Scanning arrangement for sonar beams

Claim 2

In an underwater sound detecting system of the type wherein m vertically spaced, directional beams are scanned to detect wave fronts arriving at a receiving site at different arrival angles, the combination of a multiplicity of equally spaced transducers, said transducers being arranged in a vertical line at said receiving site; a similar multiplicity of delay lines, one end of each delay line being connected to a corresponding transducer whereby the signals produced by said transducers are sent down different delay lines, said delay lines being of progressively shorter length with the delay line having the longest length being connected to the transducer at the top of said vertical line; means for extracting said signals at various points along said delay lines so as to impart to said transducers a beam pattern which includes m equally spaced, vertical beams with said signals corresponding to the acoustic signals picked up by said m-beams; and means for switching portions of each delay line into and out of its delay lines thereby to shift said directional beams by incremental amounts.

Claim 3

In an arrangement as defined in claim 1 wherein a binary counter controls said switching operation and the effective length of the portions switched into said delay line may be represented by a binary count.

Claim 4

In an arrangement as defined in claim 1 wherein the delay line portions switched into and out of the delay lines change the effective length of the delay lines by linear amounts corresponding to increasing binary counts.

Claim 5

In an underwater sound detecting system of the type wherein m vertically spaced, directional beams are scanned to detect wave fronts arriving at a receiving site at different arrival angles, the combination of a multiplicity of transducers, said transducers being arranged in a vertical line At said receiving site; a similar multiplicity of delay lines, one end of each delay line being connected to a corresponding transducer whereby the signal produced by each transducer is sent down a different delay line, said delay lines being of progressively shorter length, with the longest delay line being connected to the transducer at the top of said vertical line, each delay line including a first section which is at that end of the line that is connected to a transducer, each first section being of progressively longer length with the shortest first section being in that delay line which is connected to the transducer at the top of said vertical line, the remaining portion of each delay line being divided into m equal subsections with the subsection next to each first section being further subdivided into a multiplicity of fractional lengths; means for extracting the signals at the end of each of the equal length subsections thereby to obtain m output signals; and means for switching said fractional length sections into and out of their delay lines thereby to shift said vertically spaced, directional beams by finite amounts.

Claim 6

In an underwater sound detecting system of the type wherein m vertically spaced, directional beams are scanned to detect wave fronts arriving at a receiving site at different arrival angles, the combination of a multiplicity of transducers, said transducers being arranged in a vertical line At said receiving site; a similar multiplicity of delay lines, one end of each delay line being connected to a corresponding transducer whereby the signal produced by each transducer is sent down a different delay line, said delay lines being of progressively shorter length, with the longest delay line being connected to the transducer at the top of said vertical line, each delay line including a first section which is at that end of the line that is connected to a transducer, each first section being of progressively longer length with the shortest first section being in that delay line which is connected to the transducer at the top of said vertical line, the remaining portion of each delay line being divided into m equal subsections with the subsection next to each first section being further subdivided into a multiplicity of fractional lengths; means for extracting the signals at the end of each of the equal length subsections thereby to obtain m output signals; and means for switching said fractional length sections into and out of their delay lines thereby to shift said vertically spaced, directional beams by finite amounts.

Claim 7

In an arrangement as defined in claim 4 wherein said fractional length sections are one-eighths, two-eighths and four-eighths the length of each of said equal length sections.

Claim 8

In an arrangement as defined in claim 5 wherein the four-eighth fractional length is adjacent said first section; said two-eighth fractional length is adjacent said four-eighth length; and said one-eighth fractional length is adjacent said two-eighth length.

Claim 9

In an arrangement as defined in claim 4 wherein said means for switching said fractional lengths into and out of their delay lines includes a multiplicity of switching means, the number of switching means corresponding to the number of fractional lengths in each delay line.

Claim 10

In an arrangement as defined in claim 4 wherein a three-stage binary counter controls the open or closed condition of said switching means.