Digital depth sounder

Claim 2

In an acoustic, marine depth-sounder having means for transmitting an acoustic signal downwardly through the water when the vessel is afloat in response to an applied electrical signal, means for receiving acoustic echo signal returns propagated through the water for producing electrical signals in response thereto, and means coupling said transmitting and receiving means for producing a signal indicative of the depth as a function of elapsed time between transmitted anD received signals, wherein the improvement comprises: means for varying the amplitude of transmitted signals; means for varying the gain of said receiving means; and means responsive to said echo signal returns for controlling said transmitted signal amplitude and said receiving means gain thereby to provide said depth-sounder with maximum dynamic range to optimize the indication of the presence of true bottom signals and enable said depth sounder rapidly to provide said optimal true signals in the presence of sharply changing bottom conditions.

Claim 3

The depth-sounder of claim 1, wherein: said transmitted and received signals are pulses.

Claim 4

The depth-sounder of claim 2, wherein: means are included for displaying said depth digitally.

Claim 5

The depth-sounder of claim 3, wherein: said sounder is adapted to provide a digital display remotely.

Claim 6

The depth-sounder of claim 4, wherein: said sounder is adapted to provide a local and remote display simultaneously.

Claim 7

The depth-sounder of claim 2, wherein: said transmitting means includes a pulse generator and means for measuring the time duration between each transmitted pulse and its corresponding echo return pulse.

Claim 8

The depth-sounder of claim 6, wherein: means are included for displaying said depth digitally.

Claim 9

The depth-sounder of claim 7, wherein: means are included for detecting the average level of received echo pulses.

Claim 10

The depth-sounder of claim 7, wherein: means for rapidly determining within a few pulses the amplitude of return echo pulses.

Claim 11

The depth-sounder of claim 7, wherein: said pulse generated includes a unijunction transistor.

Claim 12

The depth-sounder of claim 6, wherein: means are included selectedly to control said receiving gain relative to said amplitude of transmitted pulses.

Claim 13

In a digital depth-sounder having means for periodically transmitting an acoustic signal pulse below the water line of a vessel, said means including an electro-acoustic transducer, to communicate acoustically with sonic reflectors below the vessel, means for receiving acoustic echo signal return pulses propagated through the water for producing electrical signal pulses in response thereto, and means coupling said transmitting and receiving means for producing a signal indicative of the depth as a function of elapsed time between corresponding transmitted and received signal pulses, wherein the improvement comprises: Adjustable amplitude transmitting means for periodically applying pulses of electrical energy to said transmitting means to transmit a corresponding pulse of sonic energy downwardly from said vessel; variable receiving means responsive to electrical signals produced by said transducer in response to the first sonic pulse received by said transducer following each transmitted pulse to produce an echo signal having a level dependent on the amplitude of said transmitted pulse and the amplitude of the echo signal pulse received; and means responsive to the level of said echo signals for simultaneously adjusting the amplitude of said transmitted pulse and the gain of said receiving means to tend to maintain the average level of the echo signals within presently determined bounds.

Claim 14

In a digital depth-sounder having means for periodically transmitting an acoustic signal pulse below the water line of a vessel, said means including an electro-acoustic transducer, to communicate acoustically with sonic reflectors below the vessel, means for receiving acoustic echo signal return pulses propagated through the water for producing electrical signal pulses in response thereto, and means coupling said transmitting and receiving means for producing a signal indicative of the depth as a function of elapsed time between corresponding transmitted and received signal pulses, wherein the improvement comprises: Adjustable amplitude transmitting means for periodically applying pulses of electrical energy to said transmitting means to transmit a corresponding pulse of sonic energy downwardly from said vessel; variable receiving means responsive to electrical signals produced by said transducer in response to the first sonic pulse received by said transducer following each transmitted pulse to produce an echo signal having a level dependent on the amplitude of said transmitted pulse and the amplitude of the echo signal pulse received; and means responsive to the level of said echo signals for simultaneously adjusting the amplitude of said transmitted pulse and the gain of said receiving means to tend to maintain the average level of the echo signals within presently determined bounds.

Claim 15

The apparatus of claim 12, further comprising: pulse generating means enabled in the interval between each transmitted pulse and the first following echo signal for producing counting signals at a predetermined rate, means for registering said counting signals, means controlled by said transmitting means for resetting said registering means when each transmitted pulse is produced, and display means responsive to each echo signal for displaying the contents of said registering means in preselected digital units.

Claim 16

The apparatus of claim 13, further comprising: means controlled by said registering means and said receiving means for producing an alarm signal when an echo signal is produced and the number of regIstered counting signals is below a predetermined value.

Claim 17

The apparatus of claim 14, further comprising: means responsive to a second echo signal produced following a transmitted pulse and preceding the next transmitted pulse, and means for producing an alarm signal when such a second echo signal is detected.

Claim 18

In an acoustic, distance measuring device having means for transmitting an acoustic signal to a target in response to an applied electrical signal, means for receiving acoustic echo signal returns propagated from said target for producing electrical signals in response thereto, and means coupling said transmitting and receiving means for producing a signal indicative of the target distance as a function of elapsed time between transmitted and received signals, wherein the improvement comprises: means for varying the amplitude of transmitted signals; means for varying the gain of said receiving means; and means responsive to said echo signal returns for controlling said transmitted signal amplitude and said receiving means gain thereby to provide said device with maximum dynamic range to optimize the indication of the presence of true target signals and enable said device rapidly to provide said optimal true signals in the presence of sharply changing target conditions.

Claim 19

In an acoustic, distance measuring device having means for transmitting an acoustic signal to a target in response to an applied electrical signal, means for receiving acoustic echo signal returns propagated from said target for producing electrical signals in response thereto, and means coupling said transmitting and receiving means for producing a signal indicative of the target distance as a function of elapsed time between transmitted and received signals, wherein the improvement comprises: means for varying the amplitude of transmitted signals; means for varying the gain of said receiving means; and means responsive to said echo signal returns for controlling said transmitted signal amplitude and said receiving means gain thereby to provide said device with maximum dynamic range to optimize the indication of the presence of true target signals and enable said device rapidly to provide said optimal true signals in the presence of sharply changing target conditions.