Current: 367/137
• CPC Class Codes: G01S 15/87 Combinations of sonar systems
• CPC Class Codes: H04K 1/02 by adding a second signal to make the desired signal unintelligible

Abstract

1. An encoded echo-ranging signal generator comprising in combination;

A digital shift register having a plurality of binary encoded stages,

A shift pulse generator coupled to said digital shift register for the tiy shifting thereof,

An anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said digital shaft register and the other input thereof coupled to the output of said digital shift register and with the output thereof connected to the input of said digital shaft register, to randomly recirculate through said register the binary contents of said encoded stages,

An echo-ranging system coupled to the output of said digital shift register,

And a digital message encoder coupled to said digital shift register for the respective binary bit encoding of each stage thereof.

Claims

1. An encoded echo-ranging signal generator comprising in combination;

a digital shift register having a plurality of binary encoded stages,

a shift pulse generator coupled to said digital shift register for the timely shifting thereof,

an anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said digital shift register and the other input thereof coupled to the output of said digital shift register and with the output thereof connected to the input of said digital shift register, to randomly recirculate through said register the binary contents of said encoded stages,

an echo-ranging system coupled to the output of said digital shift register,

and a digital message encoder coupled to said digital shift register for the respective binary bit encoding of each stage thereof.

2. An encoded echo-ranging signal generator comprising in combination,

a first digital shift register having a plurality of binary encoded stages,

a first anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said first digital shift register and the other input thereof coupled to the output of said first digital shift register and with the output thereof connected to the input of said first digital shift register,

a second digital shift register having a plurality of binary encoded stages,

a second anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said second digital shift register and the other input thereof coupled to the output of said second digital shift register and with the output thereof connected to the input of said second digital shift register,

a shift pulse generator coupled to each of said first and second digital shift registers for the timely shifting thereof, and

a summing network having a pair of inputs and an output with said pair of inputs respectively coupled to the outputs of said first and second digital shift registers.

3. The device of claim 2 wherein said first and second anti-coincidence circuits each comprise;

a first inverter,

a second inverter,

a first AND gate having a pair of inputs one of which is coupled to the output of said first inverter,

a second AND gate having a pair of inputs one of which is coupled to the output of said second inverter, and

an OR circuit having a pair of inputs and an output with said pair of inputs respectively connected to the outputs of said first and second AND gates.

4. An encoded echo-ranging signal generator comprising in combination;

a first digital shift register having a plurality of binary encoded stages,

a first anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said first digital shift register and the other input thereof coupled to the output of said first digital shift register and with the output thereof connected to the input of said first digital shift register,

a second digital shift register having a plurality of binary encoded stages,

a second anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said second digital shift register and the other input thereof coupled to the output of said second digital shift register and with the output thereof connected to the input of said second digital shift register,

a shift pulse generator coupled to each of said first and second digital shift pulse generators for the timely shifting thereof, and

a summing network having a pair of inputs and an output with said pair of inputs respectively coupled to the outputs of said first and second digital shift registers,

a first digital message encoder coupled to said first digital shift register for binary bit encoding of each stage thereof, and

a second digital message encoder coupled to said second digital shift register for binary bit encoding of each stage thereof.

5. An encoded echo-ranging signal generator comprising in combination;

a first digital shift register having a plurality of binary encoded stages,

a first anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said first digital shift register and the other input thereof coupled to the output of said first digital shift register and with the output thereof connected to the input of said first digital shift register,

a second digital shift register having a plurality of binary encoded stages,

a second anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said second digital shift register and the other input thereof coupled to the output of said second digital shift register and with the output thereof connected to the input of said second digital shift register,

a shift pulse generator coupled to each of said first and second digital shift pulse generators for the timely shifting thereof,

a summing network having a pair of inputs and an output with said pair of inputs respectively coupled to the outputs of said first and second digital shift registers, and

an echo-ranging system connected to the output of the aforesaid summing network.

6. The device of claim 5 wherein said echo-ranging system connected to the output of the aforesaid summing network comprises;

a bandpass filter,

a transmitter coupled to the output of said bandpass filter, and

a transducer connected to the output of the aforesaid transmitter.

7. An encoded echo-ranging signal generator comprising in combination;

a first digital shift register having a plurality of binary encoded stages,

a first anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said first digital shift register and the other input thereof coupled to the output of said first digital shift register and with the output thereof connected to the input of said first digital shift register,

a second digital shift register having a plurality of binary encoded stages,

a second anti-coincidence circuit having a pair of inputs and an output with one of said inputs being connected to a predetermined stage of said second digital shift register and the other input thereof coupled to the output of said second digital shift register and with the output thereof connected to the input of said second digital shift register,

a shift pulse generator coupled to each of said first and second digital shift pulse generators for the timely shifting thereof,

a summing network having a pair of inputs and an output with said pair of inputs respectively coupled to the outputs of said first and second digital shift registers,

a first digital message encoder coupled to said first digital shift register for binary bit encoding of each stage thereof,

a second digital message encoder coupled to said second digital shift register for binary bit encoding of each stage thereof, and

an echo-ranging system connected to the output of the aforesaid summing network.

8. The device of claim 7 wherein said echo-ranging system connected to the output of the aforesaid summing network comprises;

a filter,

a sonar transmitter coupled to the output of said filter, and

a sonar transducer connected to the output of said sonar transmitter.

9. A cryptographic signal generator comprising in combination;

means for sequentially shifting a pre-stored plurality of binary bits,

a recirculating feedback system including logic means connected to said binary bit shifting means for predetermining which stored binary bit is to be fed back as the input thereto,

means coupled to said binary bit shifting means for timely effecting the shifting thereof,

means connected to said shifting means for programming the plurality of binary bits pre-stored therein, and

means connected to the output of said shifting means for broadcasting the output signals shifted therefrom throughout a predetermined environmental medium.

10. The device of claim 9 wherein said means connected to the output of said shifting means for broadcasting the output signals shifted therefrom throughout a predetermined environmental medium comprises;

a bandpass filter,

a transmitter coupled to the output of said bandpass filter, and

a transducer connected to the output of said transmitter.

11. An encoded signal generator comprising in combination;

a digital shift register having a predetermined plurality of stages for respectively storing a like plurality of programmed binary bits therein,

means for loading a plurality of programmed binary bits respectively in the plurality of stages of said digital shift register for storage thereof in accordance with a cryptographic code,

a first inverter connected to the output of a predetermined one of said plurality of stages of the aforesaid digital shift register,

a second inverter connected to the output of the last stage of the aforesaid digital shift register,

a first AND gate having a pair of inputs and an output with one of the inputs thereof coupled to the output of said first inverter and the other input thereof coupled to the output of said last stage of said plurality of stages of the aforesaid digital shift register,

a second AND gate having a pair of inputs and an output with one of the inputs thereof coupled to the output of said second inverter and the other output thereof coupled to the output of said one predetermined stage of said plurality of stages of the aforesaid digital shift register,

an OR circuit having a pair of inputs and an output with one of the inputs thereof coupled to the output of said first AND gate and the other input thereof coupled to the output of said second AND gate and the output thereof connected to the input of the aforesaid digital shift register, and

a shift pulse generator connected to said digital shift register for the timely shifting thereof.

12. The device of claim 11 wherein said means for loading a plurality of programmed binary bits respectively in the plurality of stages of said digital shift register for storage thereof in accordance with a cryptographic code comprises a plurality of digital message encoders.

13. The invention according to claim 11 further characterized by an echo-ranging system coupled to the aforesaid digital shift register for effectively broadcasting the output therefrom throughout a predetermined subaqueous medium.

14. An encoded echo-ranging signal generator comprising in combination,

shift register means having a plurality of stages for respectively storing predetermined binary bits therein,

means coupled to said shift register means for respectively loading programmed binary bits in each of the plurality of stages thereof,

anti-coincidence means connected to said shift register means for appropriately feeding back predetermined binary bits from predetermined outputs thereof to the input thereof,

means connected to said shift register means for the timely shifting thereof, and

means connected to the output of the aforesaid shift register means for effectively transmitting the output therefrom throughout a predetermined environmental medium.

15. An encoded echo-ranging signal generator comprising in combination;

a plurality of digital shift registers each of which has a predetermined plurality of stages for respectively storing a like plurality of binary bits,

a plurality of binary programming means respectively connected to said plurality of digital shift registers for timely and respectively loading the stages thereof with predetermined programmed sets of binary bits,

a plurality of anti-coincidence logic means each of which has a pair of inputs and an output with one of said inputs of each thereof respectively connected to a predetermined one of the stages of said plurality of digital shift registers and the other input of each thereof respectively connected to the outputs of said plurality of digital shift registers and with the outputs thereof respectively coupled to the inputs of said plurality of digital shift registers,

means connected to each of said plurality of digital shift registers for shifting same at a predetermined shifting rate, and means connected to the output of the aforesaid shift register means for broadcasting the outputs of said registers through a predetermined environmental medium.

16. The invention according to claim 15 further characterized by a summing network connected to the output of each of said plurality of digital shift registers.

17. The device of claim 16 further characterized by an echo-ranging system connected to said summing network for effectively broadcasting the output therefrom throughout a predetermined environmental medium.

18. A digital message encoder comprising in combination;

means for generating a pulse whose length represents a predetermined message,

means for producing a signal of predetermined frequency,

gating means coupled to the outputs of said pulse generating and signal producing means for producing a plurality of shift pulses when the inputs thereto are coincidental,

a multi-stage encoder digital shift register coupled to the output of said gating means for shifting by said plurality of shift pulses,

an anti-coincidence circuit coupled to said encoder digital shift register in such manner as to timely recirculate outputs therefrom as feedback input signals thereto for providing continuous output signals therefrom,

a plurality of AND gates having a pair of inputs and an output with one of the inputs of each thereof respectively connected to each of the stages of said multistage encoder digital shift register and the outputs thereof adapted for being respectively connected to each of the stages of a transmitting digital shift register, and

a transfer pulse generator interconnecting the output of said message representing pulse generating means and the other input to each of the aforesaid plurality of AND gates.

19. The device of claim 18 wherein said means for generating a pulse whose length represents a predetermined message comprises:

means for receiving a start pulse,

a counter coupled to said start pulse receiving means,

a pattern detector coupled to the output of said counter, and

a flip-flop having a pair of inputs and an output with one of the inputs coupled to the output of said pattern detector and the other input thereof connected to the aforesaid start pulse receiving means.

20. The invention according to claim 19 further characterized by;

a second plurality of AND gates each of which has a pair of inputs and an output with one of the inputs of each thereof connected to said start pulse receiving means and the other input of each thereof adapted for being respectively connected to the stages of a second transmitting digital shift register and the outputs thereof respectively connected to each of the stages of said first mentioned transmitted digital shift register.