Abstract: A Process and device of location and destruction of an anatomic target includes the periodic emission of a focused treatment beam of elastic waves and an echographic image of the target formed in real time during the treatment period by means of an ultrasonic auxiliary beam carrying out a scanning substantially centered in a symmetry plane of the focused treatment beam. Also displayed superimposed on the target image is a mark showing the theoretical position of the focal point of the treatment beam. Selection of the image forming echoes reflected from the target as a function of the coordinates of the region of impact of the auxiliary beam with respect to the echographic source is effected and the treatment and auxiliary sources are simultaneously displaced under the control of signals derived from the selected echoes until the coincidence between the image of the mark and the image of the target object is reached where the treatment beam emission is then triggered.

Abstract: A method and apparatus for detecting objects around a vehicle, comprising a plurality of microwave-transceiver sensors for transmitting microwave signals to reflect off objects around the vehicle. The reflected signals are received and passed to a control unit for comparing the received signal to a transmitted signal to determine whether a detected object constitutes a threat to the moving vehicle. An alarm means is connected to the control unit and activates upon the receipt of an alarm signal when the control unit determines a detected object constitutes a threat to the vehicle.

Abstract: Apparatus for controlling the cutting depth of a road grooving machine by vertical adjustment of both the front and rear travelling gear on the basis of a cutting depth control signal, which is generated by a tracer ski by sampling a reference plane, including at least three ultrasonic sensors arranged one behind the other in the direction of movement of the cutter, and an evaluation means for determining the distances between the ultrasonic sensors and a reference plane to derive therefrom an inclination signal as well as an averaged distance signal. The evaluation means controls the height of the two travelling gears such that the average distance of the cutter drum as well as the position of the machine relative to the reference plane are adjusted.

Abstract: A device for mounting an ultrasonic transducer on user equipment for operation in a contaminating, ambient environment. A housing has a forwardly extending, profiled inner surface for promoting focusing along an axis of ultrasonic waves emitted by a transducer mounted against a shoulder of the casing. A chamber adjacent to a backside of the transducer is formed by a rearwardly extending portion of the casing and a cap forming an overlap portion therewith. A bladder disposed in the chamber has a port which vents into the overlap portion such that pressure equalization across the transducer is dynamically maintained. A calibrator offset by known displacement from the transducer provides a reflected wave portion to the transducer such that errors caused by temperature dependency of the velocity of propagation of the ultrasonic waves through the ambient environment can be substantially eliminated.

Abstract: A proximity device for use in determining a distance and an angular displacement between the proximity device and an object or nearest surface of an object whereby alignment can be implemented. The proximity device contains a transmitter section for transmitting signal energy, an energy source for outputting the signal energy, a dual-channel receiver section, a plurality of energy sensors for receiving signal energy reflected from an object or nearest surface of an object and a channel-control section. Within the dual-channel receiver section there are means for determining the relative distance and an angular displacement to the object or surface of the object from the reflected signal energy.

Abstract: An ultrasonic sensor control unit for a road finishing machine for generating a height control signal for a vertically adjustable beam, the ultrasonic sensor control unit including at least three ultrasonic sensors which are arranged at a considerable distance from the beam in the direction of motion of the road finishing machine. The ultrasonic sensor signals determine the distances between each ultrasonic sensor and a reference surface, the values which lie more than a predetermined distance outside of a plane which is determined by the measuring points associated with the other distances being rejected as faulty measurement. On the basis of the height signals, the mutual distances of the sensors, and the distance between a sensor and the rear edge of the beam, the evaluation means calculates the projected height at the rear edge of the beam. This height is compared with a selectable desired thickness value.

Abstract: A Doppler-effect vehicle ground-speed detecting apparatus having a transmitter fixed to a vehicle body and transmitting a wave toward a road surface on which the vehicle is running, a receiver fixed to the body and receiving a portion of the wave reflected by the road surface, and a ground-speed determining device for determining a ground-speed of the vehicle relative to the road surface, on the basis of a transmitting frequency of the wave as transmitted by the transmitter and a receiving frequency of the wave as received by the receiver. The ground-speed determining device determines the ground-speed of the vehicle, on the basis of a parameter which changes with an angle of the vehicle body relative to the road surface in a plane parallel to a running direction of the vehicle and perpendicular to the road surface, as well as on the basis of a difference between the transmitting and receiving frequencies.

Abstract: The inspection head component of a manipulator employed in the inspection of the interior surface of a nuclear reactor vessel is aligned to an optimum orientation when positioned at a local surface to be inspected. This alignment is carried out by generating ranging information with respect to the local surface using ranging ultrasonic transducers positioned upon the inspection head. The propagation interval of the acoustic signal emitted by these ranging transducers is timed and quantified to develop orientation error signals. Such development is carried out in conjunction with known values for the local surface being inspected and in conjunction with a sequence of data collection at the position. The inspection head is pivotally mounted upon the manipulator so as to be movable about at least two axes by inspection head positioning assemblies which may be provided, for example, as stepper-motors and associated translational movement components.

Abstract: A passage is periodically scanned by a plurality of ultrasonic transmitters/receivers (sensors) arranged on the ceiling of the passage in two lines to calculate the height of an object to be measured to each sensor and the presence or absence of the measured object(s), moving direction(s) thereof, and the number thereof are reckoned from changes in sensed height and sensing time for each sensor induced by passing an object to be measured through the passage, and the position and a change in position with time of each sensor which senses the measured object concerned to count the number of passers-by in each moving direction. The presence or absence of the object to be measured and the number to be counted are decided in accordance with changes in sensed position and sensed height and the interrelation thereof, so that the number of sensors can be reduced and the number of passers-by can be counted at a high accuracy even when a plurality of persons pass under the sensors in a group.

Abstract: A sonar detector system for exiting passengers on public conveyances such as buses and trolleys which detects the presence of passengers at unattended exits and opens the exit doors is disclosed. The system employs two sonar transducers/receivers at each door of the exit with narrow, electronically truncated detection zones. The sensors are positioned so as to prevent operation of the doors due to echoes from passengers on the aisle floor of the public conveyance or receipt of echoes from outside the conveyance when the doors are open. It also will not operate the doors when echoes are received from packages or debris in the stairwells of the exits. Special circuitry is used to prevent a sensor from detecting echoes from the transmission of the other sensors at the door or in the conveyance and the system is designed so that the presence of persons who are very close to the senor, i.e. within the dead space of the sonar sensor, can be detected using a single sensor.

Abstract: An acoustic sensor functioning as a digital logic device comprises a resonant chamber, at least one port establishing a first resonant frequency therein when the port is closed and establishing a second resonant frequency therein when the port is open, a transmitter in communication with the chamber and tuned to either of the first or second resonant frequencies and a receiver in communication with the chamber for providing a digital logic output. When the port is closed or open and when the transmitter is tuned to the second or first resonant frequencies, respectively, the device functions as an inverter.

Abstract: Apparatus for making a selection from between a plurality of different options such as different products vended from a vending machine including a housing structure having an elongated passageway therein, a wall at one end of the passageway, a device for introducing an acoustic pulse in the passageway at the one end and sensors means at the one end for responding to pulses introduced into the passageway and reflected back along the passageway, and a plurality of spaced selection members mounted on the housing each having a wall portion movable between positions extending into the passageway thereat and position not extending into the passageway. The invention may also be used in association with a microprocessor capable of determining the round trip travel time of a pulse introduced into the passageway including the round trip travel time when the pulse is reflected by a fixed opposite end of the passageway for calibration purposes.

Abstract: A monitoring apparatus is described for the contact-free monitoring of a region adjacent to a service robot of a ring spinning machine. The apparatus includes an electro-acoustic converter for transmitting a sonic signal which is divided into a sonic measurement signal S.sub.SM and a sonic reference signal S.sub.SR. An electronic control unit delivers a fault signal if no sonic signal has been received by the expiry of a reference transit time. If, on the other hand, a sonic measurement signal is received prior to the expiry of the reference transit time, the control unit delivers a recognition signal to indicate the presence of an object in the monitored region.

Abstract: In an acoustic pulse-echo ranging system, the transmitter and receiver, which respectively generate pulses of acoustic energy and receive reflections of the same, are electronically tuned to determine their operating frequency, the electronic tuning being controlled responsive to stored data relating to a particular transducer being utilized to transmit and receive a pulse. A single transmitter and receiver can be utilized to service a number of different transducers, being automatically tuned to an appropriate frequency for each transducer as it is used to transmit and receive a pulse. The system can verify the nominal operating frequency of each transducer, and can also adjust the operating frequency used with any particular transducer to optimize its performance.

Abstract: An acoustic device and related method for measuring the shape of an object. The device includes a plurality of transmitters for transmitting acoustic waves at an object to be measured and a plurality receivers for receiving the acoustic waves reflected by the object. A phase detector measures phase data of the reflected acoustic waves, the phase data being processed to calculate a value representing a shape of the object as a function of the phase data. This value is then compared with known reference value to accurately identify the shape of the object.

Abstract: The present invention comprises a method and apparatus for measuring the linear dimensions and determining the three-dimensional spatial volume of an object. In the preferred embodiment, all three linear dimensions are ascertained using the travel time of reflected ultrasonic waves. Measurements may be taken while the object is in motion, and the object may also be weighed.

Abstract: Automated constant depth steering and automated yaw correcting techniques for fishing boats or similar craft usable in concert or separately are disclosed. The constant depth steering arrangement controls a relative constant thrust electric trolling motor by varying the orientation of this trolling motor which propels the boat relative to the boat. The constant depth steering arrangement includes operator entry switches and potentiometers for receiving an operator selected water depth and an indication of the direction and sense in which water depth changes. The automatic yaw correcting arrangement includes a rudder-like structure for sensing the lateral component of craft motion relative to the water, and is responsive to the sensed lateral motion to imparting a lateral thrust to the craft in opposition to the sensed lateral component of craft motion.

Abstract: A height-position sensing device for use with a contol circuit for controlling the height position of a blade in the case of a motor grader includes a mechanical height-position sensor and a ultrasonic height-position sensor which are connected to a common control circuit via a switch.

Abstract: A device for determining the depth below the ground surface of a working member of an earth moving equipment, comprises a sensor for transmitting ultrasonic signal from underneath and toward the ground surface and for receiving a portion of the signal reflected from the ground surface. The sensor is positioned underneath the ground surface in fixed spatial relationship to the working member such that the sensor means is under the ground surface when at least a portion of the working member is under the ground surface. A circuit is provided for processing the received reflected signal to thereby indicate the depth under the ground surface of the working member, whereby the depth is proportional to the time of travel of the signal to the ground surface and the reflected signal to the sensor means.

Abstract: Two submerged rotatable sets of transmitting and receiving transducers are ongitudinally spaced along the side of a river to establish intersecting lateral sonar beams obliquely oriented at opposing 45.degree. angles relative to the primary river current. Each beam can be slewed in opposite directions through 45.degree. to parallel orientation with the current. The outputs of the transducer arrays are passed to respective doppler sonar detection units which produce alarm output signals when the normalized doppler frequency shift within at least one of a plurality of narrow frequency bands in each unit exceeds a predetermined level. The transmitting frequency of each array is varied with rotation of the array. If only one beam detects a target, a control circuit causes the other beam to slew until it acquires the target. With detection by both beams, the position of the target can be computed from the bearing angles of the arrays.

Abstract: A method and apparatus is provided for adjusting a preselected sweeping area width of a revolving roll-type brush rotatable around an axis for the cleaning of roadways, airport runways and the like, wherein the spacing between the axis of the revolving brush and the surface to be cleaned is altered for adjusting the sweeping surface, or area swept, and wherein, for the dimensioning of the nominal spacing, the brush diameter is detected by means of a sensor and the spacing of the brush axis from the surface to be cleaned is adjusted according to the diameter of the revolving brush. The actual spacing between the brush axis and the surface to be cleaned is measured and when there are deviations between the nominal and the actual spacing, the spacing of the brush axis and the surface to be cleaned is readjusted to the desired nominal spacing by a control circuit in order to assure that a preselected sweeping surface width or width of the area swept is maintained.

Abstract: A mine neutralization system having self-propelled explosive charges fired t submarine mines by a mine detection and fire control system.

Abstract: A detector of electrical wires which aer partially submerged in water and rtially extend out thereof having a means for broadcasting electromagnetic energy to the underwater portion thereof and means for receiving electromagnetic energy from the out of the water portion thereof.

Abstract: A control sensor for a construction machine serves for generating height control signals for the height control of a tool of the construction machine along a guide cable and contains at least two supersonic sensors, one of which at least serves as a transmitter/receiver element, whereby the supersonic sensors are connected to an evaluation means and arranged in a right angle to the construction machine's direction of movement and in such a distance to the guide cable that the detection angle of the supersonic cones will lead, at this distance, to their overlapping.

Abstract: A device for determining the depth below the ground surface of a working member of an earth moving equipment, comprises a sensor for transmitting electromagnetic signal from underneath and toward the ground surface and for receiving a portion of the signal reflected from the ground surface. The sensor is positioned underneath the ground surface in fixed spatial relationship to the working member such that the sensor means is under the ground surface when at least a portion of the working member is under the ground surface. A circuit is provided for processing the received reflected signal to thereby indicate the depth under the ground surface of the working member, whereby the depth is proportional to the time of travel of the signal to the ground surface and the reflected signal to the sensor means.

Abstract: A method of and a device for safeguarding a vehicle or machinery movable in space, such as a robot, a stacker, an operatorless transporting vehicle or the like against collision, in which by the use of distance sensors, especially ultrasonic sensors with echo time measurement, the distance from an obstacle is measured and a reaction signal is initiated when a preset threshold value is not reached, said method and device being characterized by a time-synchronous actuation of the distance sensors in a compound circuit which in case of a dangerous approach of the vehicle to an obstacle triggers a reaction signal which is either a speed reduction signal or a stop signal. Moreover, the measuring signal can be utilized as a command signal for actively influencing the vehicle movement, e.g. for driving around the obstacle or the like.

Abstract: The minehunting system includes a remotely operated vehicle which is driven ahead of a vessel. The vehicle is equipped with a sonar system for detecting, classifying and disposing of a mine.The sonar system comprises an acoustic mirror sonar which includes a dual field-of-view reflector, a height finding element and a dual frequency classifier.The vehicle has a autopilot which, is conjunction with control algorithms in a shipborne tactical computer on the vessel provides navigation and manoeuvering commands.

Abstract: This invention provides an icing preventive device for a supersonic wave transmitting and receiving unit for a vehicle which is composed of a timing device for outputting a timing signal, a supersonic wave transmitting and receiving device for transmitting a supersonic wave signal and receiving a reflected wave in response to the timing signal, a received signal processing device for amplifying the received signal caused by the reflected wave and processing the waveform of the amplified signal, a control device for controlling a vehicle load in response to the received signal of which waveform is processed, a temperature sensing device for sensing a temperature outside the vehicle, a heater operating device for energizing and heating the heater in response to both decrease in the temperature outside the vehicle and a level of the received signal of the reflected wave, and a heater arranged in the supersonic wave transmitting and receiving device, and further the present invention discloses the technology of t

Abstract: A system for the control of a member for following a moving object, especially a small object being part of larger entity, comprising an ultrasonic transmitter and receiver is characterized in that each sensor unit is fixed to the means of movement of a follower member. The ultrasonic sensor units are inexpensive and relatively insensitive to the dirt prevalent in an industrial or an agricultural environment. Since the sensor units can be brought relatively close to the object to be followed, the influence of the distracting larger entity is reduced and an accurate control system is obtained using simple reflection-sensing of the object. The control system can be applied in a milking apparatus. Furthermore the invention provides a method for the automatic milking of an animal.

Abstract: In a system for detecting the position of an object having predetermined design features in a plane relative to a manipulator provided with ultrasonic sensors consisting of ultrasonic transmitters and ultrasonic receivers, the manipulator is provided with at least three ultrasonic sensors, which are spaced apart and directed at an angle to a common reference plane, two of the sensors are directed to an elongate linear design feature of the object, the third sensor is directed to a second linear design feature of the object, the linear features are designed so that sound waves projected by the ultrasonic sensors and incident on the features will be reflected parallel to the direction of incidence, and the two linear design features are parallel to each other in a plane.

Abstract: An arrangement for controlling operation of a motor operated door is provided with doppler radar sensors facing the approach to the door from both sides. The doppler signals from the sensors are analyzed to determine the presence of motion toward or away from the door and the door is controlled to open upon motion toward the door and close upon motion away from the door.

Abstract: An ultrasonic air spring system adapted to be mounted on a vehicle for absorbing road shocks exerted on the vehicle and for maintaining the vehicle body level with respect to the axles. An air spring includes an end plate and a piston sealingly connected to the open ends of the flexible elastomeric sleeve to form a pressurized fluid chamber therebetween. A transducer is mounted on the end plate within the fluid chamber and transmits ultrasonic signals through the fluid chamber toward the piston and picks up reflected signals therefrom. A signal is generated by the transducer in response to the reflected signals and fed to a microprocessor based control module. The control module determines whether the air requires fluid feed or exhaustion and will then implement control of inlet or exhaust valves to achieve a desired axial separation between the end plate and piston.

Abstract: An ultrasonic sensor system particularly for automatic door openers of a swinging door type, in addition to sensors (14) for people approaching a door for controlling opening and closing purposes, has at least three microprocessor controlled ultrasonic beam transducer (40, 41, 42) for projecting expanded unidirectional ultrasonic beams in a selected directions in a detection zone in the path of the swinging door and ultrasonic detector for converting reflected single multiple path ultrasonic beam energy into an analog electrical signal which constitute an acoustical image of objects in and bounding the selected detection zone. This acoustical image is stored or, a number characteristic thereof is stored and this acoustic image is then compared with a later acoustical image of an object in the selected detection zone and then the comparison is used to signal a lack of correlation between the first and second acoustical images to produce a signal preventing operation of the door opening.

Abstract: The depth of water ahead of a vessel is detected by sonar means carried aboard a drone stationed by radio control ahead of the vessel. Detected depth information is transmitted from the drone to the vessel where it is displayed for use by the vessel pilot in navigating shallow waters.

Abstract: A method of and apparatus for carrying out machine vision of an object for obtaining object data therefrom in which the object is illuminated by frequency swept ultrasonic stress wave energy from a transmitting and receiving transducer array, or by light energy from a source, reflected signals are received respectively by the array and an optical-electronic camera, respective images in terms of the data contained in these received signals are fed to a processor in which the data is analysed to make use of the best data derived from both sources of illumination and the resulting data compared with reference data to provide stimuli controlling a reject device and/or positional adjustment devices directing the array and/or the camera.

Abstract: A self-guidance system for submarine vehicles containing a parametric sonar including preformed channel, transmission device and, in each channel, two beams at the primary frequencies formed simultaneously. Reception takes place with preformed beams at the primary and the secondary frequencies followed by a filter giving frequential channels. An echo comparator receives the signals at the primary and secondary frequencies and enables interference echoes from decoys in particular to be eliminated and the rudders to be controlled.

Abstract: Obstruction detector apparatus operatively coupled to an automatic electric door operator compares the time span of transmission and receipt of reflected echoes of ultrasonic energy within a door passageway obstruction zone with predetermined time spans in order to prevent door closure under conditions indicating passageway obstruction or system malfunction. Signal generators provide timing signals respectively representative of the anticipated time span of reflected echoes from locations in front of, and beyond, the door jamb opposite the ultrasonic transmitter and receiver transducers for comparison by a relay controller with the time of generation of a signal representing a reflected echo at the transducer receiver, the relay controller appropriately actuating a door operator relay in response to such comparison.

Abstract: Apparatus (and method) for parts sorting and the like wherein parts and the like are transported into an interaction region and irradiated with wave energy which interacts with the parts and the like to provide wave energy that emits from the interaction region. The positions of the parts and the like as they move through the interaction region are detected at spaced locations along the path of travel therethrough. The wave energy that emits from the interaction region is sensed to derive a characteristic of the parts and the like at each of the spaced locations to provide signals from which the characteristic can be determined. The signals are analyzed for each spaced location to derive data representative of the characteristic which serves as the basis for sorting.

Abstract: An apparatus for properly aligning a cathode-ray tube projection unit before a viewing screen includes a pair of ultrasonic rangefinders and a cooperating pair of light emitting diode (LED) reader units. One ultrasonic rangefinder and one reader unit are connected to each of two opposite sides of the projection unit. Each rangefinder is directed toward the viewing screen to sense the distance between the viewing screen and the side of the projection unit to which the rangefinder is connected. The cooperating LED reader unit then indicates whether that side is too close to, too far away from or a proper operating distance from the viewing screen.

Abstract: An obstacle detection system has a sensor unit including a plurality of ultrasonic transducers and sequentially changes the number of pulses provided to groups of transducers, thereby performing front center sensing, front right sensing and front left sensing. The time between emission of ultrasonic waves and reception of waves reflected by an obstacle is calculated by a timer. A microcomputer computes the distance data and position data of the obstacle in accordance with obtained timer data and sensing region data.

Abstract: An ultrasonic transducer assembly incorporating an ultrasonic transducer and conically surfaced beam transformer wherein the conical surface of the beam transformer is mounted on the interior of closure means or end cap that seals the transducer (and any associated mechanisms) from the environment during non-operating periods and is moved into the prescribed position via rotational motion or a linear piston-like motion prior to operating periods. Suitable O-ring or gasket sealing means preserve the water tight integrity during non-operating periods and assures a seal during translational movements of the transducer assembly from operating to non-operating positions. On school buses, the beam transformer is translated to an operative position below the bus where, in conjunction with a microprocessor, it takes an accurate acoustic image before the bus door is opened and again before the bus resumes forward motion so as to detect whether students have crawled under the bus while it was stopped.

Abstract: An obstacle sensing area ahead of a mobile robot is divided into a plurality of sensing regions. A number of ultrasonic transmitters and plural receivers on the robot cooperate to detect the presence of obstacles in the sensing regions. Coordinates representing four corners of each sensing region, and time data representing a time period from emission of ultrasonic waves from selected transmitters to reception of the waves by each receiver when the waves are reflected by an obstacle at each corner point, are prestored in data ROMs. The data ROMs are retrieved by a CPU in response to obtained time data, and precise position data of the obstacle in the sensing area is determined.

Abstract: A method for evaluating echo signals transmitted and received by an ultrasonic transducer in a sensor of a movable mechanical element, such as an arm of an industrial robot, has the steps of receiving and storing the arriving echo signals in chronological sequence in a memory, the chronological sequence of the signal being converted into a corresponding sequence of memory positions, with successive sequences of echo signals of successive transmit pulses being stored in the same sequences of the memory positions. Integration of the echo signals of the successive sequences stored in the memory positions are undertaken such that the local shift of the ultrasonic transducer disposed on the moveable element which occurs between respective transmit pulses is compensated relative to chronologically adjacent pulses and the pulses reflected from a target are more easily identified.

Abstract: The device comprises at least two ultrasonic transducers emitting focused radiation and a circuit making it possible to measure the difference between the sampled signals supplied by these two transducers. This difference is cancelled out when the probe faces the object.Application to metrology and the position control of objects.

Abstract: A sonar ranging/light detection system provides information regarding the surrounding environment to a robot. The sonar portion of the system includes an upper rotating detector which provides 360.degree. coverage as well as a lower, fixed detector located on the front of the robot which provides sensory information in the direction of robot movement. A light detector similarly provides a 360.degree. light sensing capability. The upper sonar and light detectors utilize a common rotating mirror driven by a stepper motor and include a slotted shaft encoder in combination with an optopair semiconductor detector. The shaft encoder provides angular information to a microcomputer controller which is also responsive to sonar ranging information in exercising control of the stepper motor. The transmitted sonar signal is comprised of a pulse train of four different frequencies to ensure that simultaneous echoes from more than one surface do not cancel each other out and provide false ranging information.

Abstract: A system for sorting parts wherein a part to be sorted is irradiated with wave energy of a single frequency (or very narrow band of frequencies) which interacts with the part. Wave energy emanating from the part is sensed at many spatially separated places to generate an electric signal representative of a characteristic of the amplitude and phase of the detected wave energy at each place. The electric signal so generated is compared with a pre-established signal and any differences therebetween are determined to establish whether the part is within acceptable limits in terms of geometric characteristics, e.g., size, material characteristics and orientation. The part is then acted upon on the basis of the comparison.

Abstract: A system to measure geometric and electromagnetic characteristics of objects. Wave energy of a single frequency (or very narrow band of frequencies) is directed upon an object which reflects (or otherwise interacts with) the wave energy. The reflected wave energy is sensed by many spatially spaced sensors to provide electric signals whose amplitude and phase components are combined to give a quantity from which geometric and/or electromagnetic characteristics of the object can be ascertained.

Abstract: An improved method and apparatus for optimally focusing an image at a focal plane of a plurality of subjects located at substantially different distances from an image-forming adjustable focus lens system of the type that is responsive to a rangefinder derived signal, where the rangefinder is one that normally generates a subject distance signal representative of the distance to the nearest of a plurality of different distance subjects. Improved focusing is achieved by generating a composite signal representative of the relative size of each of the plurality of subjects and their distance from the rangefinder and then comparing this composite signal with that of the above-mentioned nearest subject distance signal. A signal representative of the degree of deviation of these signals from one another is then employed to optimally focus an image of the plurality of different distance subjects at the lens system focal plane.

Abstract: An ultrasonic system is responsive to the relative position of a movable device within a fluid-filled structure. A transducer transmits ultrasonic signals from a location fixed within the structure to the device for reflection thereby and for picking up the reflected signals.

Abstract: The detection and localization of an antiship torpedo is accomplished by ustic and optical means. A ship's sonar determines the approximate location of the incoming torpedo and a laser scans this location with energy in the blue-green spectrum. Surface reflections are gated out of a linear detector array and reflected portions of the scanning beam which penetrate the water's surface are divided among the elements of the linear detector array into field of view element signals. These field of view element signals are subsequently compared in time and amplitude to determined disparities between them which point to the torpedo's position, depth and bearing. Optionally, spectral and polarizing filters are provided to enhance the signal to noise ratios and to facilitate signal processing.