Towed array condition appraisal system

Claim 2

Apparatus for determining selected parameters related to the operation of an acoustic array which contains a number of interconnected sensor elements, said apparatus comprising: means for projecting test signals of selected acoustic frequencies; cart means for successively bringing said projecting means into selected, closely spaced relationship with each of said sensor elements included in a length of said array, said cart means comprising a supporting frame to which said projecting means is fixably joined, and roller means for enabling said array to be moved along its centerline in relation to said cart means and said projecting means; means for controlling the operation of said cart means; and means coupled to said sensor elements for monitoring the response of a given one of said sensor elements to said test signals when said projecting means and said given sensor element are in said closely spaced relationship.

Claim 3

The apparatus of claim 1 wherein said array comprises a linear array of sensor elements which is deployable in a liquid medium, and wherein: said projecting means comprises means for projecting acoustic test signals so that the response to said test signals of a particular one of said sensor elements is discretely detectable when said particular sensor element and said projecting means are in said closely spaced relationship.

Claim 4

The apparatus of claim 2 wherein said projecting means comprises: a selected number of acoustic signal projection elements; and means joined to said supporting frame for maintaining said acoustic projection elements in an annular array, the inner dimensions of said annular array being selected in relation to the largest cross-sectional area of said linear array so that said length of said linear array is enabled to freely pass through said annular array.

Claim 5

The apparatus of claim 3 wherein: said roller means comprises a selected number of pairs of rollers, the rollers of a given pair being positionable so that they are in opposing relationship and in contact with the outer surface of said linear array; and said cart means includes a securing means for cooperating with said roller means to maintain said projecting means and said array in closely spaced, substantially coaxial relationship.

Claim 6

The apparatus of claim 4 wherein said linear array is deployed in an ocean environment, one end of said linear array comprising a forward end and the other end of said linear array comprising an after end, said forward end receiving a towing force, and wherein said controlling means includes: means for retaining said cart means and said projecting means at said forward end of said linear array until a selected time, and for enabling said cart means and said projecting means to traverse said linear array after said selected time; and drogue means joined to said cart means for retarding motion of said cart means in order to cause said cart means and said projecting means to traverse said linear array from said forward end to said after end after said selected time.

Claim 7

The apparatus of claim 5 wherein said controlling means includes: a timing means for generating an activation signal at a preselected time; means for securing said cart means and said projecting means to said forward end until said preselected time; means responsive to said activation signal for releasing said cart means and said projecting means from said forward end when said activation signal is generated; means for resisting rotational motion of said cart means in relation to said array when said cart means and projecting means are secured to said forward end; and means joined to said after end of said linear array for retaining said cart means and said projecting means at said after end after said cart means and said projecting means have traversed said linear array.

Claim 8

The apparatus of claim 6 wherein: a battery is joined to said cart means for providing power for said projecting means and for said timing means; and buoyancy means is joined to said carrier means for effecting neutral buoyancy in said ocean environment to an assembly which includes said cart means, said projecting means, and said battery.

Claim 9

The apparatus of claim 6 wherein said means for resisting rotational motion comprises: a flat thin tethering member which is fixably joined to said forward end of said linear array in perpendicular relationship; and first and second flat prongs fixably joined to an end of said carrier means in spaced apart relationship, the spacing between said prongs being selected in relationship to the thickness of said tethering member to enable said tethering member to be received between said first and second prong members when said carrier means is secured to said forward end of said array.

Claim 10

The apparatus of claim 8 wherein: said securing means includes a wire of selected strength, one end of said wire being joined to said tethering member, and the other end of said wire being joined to said carrier means; and said releasing means comprises means joined to said wire and responsive to said activation signal for cutting said wire at said preselected time.

Claim 11

The apparatus of claim 5 wherein said controlling means includes: means for selectively securing said cart means and said projecting means to said foward end of said array; means for projecting an acoustic activating signal into said environment at arbitrarily selected times; means joined to said cart means for receiving said acoustic activation signal, and for generating a cart release signal in response to said acoustic activation signal; and means responsive to said cart release signal for releasing said cart from said forward end of said array.

Claim 12

The apparatus of claim 3 wherein said cart means comprises: first and second frame components; a selected number of first rollers, each of said first rollers being rotatably joined to said first frame component by means of a first roller support, each of said first roller supports being fixably joined to said first frame component; a number of second rollers equal to said number of first rollers, each of said second rollers being rotatably joined to said second frame component by means of a second roller support, each of said second roller supports being pivotably joined to said second frame component; and resilient means for joining said first frame component and said second component so that each of said first rollers and each of said second rollers is in contact with the outer surface of said linear array, each of said first rollers being included in a set with one of said second rollers, the first and second rollers of a set being maintained in opposing relationship, said resilient means and said pivotal second roller supports cooperating to vary the spacing between the first and second rollers of a set to enable unimpeded relative motion between said cart means and said linear array as the cross sectional area of said array varies along the length of said array.

Claim 13

The apparatus of claim 11 wherein: each of said first rollers and each of said second rollers is formed of rigid material, and has an hour glass-shaped cross section for maintaining said annular projection array and said linear array in said coaxial relationship.

Claim 14

The apparatus of claim 4 wherein said pairs of rollers comprise: first pairs of rollers rotatably joined to said supporting frame for constraining movement of said linear array in a first degree of freedom; and second pairs of rollers rotatably joined to said supporting frame for constraining movement of said array in a second degree of freedom which is orthogonal to said first degree of freedom.

Claim 15

The apparatus of claim 13 wherein: each of said rollers of said first and second pairs is formed of compliant material for conforming to the cross section of said linear array to maintain said annular projection array and said linear array in said coaxial relationship.

Claim 16

The apparatus of claim 2 wherein each of said sensor elements comprises a discrete hydrophone, and wherein said monitoring means comprises: signal processing means receiving the responses of said hydrophones to said acoustic test signals; and strip chart recording means for indicating the response of each of said discrete hydrophones to said test signals.

Claim 17

The apparatus of claim 2 wherein each of said sensor elements comprises a discrete hydrophone, and wherein: said monitoring means comprises means for monitoring the individual response of each of said hydrophones to a continuous signal included in a selected acoustic frequency range.

Claim 18

The apparatus of claim 2 wherein each of said sensor elements comprises a discrete hydrophone, and wherein: said apparatus includes means joined to said projecting means for varying the frequency of said projecting means to project signals indicating the depth of said cart means in said environment; and said monitoring means comprises means for recording the position of said cart means along said linear array at which a given one of said depth indicating signals is projected.

Claim 19

The apparatus of claim 2 wherein each of said sensor elements comprises a discrete hydrophone, and wherein: said apparatus includes means joined to said projecting means for varying the frequency of said projecting means to project signals indicating the magnetic heading of said cart means in said environment; and said monitoring means comprises means for recording the position of said cart means along said linear array at which a given one of said bearing indicating signals is projected.

Claim 22

The method of claim 19 wherein: said retaining step comprises the step of retaining a plurality of discrete acoustic projectors at said forward end of said linear array; said releasing step comprises the step of releasing said projectors from said forward end at different arbitrarily selected times by generating acoustic command signals; said step of operating said acoustic projecting means comprises the step of projecting test signals such that the response of said given sensor element to said test signals is discretely recordable; and said method includes the step of preventing said projecting means from falling off the after end of said array and being lost.

Claim 23

The apparatus of claim 19 wherein: said step of operating said acoustic projecting means comprises the step of projecting test signals of an acoustic frequency which represents the depth of said projecting means in said environment.

Claim 24

Method of claim 19 wherein: said step of operating said acoustic projecting means comprises the step of projecting test signals having a frequency which represents the heading of said projecting means in said environment at a given time.

Claim 25

The method of claim 19 wherein: said step of operating said acoustic projected means comprises the step of projecting test signals of an acoustic frequency which is selected so that the sensitivity of each of said sensor elements may be determined.