Abstract: A system (400) for positioning and navigating an autonomous vehicle (310) allows the vehicle (310) to travel between locations. Position information (432) is derived from global positioning system satellites (200, 202, 204, and 206) or other sources (624) when the satellites (200, 202, 204, and 206) are not in the view of the vehicle (310). Navigation of the vehicle (310) is obtained using the position information (432), route information (414), obstacle detection and avoidance data (416), and on board vehicle data (908 and 910).

Abstract: An automatic noise threshold circuit and method automatically sets an operating threshold for a signal receiving section of a laser pulse transmitting device such that a constant noise pulse firing rate is output from a detector to provide maximum return signal sensitivity and enable detection of the weakest possible laser pulse in order to obtain maximum performance out of a laser range finder. The circuit sets the noise pulse rate at that point at which, in conjunction with a firmware based process, the actual return signals from the target can be discrimintated from the accompanying noise.

Abstract: The present invention provides an object reflector detection system, in which laser beam is emitted toward an object reflector and reflection light beam is received to detect presence or absence and position of the object reflector, whereby there are provided a laser beam emitter and a reflection light beam detector, and further a laser beam emitter for emitting polarized irradiation light beam toward the object reflector, and a reflection light beam detector for detecting polarized reflection light beam from the object reflector, and the reflection light beam detector having a first detection means for detecting polarized reflection light beam from the object reflector, a second detection means for detecting polarized light beam different from the polarized reflection light beam from the object reflector and a reflection light beam detection circuit for identifying the object reflector based on comparison between output of the first detection means and output of the second detection means.

Abstract: New apparatus comprise a optical fiber based RF signal train generator for storing transient RF pulses and regenerating the identical replicas for analysis. The apparatus further comprise RF receivers to process one stored pulse with a reference to other stored pulse. The present invention drastically increases our abilities to investigate acoustical, electromagnetic, and optical transient phenomena.

Abstract: The invention aims to increase an expansion angle in a road surface direction in a short-distance area without setting a detection range one-sidedly and without sacrificing a maximum detection distance.A double-focus lens is integrally formed by disposing a short-focus portion in the vicinity of a center and a long-focus portion on the periphery of the short-focus portion. A light source is disposed at a distance slightly shorter than the focal length of the short-focus portion of the double-focus lens. When light is emitted from the light source to the double-focus lens, light emerging from the short-focus portion has a small expansion angle such as not to diffuse largely. Therefore, the emerging light can be caused to reach a long distance. On the other hand, light emerging from the long-focus portion has a large expansion angle such as to diffuse to some extent.

Abstract: An apparatus for guiding the traveling of a moving body along a predetermined traveling path with a high degree of accuracy by accurately and reliably determining a corrected position and a corrected traveling direction of the moving body. A moving distance of the moving body between points of reception of light beams is obtained by a counter, and a CPU calculates a corrected position of the moving body by using an angle formed by the projecting directions of the light beams, the position of installation of a reflecting mirror, and an estimated traveling direction obtained on the basis of an output of a rate gyro. A corrected traveling direction is then calculated by using the corrected position thus calculated. The corrected position is calculated by using the traveling direction thus estimatively calculated.

Abstract: A system is described for rapidly and accurately determining the topography of land masses as well as individual x,y,z coordinates of discrete targets. The system incorporates a laser altimeter, a laser scanning/steering system with sensor for receiving reflected laser beams, a global positioning system or other non-ground-based reference means, a video camera, computers, and processing software. The system, mounted to an aircraft, selectively scans or steers a pulsed laser altimeter over a swath or point on earth. A Global Positioning System (GPS) or other non-ground-based reference means records the aircraft's position, altitude, and time of position. Concurrently, a computer system records and time tags the laser's range, scanner angles, and airborne platform's roll, pitch, and heading. The processing software correlates all events and measurements using time to determine precise x,y,z coordinates of the ground/targets.

Abstract: A laser range finder that is modular so that it can mounted on different weapon platforms. A pulsed infrared laser beam is reflected off the target. The timed return signal is then used to measure the distance. Another laser, either a visible laser or another infrared laser of differing frequency, is used to place a spot on the intended target. Notch pass optical filters serve to eliminate ambient light interference from the second laser. The range finder using projectile information stored in the unit processes the calculated distance to raise or lower the finder on the weapon. A plurality of weapon platforms and projectile is selected by pressing the desired rubberized keypad. The range finder can-be used with a laser detonated projectile that can be detonated when the projectile is over the target. The projectile is fitted with a detector that is sensitive to the frequency of a wide angle laser beam that is attached to the weapon.

Abstract: A distance measuring apparatus comprises projection means, light receiving means, computation means and scanning means. The projection means projects plural laser beams in different directions. The light receiving means receives the light reflected from each of objects in respective beam directions. The computation means computes the distances to the objects on the basis of the reflected light. And the scanning means sequentially changes the projecting directions of said plural laser beams.

Abstract: A system including a laser survey instrument for determining positional data of a selected target. The laser survey instrument generates optical pulses which are transmitted to and reflected from the selected target back to the survey instrument. The survey instrument determines the range to the selected target responsive to the transmission and reflection of the optical pulses. The survey instrument also determines horizontal and vertical angles between the survey instrument and the selected target. Values of the range and the horizontal and vertical angles form positional data. Once determined, the positional data is modulated upon the optical pulses to form an optical signal which is transmitted to a remote site.

Abstract: In a light-wave distance meter, a light source device emits reference modulated light beams from multiple spatially-separated light emitting areas, an optical means radiates a light beam derived from the multiple modulated light beams to the target of measurement, a light beam reception means receives the reflected return light beam from the target and converts it into an electrical pulse signal, and a distance measuring means calculates the distance to the target based on the time difference between the light beam emission and the return light beam reception. The low coherence and high intensity light beam produced by the light source device enables the extension of the maximum measurable distance.

Abstract: A picture detecting sensor unit has a passive sensor resolving a field of view into picture elements having different brightness. Picture processing means receive data from the picture detecting sensor. An additional active LADAR sensor having a laser emitting a laser beam and a scanning system for scanning an area of the field of view by this laser beam provides distance signals from the radiation reflected by an object in the field of view. The scanning of the field of view by the LADAR sensor is controlled by the picture processing means associated with the passive sensor such that the scanning effected by the LADAR sensor is limited to objects detected by the passive sensor in the field of view. A common imaging optical system is provided for the LADAR sensor and the passive sensor. A beam splitter separates the beams detected by the passive sensor and the returning beams of the LADAR sensor.

Abstract: Disclosed is a distance measuring equipment comprising: a light emitting element for generating a pulse beam; and a light receiving element for receiving a reflected pulse beam from an object under measurement with respect to the pulse beam generated from the light emitting element and converting the reflected pulse beam into an electric light receiving signal.

Abstract: An active imaging system for viewing targets with a high degree of range resolution of approximately one foot. The imaging system utilizes a laser pulse which passes through an electro-optical pulse slicer which creates a sharp leading edge and/or a sharp falling edge on the laser pulse. The laser pulse travels to the target under observation, illuminates and reflects off of the target and returns to a camera. A target is viewed only during the time all or a portion of the returning laser pulse overlaps the time the camera shutter gate is open. The imaging system is particularly suited for determining depth information about a target by varying the time relationship when the returning laser pulse is received by the camera.

Abstract: A safety distance measuring device employing an electromagnetic wave is provided. A laser diode 2 is energized to emit laser beams by a laser diode drive circuit 3 in accordance with a clock signal generated by a control circuit 29. The emitted laser beams are sequentially changed to predetermined scanning directions by a scanner 1 associated with control circuit 29. The scanned laser beams from scanner 1 are reflected by an object 19 to be received by a photodiode 5. An output of the photodiode is applied to control circuit 29 through a light receiving circuit 6 where an elapsed time from emission to receipt is computed to obtain a distance from scanner 1 to object 19. Based on data relating to scanning directions by a scanning position detector 4, a begin-and-end detecting circuit 28 can stop the radiation of electromagnetic waves around a scanning start point and a scanning end point which is danger to human bodies.

Abstract: In a laser radar system, in which pulses from a laser are focused by a telescope onto a target, the back-scattered radiation being deflected by polarizing beam splitter onto a detector in conjunction with a reference beam, the reference beam being produced from pulses derived from the pulse laser by the beam splitter, the pulses making repeated journeys around a cavity and a proportion of the pulse being emitted each time so that each input pulse produces a multiplicity of output pulses to form the reference beam, thereby avoiding the need for a separate laser for the reference beam.

Abstract: Disclosed is a distance measuring apparatus having a clock generating element, a light emitting element, a light receiving element, a sample pulse generating element, a sample hold element and a processing element. The clock generating element generates a clock pulse at a predetermined time interval. The light emitting element generates a pulse beam in synchronism with the clock pulse. The light receiving element receives a reflected pulse beam from an object and converts it into an electric signal. The sample pulse generating element generates a sample pulse at a timing delayed by a predetermined minute time from a generating time of the clock pulse within one measuring period. The sample hold element effects sampling of an output signal from the light receiving element with the sample pulse. The processing element calculates a distance to the object by detecting it from the output signal of the sample hold element and from the delay time of the sample pulse.

Abstract: A distance measuring device of laser beam using type has a laser diode for producing laser beams. A scanning mechanism projects the laser beams against an object and includes a polygon mirror to and by which the laser beams are directed and reflected. A receiver mechanism receives the laser beams reflected by the object. A control unit measures the period required for the laser beams to make the trip around the object. The polygon mirror is so arranged as to be rotated about a first axis and swung about a second axis.

Abstract: An optical distance measurement apparatus for measuring the distance to an object 7 on the basis of the round-trip time of the light to and from the object. 7 includes an object detector means 32 and a smear detector means 33. The smear detector means 33 detects a smear when the ratio of unsuccessful measurements (i.e., the measurements by which no object is detected) is greater than or equal to a predetermined level. Alternatively, the number of successive measurements of a distance less than a predetermined threshold level (e.g., 50 meters) is stored in a counter, and the smear is detected when the content of the counter becomes greater than or equal to a predetermined number.

Abstract: An interferometric switch for spatially switching either linearly polarized or unpolarized externally derived beams of substantially coherent light includes an optical input unit for dividing an externally derived light beam into a constituent beam pair. An optical phase modulating device includes a nematic liquid crystal pixel for selectively shifting the relative phase of the constituent beam pair. An output unit cooperates to combine respective components of the constituent beam pair along coincident collinear paths so as to form a respective output light beam directed along a selected one of first and second output axes, according to the relative phase imparted by the phase-modulating device. The phase modulating device may comprise a cascading arrangement of pixel stages which can respectively provide a selected incremental phase-shift to each constituent beam passing therethrough.

Abstract: A large area movement robot including a chassis, controllable apparatus for displacement of the chassis, navigation apparatus for controlling the operation of the controllable apparatus, the navigation apparatus comprising a scanning range finder mounted on the chassis, apparatus associated with the scanning range finder for determining the azimuthal orientation of a retroreflecting object whose range is simultaneously determined by the scanning range finder and apparatus responsive to the sensed range and angular orientation of the retroreflecting object for providing operating instructions to the controllable apparatus.

Abstract: A system for sensing objects in the flight path of an aircraft and alerting the pilot to their presence includes a laser radar subsystem for emitting a beam of laser energy, receiving returns from objects, and processing the returns to produce range data related to the range of the objects from the aircraft. A scanning subsystem scans the beam and produces directional information related to the instantaneous direction of the beam relative to the aircraft. Processor circuitry controls operation, processes the range data and directional information with instrumentation data from the avionics system, produces video information related to the range, direction, and type of the objects, and interfaces the video information to the video display system.

Abstract: A laser radar has a pulsed laser (11) which controllably transmits light pulses (12) into a measurement region (13), a photoreceiver arrangement (22) which receives the light pulses (12') reflected back by an object (14) located in the measurement region (13), and an evaluation circuit which, taking account of the speed of light, determines a distance signal characteristic for the spacing of the object (14) from the time between the transmission and reception of a light pulse. Between the measurement region (13) and the pulsed laser (11) there is arranged a light deflecting device (15) which deflects the sequential light pulses at increasingly changing angles into the measurement region and simultaneously transmits to the evaluation circuit an angular position signal representative for its instantaneous angular position. The evaluation circuit derives the location of the object within the measurement region from the spacing signal and the angular position signal.

Abstract: An ultrasonic ranging device and method for positioning a working implement relative to a datum is disclosed. The ultrasonic ranging device is coupled to the implement and is capable of transmitting an ultrasonic ranging pulse toward the datum and further capable of detecting the occurrence of an echo of the ranging pulse. The ultrasonic ranging device periodically makes a ranging measurement by transmitting an ultrasonic pulse toward the datum and then detecting the occurrence of any echo within a time interval, and repeats this ranging step at a predetermined repetition rate. The ultrasonic ranging device also detects any spurious echoes by detecting the occurrence of an echo within the time interval following no transmission of an ultrasonic pulse. If a spurious echo is detected, then the predetermined repetition rate is changed so that the spurious echo will not interfere with a ranging interval.

Abstract: A system is provided that corrects the undesirable fast power modulation observed at an output of a wideband frequency modulated (FM) laser. The correction is accomplished by applying a corrective voltage to an amplitude modulated (AM) modulator. The response of the laser is first measured to characterize the laser. Iterative predictions of appropriate voltage correction waveform, based upon the observed power modulation and the laser's response are then applied to the AM modulator to reduce the unwanted laser power modulation.

Abstract: A method and apparatus for a fiber optic measuring system is disclosed which works on the speed of propagation principle. The device can be utilized to determine the position of a disturbance or electronic source along the length of an optical path.

Abstract: A vehicle control system (12) is provided which comprises a range measurement system (14) which transmits a signal (20) to a target (22) and receives an echo signal (24) returned from the target (22). The range measurement system (14) comprises a transmitter system (26) and a receiver system (28). The receiver system (28) generates an analog signal representative of the range. The target (22) transmits the range signal to a processor (30). Processor (30) may be used to provide warning signals and to control a conventional speed control system (16) coupled to the throttle (18) of a vehicle (10).

Abstract: A laser ranging and detection system includes a laser for generating a coherent outgoing beam and a telescope. The telescope includes a primary mirror with an aperture for receiving the coherent outgoing beam and for passing an incoming, incoherent, backscattered light. A focal system is positioned between the laser and the telescope and focusses the coherent outgoing beam so as to create a reduced beam-waist cross section at a focal plane. A beam separator is positioned at the focal plane and in a first path between the focal system and the telescope. The beam separator includes a reflective surface arranged to reflect the incoherent backscattered light to a second path for detection. The beam separator further has an optical aperture positioned in the first path, that exhibits a cross sectional area approximately equal to the reduced beam-waist cross section.

Abstract: An improved system for using reflected energy signals sensed by light detecting optics to identify flat surfaces that are orthogonal to the detecting optics. A light source generates a laser light beam, the beam is scanned across a target scene, and a reflected signal is sensed by light detecting optics to produce an electrical representation of the reflected signal. The representation is stored in an array in the form of a plurality of data elements. The data elements are sequentially analyzed by comparing the range of each data element with the ranges of a selected number of neighboring elements, and giving the data element under analysis a corresponding "index." Data elements whose ranges closely match neighboring data elements are assigned higher indices. Neighboring data elements with high indices therefore signify proximate points on a flat surface, which is orthogonal to the detecting optics.

Abstract: An apparatus and method for mounting a range finding instrument to a theodolite telescope incorporates the necessary geometry to enable a linear spring assembly to be able to accurately balance the mass of the range finder and theodolite combination rotating in a vertical plane about a pivot point defining a first axis. In a particular embodiment of the mounting system, two compression springs are mounted in a single straight spring tube which is attached to the range finder but is allowed to rotate about a second axis. The resultant geometry of the arrangement provides a substantially exact balance for the weight of the range finder irrespective of the vertical angle of the theodolite telescope.

Abstract: A light wave distance measuring apparatus structured such that frequency dividing circuits create a base intermediate frequency outputted to a phase measuring circuit and a PLL reference frequency which is a multiple of an integer a (a.gtoreq.2) of the base intermediate frequency, and this PLL reference frequency is outputted to a PLL oscillation circuit, thereby preventing an error in the measurement of distance due to spurious components caused when measuring a phase in the light wave distance measurement.

Abstract: A phase compensation technique and apparatus utilizes a laser transmitter, acousto-optic/electro-optic modulators and a GRIN lens array to send out and receive phase shifted laser beams. Turbulence and optical phase distortions are compensated on outgoing and received wavefronts utilizing signal processing of the detected, mixed received and local oscillator beams.

Abstract: A light based distance, velocity and acceleration sensor which uses phase difference to determine the desired measurement. A laser signal is modulated by an oscillator signal and reflected off an object to a signal receiver. The reflected laser signal and the oscillator signal then pass through a dual path conditioning circuit, where the path lengths and circuit elements of the two paths are identical to cancel the effects of propagation delays in an output signal. The conditioned signals are passed through a phase comparator, to produce a signal indicative of the phase difference between the oscillator signal and the reflected laser signal. The phase difference is directly proportional to the distance between the sensor and the object.

Abstract: A surveyor's retro-reflective device, such as a corner cube prism, is striped along the reflective surfaces to provide an internal visual center target. The precise center of the prism is identified by the visual target which allows the prism to be used both for distance measuring purposes as well as visual alignment for the one step setting of surveying points or locations. The corner cube prism has the ridges of the intersecting reflective surfaces on the back of the prism striped or lined either with a stripe having equal thickness or tapered towards the center apex of the prism. The stripes are formed with a highly visible paint, ink, tape, or sheet material. This arrangement produces a highly visible visual center target. The prism target can be mounted in an enclosed case and the case can be rigidly mounted or tiltably mounted on a horizontal axis to tilt the prism in a vertical direction for use in mountainous terrain.

Abstract: Apparati and methods are disclosed for detecting vibrations, displacements and motions of a remote surface with high sensitivity, high frequency response and high accuracy using a laser beam with optical modulation, optical hetrodyning and phase detection. High speed digital signal processing is used. Shared aperture design is employed for utilization of a flat target, double-pass design for large lateral movement tolerance with high resolution, and dual target design for detection of displacement as well as angular changes in vibrational motion.