Abstract: A ratio analyzer employing two time-base generators which are used to convert time intervals to analog voltages. The outputs of the two time-base generators are sampled and the amplitude of one pulse is divided into the amplitude of the second pulse which gives an output voltage representation of the ratio of the two original pulse widths. The output voltage representation is indicative of the type of input signal present and thus may be used to analyze the input signal.

Abstract: In a side looking radar, electronic timing circuits for dividing the radar beam into a plurality of groups of azimuth cells of equal size, the switching circuits being dependent upon the number of pulse repetition intervals per unit of travel to maintain the size of the azimuth cells in the different groups relatively constant. The apparatus also contains circuitry for scaling the output in each of the different azimuth groups.

Abstract: A scan oscillator and a Pulse Repetition Frequency (PRF) oscillator with associated analog and digital circuits provide drive signals for two different RF PIN diode attenuators. When driven by a portable Gunn Diode Oscillator or other microwave source RF is generated that provides main lobe and adjustable side lobe radar signals to a directional microwave antenna. This output signal has adjustable scan rate, beam width, PRF, pulse width, and side lobe level and is self-contained in a package measuring 83/8.times.73/8.times.3 inches. The system allows "on the sail" testing for periscope mounted Direction Finding Systems.

Abstract: Audio frequency Doppler signals output from a radar are encoded and presented to left and right speakers of a headset. The Doppler signals are encoded so that the auditory effect produced by sounds emanating from the left and right speakers are perceived by an operator as originating from a particular location in space. In a preferred embodiment in-phase and quadrature Doppler signal outputs from a coherent radar couple through an optional phase shift to the left and right speakers. Sounds having phase differences dependent upon whether a target is approaching or receding result. The operator hears these sounds and perceives the sounds as being located toward the left or right.

Abstract: An automatic range finder and remote controlled braking system is provided. When mounted to a vehicle, this system senses the distance between the equipped vehicle and any other vehicle or object in front of it and sets off a warning alarm when the separating distance is less than some preset value. As the distance continues to close, when the distance closes to some preset braking distance, a braking alarm is activated, and controlled breaking, proportional to the rate of change of distance with respect to time commences. The actual distance is always displayed. Additional braking is accomplished by applying increased breaking force to the conventional brake pedal while a panic button can be used to disable the automatic braking entirely. The beamwidth of the corner reflector type antenna is controlled for calibration purposes by adjusting the lateral placement of the radiating dipole using a motor and worm drive system.

Abstract: Signals to control the signal processor in the linearizer of a frequency modulated continuous wave radar transmitter are generated by sampling the signal being transmitted, modulating and delaying this signal, mixing the modulated delayed signal with a second sample of the signal being transmitted to obtain an intermediate frequency signal, filtering the intermediate frequency signal to isolate the upper and lower sidebands of this signal and mixing the two sidebands to obtain a control signal having a frequency that varies directly with the beat frequency between the sampled and delayed signals.

Abstract: An adaptive learning controller (ALC) for use with an inertial navigation system (INS). To correct quadratic position errors which result from acceleration bias errors, the ALC produces a position correction signal. The position correction signal is generated by twice integrating an acceleration correction signal produced by the ALC. The ALC receives signals which indicate a current system state based on the corrected position signal and the velocity bias signal. The ALC also receives a failure signal determined by comparing the corrected position signal to predetermined failure criteria, these criteria relating to excursions of the corrected position signals beyond acceptable error limits.

Abstract: A radar apparatus for detecting a distance from a radar antenna (13) to a buried object (1) underground.The radar apparatus calculates the distance based on Maxwell's equation relating to speed of propagation of electromagnetic waves using received signals of two or more different frequencies in the receiver (5) which were transmitted from the antenna (13), and thereafter reflected from the buried object (1).

Abstract: A vehicle speedometer is disclosed which accurately measures vehicle velocity despite significant vehicle vibration, which causes variation of the angle of incidence of the measuring wave. Two transceivers are mounted on the vehicle, along with means to determine a frequency difference and an angle variation, both being used in an accurate velocity determination.

Abstract: Antenna and processing provisions for the suppression of mutual interference between flying bodies used for jamming radio/radar transmitting and receiving systems. A transmitting and receiving device is contained within the flying body for generating jamming signals in dependence of received signals. A transmitting and receiving antenna arrangement is installed on the flying body and connected to the transmitting and receiving device for producing a plurality of directional and linearly polarized electromagnetic radiation patterns covering respective azimuthal sectors, the patterns each having a major beam direction and a polarization plane which has a 45.degree. inclination with respect to a horizontal reference plane when the flying body is in the normal flight attitude, the inclination with respect to the horizontal plane being in the same direction for all of the patterns with respect to the respective major beam direction as viewed from said flying body.

Abstract: A secondary surveillance radar system in which monopulse processing is used to obtain angle estimation of azimuth bearing, involving a monopulse processor, two independent phase detectors in respective A and B channels, the arrangement being such that a log amplifier is provided in each of the respective channels and the outputs of these log amplifiers are coupled to the independent phase detectors, whereby a resultant signal is obtained giving target deviation from boresight in either direction based on differences in phase between signals appearing in the respective channels.

Abstract: A method and apparatus for detecting a short pulse signal in the presence of an interfering jamming signal wherein the jamming signal is utilized as the local oscillator in a diode mixer when it is received at a sufficiently high level for efficiently mixing with a short pulse signal. When the received jamming level is insufficient to act as a local oscillator, an internal local oscillator signal is coupled to the diode to maintain an efficient mixing operation.

Abstract: A radar system for tracking airborne targets, in which the transmitted pulse signal is swept over a predetermined frequency range (3). A local oscillator (15) in the receiver is swept over a similar frequency range the L.O. sweep modulation being initiated (20) by the first significant target return signal. Reflectors on the target at different ranges therefore produce different I.F.s in the receiver. Discrimination between the various target reflector features is thus achieved by filtering (25, 27, 29) the I.F. signals in a series of small bands, each band corresponding to a particular target-feature range. Azimuth, elevation and magnitude of a target feature can thus be obtained for each range cell.

Abstract: A short pulse radar receiver having a detector with a threshold automatically adjustable with the level of noise and interfering signals. Interfering signals at signal levels which exceed the maximum for which a threshold may be achieved to prevent a false alarm are attenuated prior to coupling to the variable threshold detector by an attenuator variable automatically in accordance with the received signal level.

Abstract: A sonar or radar permits primary distributed scatterers that are close to the sonar or radar relative to the array dimension to be rapidly and accurately located and pertinent characteristics to be estimated, such as Doppler and complex scattering strength. The region viewed is partitioned in annuli instead of in angular pie shaped slices as is normally the case for conventional sonar. This avoids the difficulty with conventional sonar or radar of distinguishing whether a scatterer is in a side lobe or the main beam an dis preferable to conventional sonars or radars in the important case of approaching multiple scatterers, e.g. robotic vehicle sensors or torpedo terminal homing on a target, because near regions may be examined in all directions prior to further regions. Computational speed is achieved by utilizing precomputation and leaving only part of the computation to be performed in real time.

Abstract: Clutter suppressors and methods of clutter suppression for radars which employ the doppler effect for enhancing signals due to moving targets relative to signals due to clutter caused by land, sea or rain. Specifically, the disclosure concerns suppressors and methods of clutter suppression for cw doppler, pulse doppler and MTI (moving target indication) radars. The suppressors reduce the occurrence of radar output due to clutter by permitting and prohibiting radar output on the basis of the strength of signals that contain doppler frequency components of the radar echo.

Abstract: A device for imparting a selected delay to a pulse emanating from a transmitter before the pulse is returned as a simulated radar echo to a radar altimeter receiver. The selected delay is obtained by recirculating the transmitted pulse through a fixed delay element a prescribed number of times. The system includes a control circuit, including a single-pole, double-throw electronic switch coupled to a presettable counter which may be preloaded with a count value corresponding to the number of iterations of the transmitted pulse through a closed loop including the delay elements. Upon each such traversal, the counter is decremented and when the counter generates a borrow signal, the electronic switch diverts the pulse to the altimeter's receiver. The recirculation loop also includes pulse amplifying and shaping circuitry for compensating for attenuation and distortion of the recirculating pulse.

Abstract: An improved display for visually presenting the reflected wave information of a sonar or radar by a plurality of displaying light-emitting elements supported on a rotating member. The display comprises a light-receiving unit formed in said rotating member on its rotating axis and including a light-receiving element for receiving an optical signal regarding said reflected wave information and sending it to said plurality of displaying light-emitting elements and a light-emitting unit having a light-emitting opening provided opposite to said light-receiving opening on a fixed member on the rotating axis of said rotating member and including a light-emitting element provided in a fixed member for sending said optical signal to said light-receiving element.

Abstract: A radar responder for transmitting an electric wave signal which sweeps a predetermined frequency deviation width including the reception frequencies of the searcher's radar a plurality of times, responding to the pulse-modulated radar signal from the searcher's radar. The responder is provided with a high frequency FM modulator having said frequency deviation width, generates a radar responding signal which repeats said sweeps a predetermined number of times with a predetermined period, and a distinction signal for distinguishing individual radar responder which repeats said sweeps with said period in a predetermined pattern.

Abstract: A "Spacercore" design is used to provide the cores of the electromagnets which are used to bias ferrite slabs in phase shifters of a high power RF attenuator. The phase shifters require a given flux to provide a phase shift from zero to 90.degree.. With laminations of high permeability silicon steel, the core weight may be substantially reduced by including a filler comprising spacers of non-magnetic material (such as lightweight transformer pressboard. With 14-mil silicon steel laminations and 64-mil spacers, this construction provides a core which weighs 25 percent of a full ferrite core for the same flux density.