Abstract: An angle of arrival (AoA) of an electromagnetic wave is determined. A phase of an antenna signal associated with each of two receive antenna is measured. A measured phase difference of arrival (PDoA) of the electromagnetic wave is determined based on the measured phase of each of the antenna signals. The measured PDoA is corrected based on one or more crosstalk factors associated with the two receive antennas. The AoA of the electromagnetic wave at the two receive antenna is generated based on the corrected measured PDoA.

Abstract: A radar system may include an antenna structured to transmit a radar signal and receive reflected radar signals from targets and a processor operably connected to the antenna. The radar system may receive a first reflected signal, having a first arrival angle, at a first time. The radar system may receive a second reflected signal, having a second arrival angle at a second time. The second arrival angle may be equal to the first arrival angle plus an angle offset calculated based on a velocity hypothesis. The radar system may translate the first vector by applying the angle offset, thereby calculating a translated first vector. The radar system may calculate a beamforming spectrum based on the translated first vector and the second vector. The radar system may identify peaks in the beamforming spectrum to identify angular positions of multiple targets.

Abstract: A measurement system for identifying a source direction of a wireless electromagnetic emitter signal is described. The measurement system is a radio frequency measurement system that comprises a rotary antenna and an analyzer or analysis unit being connected to the rotary antenna in a signal transmitting manner. The rotary antenna is a directional antenna and configured to receive the emitter signal and to forward the received emitter signal to the analysis unit for further processing. The measurement system is configured to gather a momentary position of the rotary antenna. The analysis unit is configured to determine a momentary frequency spectrum of the emitter signal and to combine the momentary frequency spectrum with the momentary position to generate source direction data comprising information on both the momentary frequency spectrum of the emitter signal and the momentary position of the rotary antenna.

Abstract: A network test instrument is operable to generate an interference profile for a bursty channel of a cable television network. Frequency spectrum data of a received signal is cross-correlated with predetermined frequency spectrum data to identify traces representative of noise. The interference profile may be built from the traces.

Abstract: An apparatus for radio direction finding, the apparatus comprising: a receiver configured to receive target signals to be subjected to the direction finding of signal sources, which are acquired by an antenna array; a channel profiler configured to produce profiles of the target signals received through the receiver; a pre-analyzer configured to preemptively process in a narrowband the wideband target signals based on the profiles that are produced by the channel profiler to produce pre-analyzed information for the wideband target signals; and a direction finder configured to perform the direction finding on the signal sources using the pre-analyzed information and the profilers of the target signals.

Abstract: A first antenna configured to receive a signal from each of a plurality of devices. A library contains at least one unique identifier for at least one target device. A second antenna is used to geolocate the target device once the first antenna locates it in the vicinity of the system. A processor is coupled to the first antenna to receive the signal from the plurality of devices and extract the unique identifier from the signal. The processor compares the unique identifier from the signal to the unique identifiers in the library. Upon a match, the second antenna is used to locate the target device.

Abstract: A method and apparatus to facilitate directional proximity detection by a wireless device. In one embodiment of the invention, the wireless device has a phased array antenna system that facilitates the directional detection of other wireless device(s). For example, in one embodiment of the invention, the phased array antenna system of the wireless device uses a radiation pattern beam that circumrotates the wireless device to detect the proximity and location of other wireless devices. In another example, in one embodiment of the invention, the wireless device uses a search strategy to optimize the process to detect the proximity and location of other wireless devices. The search strategy may adjust the radiation pattern beam to any desired angle to detect the proximity and location of other wireless devices.

Abstract: Method of using one or more transmitters and/or one or more parameters associated with a transmitter by using a reception station comprising a device suitable for measuring over time a set of K parameters dependent on the transmitters associated with vectors {circumflex over (?)}k representative of the transmitters for 1?k?K. The method includes a step of extracting the parameter or parameters consisting in grouping together by transmitter the parameters which are associated therewith by means of a technique of independent component analysis.

Abstract: An antenna device includes: an antenna base portion; an antenna mount portion which is supported by the antenna base portion and rotated around an azimuth axis and which supports a main reflector with two struts; a frame structure group including a plurality of frame structures which are provided in the antenna base portion and the antenna mount portion, with six degrees of freedom restrained, respectively; a displacement gauge group which measures a displacement of the frame structure group; a metrology correction portion which calculates a pointing error of an antenna based on measured data of the displacement gauge group and calculates a metrology correction amount by removing an error amount arising depending on an azimuth angle from the calculated pointing error; and a control circuit which controls a driving of the antenna by correcting a drive command value of the antenna with the metrology correction amount.

Abstract: Embodiments include systems and methods for controlling beam direction of an array of antenna elements in a wireless communications system. In one embodiment, aperture control shutters substantially cover each radiating antenna element. Each aperture control shutter is selectively turned on or off to control the direction of a beam of the antenna array.

Abstract: The invention relates to a method of localization of one or more sources, said source or sources being in motion relative to a network of sensors, the method comprising a step of separation of the sources in order to identify the direction vectors associated with the response of the sensors to a source having a given, incidence, characterized in that it comprises at least the following steps: associating the direction vectors a1m . . . aKm obtained for the mth transmitter and respectively at the instants t1 . . . tK, localizing the mth transmitter from the associated vectors a1m . . . aKm.

Abstract: In an interferometer system, a revolving antenna array is used to sufficiently resolve all ambiguities in determination of frequency and direction of arrival of a wave-front. The frequency and direction of arrival are determined by matching predicted phase difference codes with an actual code measured at the antenna array, utilizing a cross-correlation technique. The number of parameters that can be simultaneously uniquely determined by the system depends on if the antenna array is rotated in planar or conical surfaces, and if the cross-correlation is uni- or multi-dimensional. The antenna array may include more than one baselines to enhance the system sensitivity and finding capacity.

Abstract: A method and apparatus for reducing electromagnetic interference (EMI) and jamming in Global Positioning System (GPS) receivers operating on rolling or spinning platforms and/or environments is provided. An antenna system having a pair of diametrically-mounted elements provides interferometric cancellation for spatial and polarization nulling of interference signals. The antenna system, operating in conjunction with multiplexing and anti-jamming electronics, provides interference suppression for a GPS receiver connected thereto. Interference cancellation is provided in jamming and non-jamming environments by selectively employing spatial or polarization nulling of the interference signal.

Abstract: A system includes antenna control stations and a system interface. Each antenna control stations directs an orientation of an associated antenna to search for an identification signal associated with a mobile phone. The antenna control station communicates a detection response describing the orientation of the associated antenna. The system interface computes the location of the mobile phone based on the detection responses received from the antenna control stations.

Abstract: A system includes antenna control stations and a system interface. Each antenna control stations directs an orientation of an associated antenna to search for an identification signal associated with a mobile phone. The antenna control station communicates a detection response describing the orientation of the associated antenna. The system interface computes the location of the mobile phone based on the detection responses received from the antenna control stations.

Abstract: A detection apparatus is provided to detect the direction of arrival and the position of an emission source of radio wave with high accuracy.

Abstract: A detection apparatus is provided to detect the direction of arrival and the position of an emission source of radio wave with high accuracy.

Abstract: A system for locating the position of an emitter emitting a signal having time domain features is described. At least two platforms are used. Both have a receiver for detecting the emitter signal, an FFT channelizer to act as a bandpass filter for extracting the time domain features from the emitter signal, and a thresholder for thresholding the time domain signal. An FFT transform and a correlator using templates further extract frequency domain markers identifying the emitter. The frequency domain markers identifying the emitter are transmitted between platforms using a wireless link increasing the probability of detection of the emitter at all platforms.

Abstract: A system for locating the position of an emitter emitting a signal having time domain features is described. At least two platforms are used. Both have a receiver for detecting the emitter signal, an FFT channelizer to act as a bandpass filter for extracting the time domain features from the emitter signal, and a thresholder for thresholding the time domain signal. An FFT transform and a correlator using templates further extract frequency domain markers identifying the emitter.

Abstract: An object of the present invention is to provide a selective level measuring apparatus with wider dynamic range of effective value detection, compared with the range by a conventional one. The apparatus according to the present invention comprises a gain control means arranged before an effective value detection section for varying a gain by a control voltage, so that a signal level inputted into the effective value detection section may be kept to be constant level by the gain control means, and the signal level of the signal to be measured is measured and indicated through the control voltage. Performing such operations allows the selective level measuring apparatus for the effective value detection to secure a dynamic range defined by a variable quantity of the gain control means. Accordingly, the present invention provides the wider dynamic range of the effective value detection comparing with that by the conventional one.

Abstract: A digital electronic locator which assists in locating the position and direction of an object/animal/person is described. Three configurations of the locator are presented; the first one is the basic configuration which gives an alerting means (Audio and/or visual) to indicate the location of an object/animal/person, the second configuration of the locator, in addition to providing the facility offered by the basic configuration, indicates the direction of an object/animal/person, the third configuration of the locator is used for locating person, in addition to providing the facilities offered by the basic and the second configuration it provides the direction of the searcher to the person being located who can, as well, acknowledge that he/she has been found.

Abstract: A beam of a main antenna is scanned at a constant speed in the direction of compression of the beam width over the range of from (c-a) degree to (c+a) degree with an arbitrary angle c set as a reference angle, and a beam of a sub antenna is scanned by using a phase shifter at a constant speed in the direction of compression of the beam width over the range of from (c-b) degree to (c+b) degree where b represents an angle corresponding to the first zero point of a pattern of the sub antenna and larger than the 1/2 scan angle a of the main antenna. Received signals of both the antennas obtained by the beam scans are subjected to an in-phase multiplication process in a multiplying circuit for beam compression of the received pattern of the main antenna.

Abstract: Precise azimuth and elevation angles of arrival of a signal are determined using a rotating interferometer wheel rotatable about an axis parallel to the boresight of the interferometer. The angles of arrival are determined based on the measured phase differences of signals received by the interferometer, corresponding cone angles and the assignment of azimuth and elevation values to the group of conic lines which are nearest each other.

Abstract: Apparatus and methods of achieving accurate, unambiguous angle information with a minimum number of antenna elements. The present invention resolves the ambiguities inherent in a long baseline phase interferometer by employing a minimum number of antennas to form shorter baselines. The present invention employs roll motion (antenna rotation) to reorient interferometer baselines and a signal processor to measure the roll angle. Taking interferometer phase data with at least two orientations of the interferometer baselines permits resolution of the ambiguities. This also allows the use of long antenna baselines thereby achieving high angular accuracy with angle ambiguities resolved using only two antenna elements per spatial angle. This reduces system complexity and reduces the required clear aperture area, factors of great significance in missile systems. The invention takes phase data at two or more interferometer baseline orientations and forms a set of simultaneous equations involving the phase ambiguities.

Abstract: Method and apparatus for quickly determining the angle of arrival of a signal at a spinning interferometer based on the phase rate of changes and the cone angles between respective pulses received at the spinning interferometer.

Abstract: The invention relates to a surveillance sensor provided with at least one surveillance radar antenna 1 and at least one co-located and co-rotating electro-optical surveillance sensor 5 mechanically connected to said radar antenna. A combined panoramic picture is compiled by combining information from both sensors using a common track unit 30.

Abstract: An apparatus and method for determining the direction of origin of a received transmission signal using a spinning antenna pair generally provides the steps and apparatus for measuring the phase difference between signals simultaneously received, coarsely approximating the direction of origin of the transmission signal, reconstructing a phase difference signal using the measured phase differences and a calculated signal based upon the coarse approximation, correcting the reconstructed phase signal based upon the first derivatives of the reconstructed signal and the calculated signal, and determining the direction of origin based upon the corrected reconstructed phase signal.

Abstract: A receiver selects and amplitude demodulates an RF signal from one of a pality of directional antennas. The demodulated signal is then delayed to put it in time synchronism with the same signal information from an omnidirectional antenna. A signal is then generated of the peak pulses of the demodulated signal when the pulses are in time synchronism with pulses from the omnidirectional antenna. A control indicator receives the peak pulses along with periscope bearing signals and ship's heading signals and gives an r,.THETA. display of the amplitude of the RF signal selected from the directional antenna at the periscope true bearing angle.

Abstract: A direction finding method and apparatus utilizes two receiving antennas which are disposed on a baseline that is rotated around its midpoint at a constant angular velocity. Signals received from a transmitter by the antennas are processed by circuitry that includes a balanced mixer. The balanced mixer multiplies the signals from the two antennas, which are time varying and of different phase due to their rotation and spacing. The output from the balanced mixer is a signal which includes a high frequency component, and a low frequency component. The high frequency component can be used to determine incoming signal amplitude and frequency. The low frequency component can be used to determine the azimuth and elevation angles of the transmitter relative to the plane of rotation of the receiver through analysis of the signal at a number of different times.

Abstract: A target track data correlating decision in a multisensor system which decides whether the tracking data and observation data sent from a plurality of sensor sites are ones on the same target or different targets on the basis of the data. The correlation decision is implemented in a method and apparatus in such a manner that the likelihood ratios of parameters of the target track data are calculated and compared to decide whether the target is the same or not in accordance with a density distribution of each parameter of the data.

Abstract: A passive system and related methods for detecting range and/or elevation of a target by using an X beam antenna system and by measuring the time delay between receipt of signals in the two planes of the X beam which are received directly from the target and by measuring the time delay between receipt of signals in the two planes of the X beam which signals are emitted by the target but reflected from a remote surface. By knowing these two time delays, the height of the antenna system, the fixed angle between the two planes of the X beam and the rate of rotation of the X beam, a direct calculation is established to determine the range and/or elevation of the target.

Abstract: A passive system and related methods for detecting the location of a plurality of N targets by using two X-beam antenna systems and by (i) measuring the time delay between receipt of signals in the two planes of each X-beam which are received directly from the target and by (ii) measuring the time delay between the receipt of signals in the two planes of each X-beam which signals are emitted by the target but reflected from a remote surface. By known these two time delays for each antenna system, the heights of the antenna systems, the fixed angle between the two planes of the X-beam for each system, and the rate of rotation of the X-beam for each system, a direct calculation is established to determine the altitude of each target as viewed from each of the two antenna systems. Bearing or azimuth angles are determined for each target at each antenna system, and the actual N target locations of the N.sup.