Abstract: Synthetic discriminant function automatic target recognition system augmented by LADAR combines, through the synthetic discriminant function (SDF), the active LADAR data of the potential target object with the passive infrared imagery of the target and background. In doing so, the system not only recognizes and classifies the target but also provides the range profile of the target object by analyzing the amplitude of the reflected return signal when appropriate. The live target scene imagery in passive infrared is detected, filtered and subsequently complex multiplied with pre-existing synthetic discriminant function to produce a two-dimensional cross-correlated surface. Analogous process is performed on the active LADAR range and intensity images of the live target scene with corresponding pre-existing synthetic discriminant function for the same target pose and scale as in the passive infrared correlation step.

Abstract: Interferoceivers are apparatus which use optical fiber loop based radio frequency (RF) signal train generators to store transient pulses and regenerate their identical replicas for analysis. The present invention further advances the art of RF signal train generators and interferoceivers in investigating acoustical, electromagnetic, and optical transient phenomena. The disclosure includes mechanisms for tuning the interferoceivers, and means for forming synthetic images with chaotic pulses or pulses of opportunity.

Abstract: Apparatus for detecting the presence of a speed detection system includes a microcontroller, a laser detector circuit coupled to the microcontroller, a radar detector circuit coupled to the microcontroller and a display coupled to the microcontroller, wherein the microcontroller receives signals from the laser detector and radar detector circuits and in response to the signals fed thereto, the microcontroller provides an output signal indicating which of the laser and radar detector circuits fed a signal thereto.

Abstract: A radar system comprises an optical fiber RF storage subsystem for storing a portion of RF signals before the transmission. The radar system further comprises a coherent RF receiver to process reflected RF signals using stored RF signals as a reference. Furthermore, the optical fiber RF storage system is used to store initially received RF signals for comparison with sequentially received RF signals.

Abstract: An improved remote speed sensing technique is described which improves performance reliability by increasing the relative signal to noise ratio of a speed detector compared to that of a vehicle radar detector, by localizing at least one axis of the illuminating radiation to an angular region which is comparable to or within the subtence of the target vehicle, while minimizing illumination of a radar detector on the target vehicle.

Abstract: An apparatus and method for accurately determining a target distance in adverse weather conditions utilizing both LASER and RADAR is disclosed. The radar signals are used to determine an approximate range which is then used as a gating window for the determination of which laser reflection is from the actual target as opposed to a reflection from the atmospheric interference. The method basically comprises the steps of initiating a radar pulse in the direction of a target and receiving a reflection, transmitting a laser signal and receiving a plurality of reflections, determining an approximate range based on the radar signals, and using this approximate range to ascertain which of the laser reflections is from the target. This determination is preferably made by generating a gating signal and gate width from the radar signals and passing the set of laser range signals through the gate to eliminate the false signals and select the signal that survives the gate as the accurate target range.

Abstract: A radar/laser speed detection countermeasure device for use on a motorcycle is disclosed which detects and annunciates radar and/or laser based speed detection devices in use in the immediate physical area for the purposes of speed limit law enforcement. The device consists of a main detector body mounted in an interior cavity of a motorcycle, which is electrically connected to a remote mounted sensing head unit and a remote mounted indication and control panel. Hidden components and interconnecting wiring reduce the chance of theft and preserve the appearance of customized motorcycles.

Abstract: An optical heterodyne system provides the radiation source and beam scan control of a millimeter wave (MMW) array antenna. The heterodyne system is an optical feed system to produce the MMW by mixing the optical outputs from two lasers, distribute the signal source to an array of radiating elements through a Rotman lens and optical fibers, generate the differential phase shift for beam scan in the optical domain, change the beam direction by switching the input laser being used to illuminate the Rotman lens or by varying the frequency of one of the laser sources. The feed system includes a plurality n-1 lasers spaced along the transmit side of the lens, and a center laser disposed on the center axis of the transmit side. A l:n switch receives a command input to determine which of the n-1 lasers will operate. The beat frequency between the center laser operating frequency and that of the n-1 lasers is the MMW frequency.

Abstract: A dual-mode surveillance system with a radar and an electro-optical mode. The radar mode is afforded by a conventional manned radar surveillance station fitted with an imaging assembly. The electro-optical mode is afforded by means of at least one electro-optical surveillance station with tracking capability located remote of the manned radar surveillance station.

Abstract: In a radar target position detecting apparatus, beams (, for example, light beams) irradiated from a transmitter(, for example, LED) have a predetermined divergence angle, a plurality of light (beam) receiving elements such as photodiode arrays each having a different receiving angle (directivity) are arranged in an array form, and a direction of a reflected wave (beam) is identified according to a position of the arrayed beam (wave) receiving elements in the array at which the reflected wave (beam) is captured.

Abstract: A SAR radar has an optical processor which uses an electrical-signal-to-light modulator. The modulator includes a tapped delay line which may be either analog or digital, and the signals tapped from the delay line are applied to an array of temporary storage elements, which in the case of analog signals may be a capacitive sample-and-hold, or for digital signals may include storage registers. In order to improve the signal-to-noise ratio (SNR) by comparison with a processor using an acoustic modulator, the signals tapped from the delay line are sampled at a display sampling rate, which is very low by comparison with the signal sampling rate or the highest frequency of interest, and the sampled signals are held until the next following display rate pulse. The signals held in the temporary storage elements are applied to the modulator elements, so that the optical pattern remains fixed for relatively long periods of time during which the optical processing can integrate photons for improved SNR.

Abstract: A multistatic radar signature measurement apparatus comprising a curvilin sensor array of photonic sensors which are used to measure the radar cross section of a target. The array of photonic sensors provide for the simultaneous collection of target scattered measurement data over an approximately semi-spherical field of view. Laser light passing through each photonic sensor of the sensor array is modulated by the photonic sensor in direct proportion to the strength/intensity of scattered waves from the target as the scattered waves pass through each photonic sensor of the sensor array. The modulated light from each sensor of the sensor array is then transmitted to an optical switching network which samples the optical signals from the array. The sampled optical signals are next provided to an RF receiver which converts the sampled optical signals to equivalent RF electrical signals.

Abstract: A collision avoidance and warning system for land vehicles including radar transmission and receiving apparatus for sensing the presence of objects within a spatial range relative to a vehicle, multiple target tracking apparatus receiving an output from the radar transmission and receiving apparatus for tracking a plurality of targets sensed by the radar transmission and receiving apparatus, auxiliary non-radar target sensing apparatus and alarm decision apparatus receiving an input from the multiple target tracking apparatus and from the auxiliary non-radar target sensing apparatus for indicating the alarm status of a target and providing an output indication to alarm generating apparatus.

Abstract: A system (10) for friend-or-foe identification (IFF) comprises an interrogator unit (18) carried on a first platform (T1) for generating and transmitting a laser beam. A control unit (22) selectively directs the transmitted laser beam toward a second platform (T2). A coding/decoding unit (28) encodes an IFF interrogator message with which a portion of the transmitted laser beam is modulated. A laser reflector (30) carried on the second platform receives the coded laser beam. The reflector is a normally passive reflector which is activated by receipt of the transmitted laser beam. The reflector responds to the IFF message contained in the received laser beam by modulating the unmodulated portion of the transmitted laser beam. This newly modulated portion of the laser beam is reflected back toward the first platform. The coding/encoding unit decodes on the first platform receives and the response, and determines if it corresponds to a predetermined response which identifies the second platform as a "friend".

Abstract: A method and system are provided for marking marine channels. A single laser beam is selectively interrupted to produce an identifying on/off laser beam sequence distinguishable by the human eye. The laser beam is then expanded in terms of beam diameter during specifically timed periods of laser beam transmission. The expanded laser beam is projected along a beam path that is substantially along the center of a marine channel to be marked at a height above the water's surface. The height of the beam path is selected such that marine traffic may pass under the beam path without obstructing same.

Abstract: An underwater maneuverable vehicle is presented which carries an explosive charge and can be used for immediate removal or destruction of various menaces to navigation and other underwater hazards. The battery powered vehicle is air dropped from a platform which carries an imaging lidar system for detection and is operated and navigationally controlled in conjunction with an imaging lidar system. In accordance with an important feature of this invention, an optical lidar downlink is used to control the submerged underwater maneuverable vehicle from an airborne platform. The downlink is pulse spaced modulated. Command signals are secure, and are decoded aboard the vehicle. Control in speed, heading and depth, as well as command detonation are available using this technique.

Abstract: A distant target vibration assessment and signature determining apparatus for operation from a vibrating platform such as an aircraft or helicopter. The disclosed system employs pulse illumination of the distant target and of nearby atmospheric aerosol particles and uses the latter illumination derived signal as a characterization in reverse of the vibrations of the sensor's mounting platform. The nearby and distal nature of the two illuminated energy reflections enables their range gated segregation and individual transformation into the frequency domain. Frequency domain vibration signatures of the distant target and the vibrating platform are then individually obtained and subtracted in order to obtain a clean vibration spectrum representation of the distant target. Variations of the system including a two pulse operating cycle, the use of signal strength evaluation and signal processing alternatives are also disclosed.

Abstract: An Identification Friend or Foe (IFF) system uses CO.sub.2 laser identification beacons on ground vehicles such as tanks, in conjunction with an existing (or future) Forward Looking InfraRed (FLIR) detection system on an attacking aircraft or ground vehicle, to provide a cost effective solution to the problem of identifying friendly targets on a battlefield. The CO.sub.2 Laser can produce radiation only in the FLIR's spectral band, aiding stealth and improving signal to noise ratio. An acousto-optical modulator in conjunction with a specially shaped optical reflector steers the beam in the desired direction toward the FLIR in the attacking aircraft, aiding stealth and detection signal to noise ratio. The optical element also shapes the beam into the desired angular extent, needed for reception by the attacking aircraft.

Abstract: An active night vision system capable of viewing a target over long distances utilizes laser illumination in eye-safe, invisible wavelength regions of about 1.52-1.76 .mu.m or about 2.03 .mu.m-2.34 .mu.m for illuminating a target; and electronically receives, intensifies and displays or stores the reflected image.

Abstract: A camera system in which microwave radiation from objects in a field-of-view is collected by an antenna having beam directions which are a function of the beam frequency. The collected radiation is used to modulate an optical beam to impose upon the beam spectral components which are functions of the frequencies of the microwave radiation. The modulated beam is then analyzed by an optical spectrum analyzer to produce an image of objects in the field of view. In a simple embodiment of the invention a one dimensional image is produced. This one dimensional image can be converted to a two dimensional image by panning the camera system or mounting the camera on a moving platform. In this preferred embodiment the spectrum analyzer comprises an angle-frequency filter (preferably an etalon). The portion of the modulated beam passing through the etalon is directed in a number of directions, the directions being a function of the spectral components of the modulated beam.

Abstract: A lidar apparatus for detecting an object. The lidar apparatus includes a laser providing a visible light output signal over a first field of view and a photodiode having a second field of view. At least some of the first and second fields of view overlap. The photodiode provides electrical signals in response to received optical signals. A controller is coupled to the laser and to the photodiode. The controller for provides electrical signals to the laser, causing emission of visible light output signals. A time varying threshold generator is coupled to the controller. The time varying threshold generator provides a time varying threshold signal in response to signals from the controller. A threshold detector is coupled to the time varying threshold generator and to the photodiode. The threshold detector compares the time varying threshold signal to the electrical signals to provide signals indicating presence or absence of the object.

Abstract: A bistatic radar system includes a transmitting radar site; a receiving radar site; and an optical fiber RF link system for transmitting RF signals from the receiving site to the transmitting site and for transmitting command and control signals from the transmitting site to the receiving site.

Abstract: An optical RF stereo systems includes multiple remote vehicles, a processing center, and optical RF link systems for transmitting RF signals from remote vehicles to the processing center and for transmitting command and control signals from the processing center to remote vehicles.

Abstract: A collision-avoidance method for cooperating carriers consists of:transmitting, from each carrier, monochromatic pulsed light waves, coming from at least two wide-field optical transmission devices to cover the space around the carrier and thus define a zone of proximity, the power of the optical transmission defining, under given weather conditions, the range of the transmission and hence the zone covered;and receiving, at each carrier, the monochromatic, pulsed light waves radiated into space by other cooperating carriers, on at least two wide-field reception devices covering the space around the carrier. Each intrusion of a carrier into the proximity zone of another carrier prompts the detection of light radiation and the triggering of an alarm on either carrier. Applications are to air anti-collision systems.

Abstract: A method and apparatus for aiding a landing aircraft. Three differently-colored beams of laser light are produced and transmitted, one of the beams of laser light being transmitted in a plane containing the direction from which the aircraft is approaching. Another of the beams of light is transmitted on one side of the plane, and the third of the beams of light is transmit on the other side of the plane. The pilot of the aircraft can determine whether the aircraft is on the plane or to the one side or the other by the color of the light the pilot receives. If desired, at least one of the colored laser beams that is transmitted toward one side of the plane can be broken into a plurality of adjacent fan-shaped beams, the light in at least one of the fan-shaped beams being interrupted intermittently.

Abstract: A laser warning receiver (LWR) having an ability to not only detect a low power level laser source, such as a pulse train emitted by a laser beam rider, but to also provide a high angular resolution in determining the angle of arrival of that pulse train. The receiver includes a lens/filter arrangement for a large area photodetector to detect an incoming signal from an emitting source and a high gain amplifier to amplify the signal which is then applied to a synchronization generator that generates a digital pulse train with pulses corresponding to peaks in the incoming signal. The digital pulse train is applied to a code breaker where the code is analyzed and a further code is generated anticipating the arrival of further pulses in order to verify the code. That further code is applied to a time gate generator which generate a code, synchronized with the incoming signal, that controls the high voltage of a gated image intensifier which is coupled to a video camera.

Abstract: An identification friend-or-foe system for vehicles wherein each vehicle is provided with a radiation transmitter and a receiver with a detector for detecting radiation transmitted by other vehicles. Each transmitter can transmit a first coded signal which can be detected by the receivers in other vehicles, the receivers providing an unblocking signal after the first coded signal is correctly identified. The unblocking signal clears a radiation transmission path in the vehicle, the path containing a reflector which reflects the received signal back to the source of the transmission. The reflector adds a further predetermined code to the signal reflected from the reflector with each vehicle having another detector for detecting a reflected signal and a device to identify the further predetermined code.

Abstract: A laser-radar type distance measuring equipment for a motor vehicle is shown, which comprises a probe unit including a laser emitting device and a reflected laser receiving device. The probe unit is mounted on the vehicle body. A steering angle sensor is used for producing an information signal representative of the steered angle of the vehicle. A so-called performance changing device is employed for changing the performance of the probe unit. A control unit controls the performance changing device in accordance with the information signal issued from the steering angle sensor.

Abstract: A radar test system for producing multiple delayed replicas of a radio frequency radar signal is provided. A laser diode is adapted to receive the radar signal and generate a modulated optical wave signal carrying the radar signal. The modulated optical wave signal passes through a fiber optic delay line. The delayed optical wave signal engages a partially transmissive and reflective assembly wherein a first portion of the optical wave signal is transmitted therethrough and a second portion is reflected back to the laser diode. That portion of the optical wave signal reflected back to the laser diode is amplified therein and subsequently regenerated. The signal transmitted through the partially transmissive and reflective assembly is demodulated to extract the optical wave leaving only the radar signal. In this manner, a series of multiple echoes of the radar signal is produced.

Abstract: A vehicular optical radar apparatus comprising a light emitting portion for irradiating a signal light on an object ahead and a light receiving portion for receiving a reflected light from the object. At least one of a light emitting lens and a light receiving lens are deformation-worked so that a distance between optical centers of the light emitting and receiving portions can be moved closer together, and an angle formed between an incident axis of incoming light and so that an outgoing light becomes small.

Abstract: An underwater maneuverable vehicle is presented which carries an explosive charge and can be used for immediate removal or destruction of various menaces to navigation and other underwater hazards. The battery powered vehicle is air dropped from a platform which carries an imaging lidar system for detection and is operated and navigationally controlled in conjunction with an imaging lidar system.

Abstract: An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering is disclosed. The transmitter of the micro pulse lidar is a diode pumped .mu.J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited by optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that micro pulse lidar systems are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere.

Abstract: An underwater maneuverable vehicle is presented which carries an explosive charge and can be used for immediate removal or destruction of various menaces to navigation and other underwater hazards. The battery powered vehicle is air dropped from a platform which carries an imaging lidar system for detection and is operated and navigationally controlled in conjunction with an imaging lidar system. In accordance with an important feature of this invention, an optical lidar downlink is used to control the submerged underwater maneuverable vehicle from an airborne platform. The downlink is pulse spaced modulated. Command signals are secure, and are decoded aboard the vehicle. Control in speed, heading and depth, as well as command detonation are available using this technique.

Abstract: A coherent laser radar system operating at an eyesafe wavelength above 1.4 microns has been provided for measurement of the position and velocity of hard targets and aerosol targets, said system comprising a frequency-stable master laser and an injection-seeded Q-switched slave laser for generating signals for transmission to the target. Means for obtaining highly accurate velocity and range measurements are provided. Data from signal transmissions and receptions taken over a range of angles are analyzed to map target positions and velocities in time and space.

Abstract: A differential amplifier for gigahertz bandwidth electrical signals using fiber optics and integrated optical devices has a differential gain which is a function of the electrical to optical and optical to electrical conversion factors. The common mode rejection ratio of the differential amplifier at 1 GHz was greater than 30 dB and the common mode rejection ratio depended on the time difference between the differential amplifier inputs. A differential amplifier fabricated in accordance with this inventive concept could be used as an integrated module in radar and communications systems.

Abstract: A target detecting and range determining system for an automobile detects a distance between two vehicles travelling in front of and behind each other and includes a range detector using a range determining signal directed toward and reflected by a target vehicle. The system also includes a controller for controlling the range detector so that it receives a proper reflection of the range determining signal when a primary vehicle changes its travelling direction relative to the target vehicle.

Abstract: A parallel to serial converter converts parallel detected signals output m a linear array of photodetector cells to an uncorrected serial signal. A comparator compares the uncorrected serial signal from the parallel to serial converter with a previous offset stored in a shift register. An offset difference output from the comparator is added to a previous offset output from the shift register to provide a new offset for input to the shift register. An operate adder finally provides a corrected serial signal by adding the uncorrected serial signal from the parallel to serial converter and the new offset output from the learn adder.

Abstract: Radiant energy intermittently emitted from a transmitter is reflected as o pulses from a moving target being interrogated to produce Doppler signals by counting of photons of the echo pulses during time domain intervals between emission from the transmitter. Such counting of photons is limited to the time domain intervals by operational control of a laser pump through which a reference beam is generated at an energy level activating detectors irradiated by such beam to count the photons absorbed therein after capture of the photons by a receiving antenna.

Abstract: An identification of friend from foe (IFF) device is described containing a radio transceiver (F) which, in addition to being designed for communication purposes, is equipped for transmitting, receiving, and evaluating IFF signals. The IFF device further includes a laser transmitter (LS) and an optical receiver (LE) which are coupled to the radio transceiver (F) via a controller (G). For identification, unmodulated direction-selective light signals and modulated nondirectional radio signals are used.

Abstract: A laser beam is frequency shifted for use in a laser radar ranging system driving a single optical modulator with multiple drivers to produce several frequency shifted drive frequencies. The shifted beam is transmitted to and from a target via an afocal lens. The return reflected beam, which includes phase shifted information is mixed in a detector with the local oscillator frequency to remove the local oscillator frequency. The electrical output from the detector is filtered by bandpass filters and phase detected in a signal processor to obtain range information.

Abstract: An IFF system comprises an interrogation device having an antenna arrangement operating in the HF or microwave range with a relatively broad radiation characteristic for radiation of coded interrogation pulses and for receiving answer signals. The IFF system cooperates with a position finding device whose transmission pulses are radiated by way of a relatively narrow radiation lobe and wherein the answer signals are triggered in the answering device in response to the arrival of transmission pulses of the position finding device.

Abstract: Pulses of short duration are radiated by an impulse radar transmitter wit time domain intervals under control of a clock to monitor a moving target from which echo pulses are reflected. The echo pulses received are measured by a quantum detector in terms of photon energy levels to supply signal data processed during periods between said time domain intervals.

Abstract: A pulse radar for operation at 94 GHz and higher frequencies is shown to include an antenna, a diplexer and first detector that are each optically fed so that radio frequency signals may be, when transmitting, passed through the diplexer to the antenna and, when receiving, from the antenna through the diplexer to the first detector.

Abstract: A surveying instrument for satellite position-measuring includes, a range finder (2), which is preferably non-contact-measuring and tiltable, combined with a satellite receiver (1) in a geometrically unambiguously defined relative position. These two instrument parts are mounted geometrically unambiguously in common plumb rod (3) or on a measurement stand. A vertical sensor (4) and a sighting device (5) are additionally provided, whereby simultaneous monitoring and setting respectively of the vertical direction and of the direction of the range finder measurement beam is permitted. Using the instrument, it is also possible to determine, in terms of coordinates, such points which formerly could not be surveyed using satellite position-measuring systems.

Abstract: A transmit/receive circuit for each of the antenna elements of a radar phased array including an optical fiber true time delay circuit responsive to an electrical RF signal for providing an optical signal having a controlled time delay, an optical fiber for propagating the time delay controlled optical signal, an optical detector circuit responsive to the propagated time delay controlled optical signal for providing a time delay controlled electrical signal, transmit circuitry responsive to the time delay controlled electrical signal for providing to the associated antenna element a transmit signal based on the time delay controlled electrical signal, and receive circuitry responsive to the time delay controlled electrical signal and the signal received by the associated antenna element.

Abstract: A target detector (1) for detecting targets provided with transmitter means (3, 5) for simultaneous generation of different electromagnetic waves having different frequencies which are transmitted by means of an emission and detection device (2). The target detector is also provided with receiving means (3, 4, 5) for obtaining, by means of the emission and detection device (2), target signals comprising target information received at different frequencies. A signal processing unit (15, 16, 17) is provided for processing the target signals in combination to obtain target-representing signals.

Abstract: An electro-optical spin measurement system for a spin model in a spin tunnel includes a radio controlled receiver/transmitter, targets located on the spin model, optical receivers mounted around the perimeter of the spin tunnel and the base of the spin tunnel for receiving data from the targets, and a control system for accumulating data from the radio controlled receiver and receivers. Six targets are employed. The spin model includes a fuselage, wings, nose and tail. Two targets are located under the fuselage of the spin model at the nose tip and tail, two targets are located on the side of the fuselage at the nose tip and tail, and a target is located under each wing tip. The targets under the fuselage at the nose tip and tail measure spin rate of the spin model, targets on the side of the fuselage at the nose tip and tail measure angle of attack of the spin model, and the targets under the wing tips measure roll angle of the spin model. Optical receivers are mounted at 90.degree.

Abstract: A wideband, true time delay antenna beamforming network 10 for millimeter wave phased array antennas is disclosed herein. The beamforming network 10 of the present invention includes a laser 30 for generating a beam B of electromagnetic energy. The beamforming network 10 further includes an electro-optic modulator 40 for modulating the beam B in response to an input signal S modulated about a first frequency f.sub.o. A first antenna array 80 generates a first electromagnetic field pattern P by radiating the modulated beam B' in a first direction. The present invention further includes a constrained lens 90 for receiving the first field pattern P and for emitting an antenna driver feed beam F in a second direction in response thereto. An antenna array driver 115 electro-magnetically coupled to the constrained lens 90 by the feed beam F provides a set of signals modulated about the first frequency f.sub.o to drive an antenna array 20.

Abstract: An image of a target (11) is produced by illumination of the target (11) with overlapping fields (18, 20) of wave energy, such as coherent light, producing an interference pattern (22) moving across the target. At least one pair (12) of sources (14, 16) wave energy provide the moving interference pattern (22). The scattered illumination reflected from the target is detected by a non-imaging receiver (24); a two dimensional spatial frequency map is recorded (30, 62), based upon the amplitude, frequency and phase of the illumination received; and a two dimensional image of the target is formed (32, 72) by applying a Fourier transform to the two dimensional frequency map.

Abstract: An optical RF stereo systems includes multiple remote vehicles, a processing center, and optical RF link systems for transmitting RF signals from remote vehicles to the processing center and for transmitting command and control signals from the processing center to remote vehicles.