Method for correlating frequency-modulated signals

• US 3,903,407 A
• Filed: 12/11/1963
• Issued: 09/02/1975
• Est. Priority Date: 12/11/1963
• Status: Expired due to Term

• Current Assignee: Bradshaw Burnham
• Original Assignee: Bradshaw Burnham
• Inventors: Burnham, Bradshaw
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US04/329,932
• Time in Patent Office: 4,283 Days
• Field of Search: 343/5MM,5PR,17,100.7 340/15.5C 346/107 235/181 350/161
• US Class Current: 708/816
• CPC Class Codes: G06E 3/003 forming integrals of products, e.g. Fourier integrals, Laplace integrals, correlation integrals; for analysis or synthesis of functions using orthogonal functions

Abstract

Apparatus and method for correlating frequency-modulated signal wavetrains with their return signal wavetrains which includes compensating for delay distortions in the signal while passing through a medium. Correlation is accomplished by photo-optical apparatus.

Claims

1. A method for correlating frequency-modulated signal wavetrains with their return-signal wavetrains after propagation through a distorting medium comprising the steps of:

generating a frequency-modulated, repeatable series of electrical undulations known as the '"'"''"'"''"'"''"'"'original reference function'"'"''"'"''"'"''"'"';

transmitting said original reference function through a medium after passing it through suitable transmitting electronic equipment to prepare it for transmission through such a medium;

receiving the transmitted signal and passing it through suitable receiving electronic equipment to derive a medium-andequipment-distorted signal therefrom;

passing said original reference function through means which simulate the transfer function of the transmitting and receiving electronic equipment through which said original reference function has passed and through means which simulate the transfer function of said medium according to the range in the medium over which the signal has been propagated, the final signal being known as the '"'"''"'"''"'"''"'"'evolved reference function'"'"''"'"''"'"''"'"';

making a record of the evolved reference function; and

correlating the medium-and-equipment-distorted signal with the evolved reference function.

2. A method for correlating frequency-modulated signal wavetrains with their return-signal wavetrains after propagation through a distorting medium comprising the steps of:

generating a frequency-modulated, repeatable series of electrical undulations known as the '"'"''"'"''"'"''"'"'original reference function'"'"''"'"''"'"''"'"';

transmitting said original reference function through a medium after passing it through suitable transmitting electronic equipment to prepare it for transmission through such a medium;

receiving the transmitted signal and passing it through suitable receiving electronic equipment to derive a medium-and-equipment-distorted signal therefrom;

passing said original reference function through means which simulate the transfer function of the transmitting and receiving electronic equipment through which said original reference function has passed and through means which simulate the transfer function of said medium according to the range in the medium over which the signal has been propagated, the final signal being known as the '"'"''"'"''"'"''"'"'evolved reference function'"'"''"'"''"'"''"'"';

making a record of the evolved reference function, said record comprising the analog of a series of evolved reference functions, each succeeding one being for a greater range than the previous one; and

correlating the medium-and-equipment-distorted signal with the evolved reference function.

3. A method for correlating frequency-modulated signal wavetrains with their return-signal wavetrains after propagation through a distorting medium comprising the steps of:

generating a frequency-modulated, repeatable series of electrical undulations known as the '"'"''"'"''"'"''"'"'original reference function'"'"''"'"''"'"''"'"';

transmitting said original reference function through a medium after passing it through suitable transmitting electronic equipment to prepare it for transmission through such a medium;

receiving the transmitted signal and passing it through suitable receiving electronic equipment to derive a medium-and-equipment-distorted signal therefrom;

passing said original reference function through means which simulate the transfer function of the transmitting and receiving electronic equipment through which said original reference function has passed and through means which simulate the transfer function of said medium according to the range in the medium over which the signal has been propagated, the final signal being known as the '"'"''"'"''"'"''"'"'evolved reference function'"'"''"'"''"'"''"'"';

making a record of the evolved reference function, said record comprising the analog of a series of evolved reference functions, each succeeding one being for a greater range than the previous one, said record being made on a continuous loop of recording material; and

correlating the medium-and-equipment-distorted signal with the evolved reference function.