The processing of reflected signals

Claim 2

Apparatus for processing echo signals received by receiver equipment in response to a transmitted pulse, the apparatus comprising: means (30,44) responsive to the return echo signal (A) received by such equipment (S) to define a time slot (C) synchronised with a pulse of said echo signal; characterised by means (33) for utilising said time slot to extract only a portion of said pulse of the return echo signal, said time slot being such that the utilising means provides a signal representative of a characteristic of only the leading edge of said pulse.

Claim 3

Apparatus according to claim 1, wherein the utilising means (33) comprises integrating means (Rl, Cl), whereby said representative signal is representative of the.area under said leading edge of said pulse.

Claim 4

Apparatus according to claim 1 or 2, wherein the responsive means comprises level detecting means (10, 7, 14c) to define one end of said time slot in dependence upon the moment at which the level of the return echo signal passes through a preset level.

Claim 5

Apparatus according to claim 3, wherein said one end is defined by said signal level rising through the preset level.

Claim 6

Apparatus according to claim 3 or 4 wherein the other end of the time slot is defined by means responsive to a signal representative of the transmitted pulse, such that said other end occurs a given time after the occurrence of the transmitted pulse.

Claim 7

Apparatus according to claim 3 or 4 for use with a repetitive transmitted pulse and thus a repetitive return echo signal, wherein the other end of the time slot is defined by means (43) so responsive to said pulse of said echo signal that said other end of the time slot for one echo pulse occurs a given time after the occurrence of the corresponding echo pulse (El) in the preceding cycle.

Claim 8

Apparatus according to any one of the preceding claims for use with equipment (S) wherein pulses are transmitted repetitively so that cycles of return echo signals are received, wherein there are means (35, R2, C2) for holding said representative signal produced in one cycle for display in a subsequent cycle when, in that subsequent cycle, said time slot is not definable in relation to the return echo pulse owing to poor signal reception.

Claim 9

Apparatus according to claim 7, and comprising sample-and-hold means (33, 39, 35, R2, C2) provided to hold said representative signal and including switching means (35) responsive to said pulse having an amplitude below a given level to prevent updating of the output of the sample-and-hold means.

Claim 10

Apparatus according to any one of the preceding claims, for use with sea bed classifying echo sounding, wherein said response means are such as to define said time slot to extract the leading edge of the second bottom echo component.

Claim 13

A method according to Claim 10, wherein the echo signal is derived by transmitting a pulse towards the sea bed, and said identified pulse is a bottom echo pulse.

Claim 14

A method according to Claim 11, wherein a series of pulses is transmitted towards the sea bed, the identifying step identifies said bottom echo whenever it occurs in each cycle of return echoes, and the step of forming the integral includes averaging the areas under the leading edges of a plurality of successive ones of said bottom pulses.

Claim 15

Apparatus for processing the return echo signals produced as the result of transmitting a series of pulses, and comprising timing means (30, 44) responsive to an echo pulse (El) of given property within the echo signals in each cycle of return echo signals to define a time period (C) synchronised relative to said echo pulses, characterised by means (C2) for storing a characteristic of the return echo signals, means (38) for displaying the currently stored characteristic, sampling means (35) for controlling the supply of data to the storing means (C2) in dependence upon said time period (C) such that the stored characteristic is representative of that portion of the return echo signals which is within a given time slot of the cycles, and means (47,48) responsive to the absence of said echo pulse in one cycle of return echo signals for controlling the sampling means (35) to prevent sampling and thus to prevent updating of the storing means (C2).

Claim 16

Apparatus for processing the return echo signals produced as the result of transmitting a series of pulses, and comprising timing means (30, 44) responsive to an echo pulse (El) of given property within the echo signals in each cycle of return echo signals to define a time period (C) synchronised relative to said echo pulses, characterised by means (C2) for storing a characteristic of the return echo signals, means (38) for displaying the currently stored characteristic, sampling means (35) for controlling the supply of data to the storing means (C2) in dependence upon said time period (C) such that the stored characteristic is representative of that portion of the return echo signals which is within a given time slot of the cycles, and means (47,48) responsive to the absence of said echo pulse in one cycle of return echo signals for controlling the sampling means (35) to prevent sampling and thus to prevent updating of the storing means (C2).

Claim 17

Apparatus according to Claim 13, wherein there are integrating means (Rl, Cl) for integrating the return echo signals to obtain said characteristic.

Claim 18

Apparatus according to Claim 14, wherein said storage means comprises capacitance (Cl) and said sampling means comprises a controllable switch (35) for coupling the integrating (Cl) and storage means (C2).

Claim 19

Sonar or radar equipment when in combination with apparatus according to any one of claims 1 to 9 and 13 to 16.

Claim 20

Medical ultrasonic diagnostic equipment when in combination with apparatus according to any one of Claims 1 to 8 and 13 to 16.

Claim 21

Equipment comprising a transmitter (S) for transmitting a series of acoustic pulses of ultrasonic frequency in a direction with a horizontal component, and a receiver for processing return echo signals consequent upon echo of the transmitted pulses, characterised in that the receiver comprises a circuit having: means (30,32) for defining a time slot for extracting from the return echo signal that portion returning from a reflection within a selected range; and means (Rl,Cl) for averaging the extracted signal in each repetition.

Claim 22

Equipment comprising a transmitter (S) for transmitting a series of acoustic pulses of ultrasonic frequency in a direction with a horizontal component, and a receiver for processing return echo signals consequent upon echo of the transmitted pulses, characterised in that the receiver comprises a circuit having: means (30,32) for defining a time slot for extracting from the return echo signal that portion returning from a reflection within a selected range; and means (Rl,Cl) for averaging the extracted signal in each repetition.

Claim 23

Equipment according to claim 18, wherein. there are means (31) for adjusting the timing of at least one of the ends of said time slot.

Claim 24

Equipment according to claim 19, wherein the adjusting means (31) provides adjustment relative to the time of emission of the transmitted pulse (TX).

Claim 25

A circuit for use in detecting the nature of the seabed from the return echo signal of hydro-acoustic transmitter-receiver equipment (S), the circuit comprising means (30) for defining a time slot to extract from the return echo signal an echo component, characterised in that the defining means is designed to . extract the first.bottom echo component, or at least one bottom echo component other than the first, and there are means (Fig 9) for processing the extracted component to produce a width signal when the width of the extracted component exceeds an adjustable value.

Claim 26

A circuit for use in detecting the nature of the seabed from the return echo signal of hydro-acoustic transmitter-receiver equipment (S), the circuit comprising means (30) for defining a time slot to extract from the return echo signal an echo component, characterised in that the defining means is designed to . extract the first.bottom echo component, or at least one bottom echo component other than the first, and there are means (Fig 9) for processing the extracted component to produce a width signal when the width of the extracted component exceeds an adjustable value.

Claim 27

A circuit according to claim 21, wherein the defining means is responsive to the return echo signal in such a manner as to extract the second, or subsequent, bottom echo component.

Claim 28

A circuit according to claim 21 or 22, wherein the defining means is such as to mask from return echo signals all bottom echo components before and subsequent to a selected bottom echo component.

Claim 29

A circuit according to claim 21, 22 or 23, and comprising threshold means to define a signal level at which to define said width.

Claim 30

A circuit according to any one of claims 21 to 24, wherein the processing means comprises means for defining a masking signal initiated by the extracted component and means for comparing the masking signal with a delayed version of the extracted component to provide said width signal when the trailing edge of the delayed version occurs after the trailing edge of the masking signal.

Claim 31

A circuit according to claim 25, wherein the length of said masking signal is adjustable to vary the width at which said width signal occurs.

Claim 34

A circuit for use with hydro-acoustic transmitter-receiver equipment, to provide an indication of ground conditions, characterised in that the circuit comprises timing means (26) responsive to return echo signals to define a time slot embracing more than one bottom echo signal, integrating means (89) for integrating the return echo signal received within said time slot, and means for providing an indication of the integrated value.

Claim 35

A circuit for use with hydro-acoustic transmitter-receiver equipment, to provide an indication of ground conditions, characterised in that the circuit comprises timing means (26) responsive to return echo signals to define a time slot embracing more than one bottom echo signal, integrating means (89) for integrating the return echo signal received within said time slot, and means for providing an indication of the integrated value.

Claim 36

z9. A circuit according to Claim 28, wherein the timing means provides a time slot to embrace all bottom echo components.

Claim 37

A circuit according to Claim 29, wherein the timing means provides a time slot to include the second bottom echo component but not the first.

Claim 38

A circuit according to Claim 30, wherein the timing means provides a time slot (Q) to embrace all bottom components but the first.

Claim 39

A circuit for use in detecting the nature of the seabed from the return echo signal of hydro-acoustic transmitter receiver equipment, characterised in that the circuit comprises means (Fig 11) for defining a time slot (Q) to extract from the return echo signal the second, or later, bottom echo component, and means (89) for integrating the extracted component to provide an indication of its energy content.

Claim 40

A circuit for use in detecting the nature of the seabed from the return echo signal of hydro-acoustic transmitter receiver equipment, characterised in that the circuit comprises means (Fig 11) for defining a time slot (Q) to extract from the return echo signal the second, or later, bottom echo component, and means (89) for integrating the extracted component to provide an indication of its energy content.

Claim 41

Apparatus according to any one of Claims 9 and 13 to 16, or a circuit according to any one of Claims 21 to 26 and 28 to 32, wherein to define a time slot to extract the second or third bottom component, there is

Claim 42

vided a digital counter (83) to count in one direction from an initial transmission until a first bottom echo component is received and then count in the other direction substantially to define the expected time of occurrence of the second bottom echo component.

Claim 43

vided a digital counter (83) to count in one direction from an initial transmission until a first bottom echo component is received and then count in the other direction substantially to define the expected time of occurrence of the second bottom echo component.