Object location system

Claim 2

Apparatus for locating a source of radiations through ambient noise of substantial strength, which comprises at least two transducers, spaced apart, means individual to each of said transducers for continuously recording its output on a recording medium, means for rapidly and repeatedly scanning each of said recording media to derive a time signal which is expanded in frequency and compressed in time as compared with that of said source, means for variously delaying one of said time signals relatively to the other, means for comparing said time signals for various values of said delay, means for deriving from said comparing means a measure of the degree of similarity of said time signals, whereby said measure reaches an extreme value when said time signals are coincident in time, and means for indicating the magnitude of said relative delay for which said measure attains said extreme value.

Claim 3

Apparatus as defined in claim 1 wherein each of said recording media comprises a magnetically sensitive medium formed into an endless loop, and said recording means includes a recording element and an erasing element juxtaposed with said loop, and means for rotating said loop past said elements.

Claim 4

Apparatus as defined in claim 1 wherein said delaying means comprises a wave propagation device having a plurality of lateral taps and means for collecting the signals appearing at said taps in ordered succession for applying them to a common point.

Claim 5

Apparatus as defined in claim 1 wherein said delaying means comprises means for varying the phase of the scanning of one of said recording media as compared with the phase of the scanning of the other of said recording media.

Claim 6

Apparatus as defined in claim 1 wherein said delaying means comprises means for varying the space phase of one of said scanning means relative to that of the other.

Claim 7

Apparatus as defined in claim 2 wherein said delaying means comprises means for varying the space phase of one of said endless loops in the course of its rotation as compared with the space phase of the other of said endless loops in the course of its rotation.

Claim 8

In combination with apparatus as defined in claim 2, means for recurrently disabling said degree of similarity deriving means throughout an interval which includes the entire interval during which the scanning means deriving said time signal from one of said magnetic loops lies between the recording element and the erasing element which are juxtaposed with the endless loop.

Claim 9

In combination with apparatus as defined in claim 1, a first modulator having a first input point connected to one of said transducers and an output point connected to one of said recording means, a second modulator having a first input point connected to another of said transducers and an output point connected to another of said recording means, each of said modulators having also a second input point, and a source of carrier frequency oscillations connected to the second input point of each of said modulators.

Claim 10

Apparatus as defined in claim 1 wherein said comparing means comprises means for multiplying said time signals together to form a product.

Claim 11

Apparatus as defined in claim 1 wherein said comparing means comprises means for multiplying said time signals together to form a product and means for integrating said product over a time substantially equal to the time for a single traversal of one of said recording media by one of said rapid scanning means.

Claim 12

Apparatus for locating a source of radiations through ambient noise of substantial strength which comprises a first plurality of transducers spaced apart by distances L1 along a first base line, a second plurality of transducers spaced apart by distances L2 along a second base line, each of said pluralities comprising an array, said arrays being spaced apart by a distance L3 along a third base line, means connected to each of said transducers for equalizing the wave propagation path lengths from said source to the outputs of the individual ones of said equalizing means of each of said arrays, means for combining the outputs of the several ones of said equalizing means connected to the transducers of said first array to form a first combined output, means for combining the outputs of the several one of said equalizing means connected to the transducers of said second array to form a second combined output, means for variously delaying one of said combined outputs with respect to the other combined output, means for comparing one of said combined outputs with the other combined output, and means for indicating the magnitude of said delay for which said comparison indicates maximum similarity between said combined outputs.

Claim 13

Apparatus for locating a source of radiations through ambient noise of substantial strength which comprises a first plurality of transducers spaced apart by distances L1 along a first base line, a second plurality of transducers spaced apart by distances L2 along a second base line, each of said pluralities comprising an array, said arrays being spaced apart by a distance L3 along a third base line, means connected to each of said transducers for equalizing the wave propagation path lengths from said source to the outputs of the individual ones of said equalizing means of each of said arrays, means for combining the outputs of the several ones of said equalizing means connected to the transducers of said first array to form a first combined output, means for combining the outputs of the several one of said equalizing means connected to the transducers of said second array to form a second combined output, means for variously delaying one of said combined outputs with respect to the other combined output, means for comparing one of said combined outputs with the other combined output, and means for indicating the magnitude of said delay for which said comparison indicates maximum similarity between said combined outputs.

Claim 14

In combination with apparatus as defined in claim 11, means for synchronously varying the equalized path lengths of the first array, thereby to sweep a sensitivity beam of the first array through a preassigned angle, means for synchronously varying the equalized path lengths of the second array, thereby to sweep a sensitivity beam of the second array through another angle, means for varying the delay of one of the combined outputs with respect to the other combined output, and means for synchronizing said delay variation with both of said path length varying means, thereby to maintain the point of intersection of said two array beams at a preassigned relative location from said arrays.

Claim 15

Apparatus for locating a source of radiations through ambient noise of substantial strength which comprises a first plurality of transducers spaced apart by distances L1 along a first base line, a second plurality of transducers spaced apart by distances L2 along a second base line, each of said pluralities comprising an array, said arrays being spaced apart by a distance L3 along a third base line, means for continuously recording the output of each of said transducers on a recording medium, means for rapidly and repeatedly scanning each of said recording media to derive a time signal which is expanded in frequency and compressed in time as compared with that of said source, means connected to each of said transducers for equalizing the wave propagation path lengths from said source to the outputs of the individual ones of said equalizing means of each of said arrays, means for combining the outputs of the several ones of said equalizing means connected to the transducers of said first array to form a first combined output, means for combining the outputs of the several ones of said equalizing means connected to the transducers of said second array to form a second combined output, means for variously delaying one of said combined outputs with respect to the other combined output, means for comparing one of said combined outputs with the other combined output, and means for indicating the magnitude of said delay for which said comparison indicates maximum similarity between said combined outputs.

Claim 16

Apparatus for locating a source of radiations through ambient noise of substantial strength which comprises a first plurality of transducers spaced apart by distances L1 along a first base line, a second plurality of transducers spaced apart by distances L2 along a second base line, each of said pluralities comprising an array, said arrays being spaced apart by a distance L3 along a third base line, means for continuously recording the output of each of said transducers on a recording medium, means for rapidly and repeatedly scanning each of said recording media to derive a time signal which is expanded in frequency and compressed in time as compared with that of said source, means connected to each of said transducers for equalizing the wave propagation path lengths from said source to the outputs of the individual ones of said equalizing means of each of said arrays, means for combining the outputs of the several ones of said equalizing means connected to the transducers of said first array to form a first combined output, means for combining the outputs of the several ones of said equalizing means connected to the transducers of said second array to form a second combined output, means for variously delaying one of said combined outputs with respect to the other combined output, means for comparing one of said combined outputs with the other combined output, and means for indicating the magnitude of said delay for which said comparison indicates maximum similarity between said combined outputs.

Claim 17

In combination with two time signal sources, apparatus for rapidly determining the degree of similarity of the signals of said sources which comprises means for storing the output of each of said sources for a preassigned interval on a recording medium, means for rapidly and repeatedly scanning each of said recording media to derive time signals each of which contains the same information as one of said original time signals but on a telescoped time scale, means for variously delaying one of said derived time signals relatively to the other, means for comparing said derived time signals for various values of said delay, means for deriving from said comparing means a measure of the similarity of said time signals, whereby said measure reaches an extreme value when said original time signals coincide in phase, and means for indIcating the magnitude of said relative delay for which said measure attains said extreme value.

Claim 18

In combination with two time signal sources, apparatus for rapidly determining the degree of similarity of the signals of said sources which comprises means for storing the output of each of said sources for a preassigned interval on a recording medium, means for rapidly and repeatedly scanning each of said recording media to derive time signals each of which contains the same information as one of said original time signals but on a telescoped time scale, means for variously delaying one of said derived time signals relatively to the other, means for comparing said derived time signals for various values of said delay, means for deriving from said comparing means a measure of the similarity of said time signals, whereby said measure reaches an extreme value when said original time signals coincide in phase, and means for indIcating the magnitude of said relative delay for which said measure attains said extreme value.

Claim 19

Apparatus as defined in claim 14 wherein said comparing means comprises means for multiplying said time signals together to form a product and means for integrating said product over a time substantially equal to the time for a single traversal of one of said recording media by one of said rapid scanning means.