Abstract: A system and method for a multi-beam multi-function active electronically scanned array (AESA) radar operation receives radar commands from individual aircraft systems and segments a single AESA fixed panel into a plurality of subarrays to carry out each individual function commanded by the individual aircraft system. Dependent on aircraft status and phase of flight, the subarrays are sized based on desired radar function at the specific phase of flight and specific threat associated with the phase. The system dynamically shifts the subarray size, beam characteristics, power settings, and function to enable multiple function of a cost effective single AESA panel.

Abstract: A vehicle radar system utilizes multiple radar sensors having overlapping fields of view to effectively synthesize a distributed radar antenna array aperture from the outputs of the multiple radar sensors and effectively enhance one or more of angular resolution, detection range and signal to noise ratio beyond that supported by any of the radar sensors individually.

Abstract: The disclosure relates to a radar arrangement for a motor vehicle, comprising at least one radar sensor with at least one antenna arrangement, wherein at least two antenna arrangements are arranged at a distance defined in an arrangement direction on a carrier component, which is permeable in particular to radar radiation, of the motor vehicle, and wherein the radar arrangement has a control device for common transmission and reception operation of the at least two antenna arrangements, such that these have the effect of a single virtual antenna arrangement with increased antenna extension in the arrangement direction.

Abstract: The invention provides a method for initial alignment of radar assisted airborne strapdown inertial navigation system. By calculating the slant distance and angular position between the radar and the airborne inertial navigation equipment, a nonlinear measurement equation for the initial alignment of the radar assisted inertial navigation system is obtained. The unscented Kalman filter algorithm is used to estimate and compensate the error amount of strapdown inertial navigation system to complete the initial alignment task. The significance of the present invention is to provide an in-flight initial alignment solution when the global positioning system is limited, which has fast convergence speed and high estimation accuracy and has high engineering application value.

Abstract: Systems, methods, and computer-readable media are described using radar systems to avoid vehicle collisions. An example radar system can include antennas mounted on an aircraft, where each antenna has a different orientation facing a different direction away from the aircraft. The radar system can include one or more processing devices and a computer-readable storage medium storing instructions which, when executed by the one or more processing devices, cause the radar system to coordinate digital beam steering and digital beam forming with the antennas to produce a radar coverage area that includes a portion of an airspace around the aircraft; detect, based a signal transmitted by the antennas using the digital beam steering and digital beam forming, an object within the radar coverage area; and generate collision avoidance information including an indication of the object detected within the radar coverage area and/or an instruction for avoiding a collision with the object.

Abstract: Radio frequency motion sensors may be configured for operation in a common vicinity so as to reduce interference. In some versions, interference may be reduced by timing and/or frequency synchronization. In some versions, a master radio frequency motion sensor may transmit a first radio frequency (RF) signal. A slave radio frequency motion sensor may determine a second radio frequency signal which minimizes interference with the first RF frequency. In some versions, interference may be reduced with additional transmission adjustments such as pulse width reduction or frequency and/or timing dithering differences. In some versions, apparatus may be configured with multiple sensors in a configuration to emit the radio frequency signals in different directions to mitigate interference between emitted pulses from the radio frequency motion sensors.

Abstract: A radar is provided which is mechanically and functionally independent of the primary radar; applies the principles of separation of emission pattern for each interrogation of any mode; of reception pattern for each reply of any mode; of assignment of the tasks which are specific thereto to distinct units. The radar includes one or more SSR/IFF interrogators dedicated at one and the same time to SSR surveillance and to gathering new mode S targets; and includes one or more other SSR/IFF interrogators for selective surveillance dedicated to mode S surveillance and to directed interrogations of IFF identification. The radar ensures simultaneous emission of the interrogations of the SSR/IFF interrogators in different azimuths, this simultaneous emission being enabled when the azimuthal spacing of the beams formed in emission ensures a decoupled level of jamming at the level of the transponders of the aircraft between the interrogations emitted by the respective sidelobes of the beams formed in emission.

Abstract: A radar sensor includes one transmitting antenna, multiple first receiving antennas with the same vertical heights, and a second receiving antenna with a vertical height different from the others. A method for determining the azimuth angle of an object with respect to the radar sensor includes steps of determining an approximation for the azimuth angle in a coarse grid based on the signals of all receiving antennas, and determining the azimuth angle in a fine grid based on the signals of the first receiving antennas in a range around the approximation.

Abstract: The present invention relates to a radar device for a vehicle which may determine a target as a single target or multiple targets according to a dispersion level of a slope for each reception channel, calculated through a phase difference for each reception channel of a reflection signal and an arrangement interval for each reception channel, and estimate the angle of the target so as to acquire the angle of the target using a small amount of calculations, and a method for estimating the angle of a target using the same.

Abstract: The present invention provides a block-based principal component analysis transformation method and a device thereof. The principal component analysis transformation method includes: obtaining an input signal; dividing the input signal and obtaining a plurality of one-dimension vectors corresponding to the divided input signal, wherein a number of the one-dimension vectors is a division number; after arranging the one-dimension vectors to a two-dimension vector, subtracting an average value of the one-dimension vectors of the division number to obtain a zero-mean vector; calculating a covariance matrix of the zero-mean vector; calculating an eigenvector of the covariance matrix; multiplying the zero-mean vector by the eigenvector to obtain a projection coefficient.

Abstract: An apparatus and method for processing a frequency offset of a pilot and a receiver where the includes: calculating a correlation function of a channel by using a receiving or received signal and a correlation length; calculating a phase to which the correlation length corresponds according to the correlation function; and calculating a corresponding slope according to phases to which at least two correlation lengths correspond when the phase to which the correlation length corresponds is greater than 2?, and estimating a frequency offset of a pilot of the channel based on the slope. Hence, estimation of a frequency offset of a pilot may be accurately achieved, thereby accurately judging channel spacing.

Abstract: A method is provided for use of a segmented aperture communications system to determine a direction of arrival of a radio signal in which the system includes a receiver plane having equally spaced and planar aligned radio frequency ports. Computation of the aperture segments depends on the port coordinates where the geometric relationship of the segments is used to determine a time delay and direction of arrival of the signal. The ports receive at least two orthogonal polarizations that characterize the incoming signals. A central port is used as reference to determine a phase difference associated at each port. Two angles are calculated by a simultaneous solution of two phase difference measurements to determine the direction of arrival solution. A mean direction of arrival solution is obtained by averaging solution estimates that are obtained by repeating the direction of arrival determination using random port pairs.

Abstract: A system and a method of generating a three-dimensional terrain model using one-dimensional interferometry of a rotating radar unit is provided herein. Height information is evaluated from phase differences between two echoes by applying a Kalman filter in relation to a phase confidence map that is generated from phase forward projections relating to formerly analyzed phase data. The radar system starts from a flat earth model and gathers height information of the actual terrain as the platform approaches it. Height ambiguities are corrected by removing redundant 2? multiples from the unwrapped phase difference between the echoes.

Abstract: A method for improving geolocation accuracy in a passive radar warning receiver, using synchronized data curve-fit and interpolation to asynchronous and noisy receiver and navigation measurements over observation periods that are extended to reduce inaccuracies caused by noise. The present disclosure yields synchronized data samples at intervals short enough that constant-rate equations are valid, even though the actual motions over the observation interval may be more complex and have higher-order dynamics. It reduces noise, synchronizes data samples, and is readily adapted to motions with variable acceleration. The method generates rate samples short enough to satisfy constant rate assumptions, yet fit data over intervals long enough to enhances measurement accuracy by reducing measurement noise.

Abstract: A logging method and a logging tool for approximating a logging tool response in a layered formation are provided. The method includes obtaining a first layered profile of at least one first measurement log provided by a logging tool using a squaring process, obtaining a filtered measurement log from the first layered profile using a forward physical model for the logging tool, and estimating an approximation of the forward physical model using a parameterized function so as to provide a first logging tool response.

Abstract: A method generates a 3D synthetic aperture radar (SAR) image of an area by first acquiring multiple data sets from the area using one or more SAR systems, wherein each SAR system has one or more parallel baselines and multiple pulse repetition frequency (PRF), wherein the PRF for each baseline is different. The data sets are registered and aligned to produce aligned data sets. Then, a 3D compressive sensing reconstruction procedure is applied to the aligned data sets to generate the 3D image corresponding to the area.

Abstract: A system and device phase-aligns and sums signals from a very large array of sensors, such as microphones or ultrasonic transducers, without prior knowledge of time delays of signals reaching each sensor, so as to accommodate effects of reverberant fields or acoustic or ultrasonic media containing multiple reflectors or scatterers and/or having heterogeneous, unknown acoustic properties.

Abstract: A product may receive each image in a stream of video image of a scene, and before processing the next image, generate information indicative of the position and orientation of an image capture device that captured the image at the time of capturing the image. The product may do so by identifying distinguishable image feature points in the image; determining a coordinate for each identified image feature point; and for each identified image feature point, attempting to identify one or more distinguishable model feature points in a three dimensional (3D) model of at least a portion of the scene that appears likely to correspond to the identified image feature point.

Abstract: Methods are provided for obtaining wideband waveforms from a set of narrowband waveforms. The synthesized wideband waveforms are suitable for generating fine range resolution synthetic aperture radar images. Furthermore, narrowband pulse compressed data can be siphoned from the processing chain to be used in multi-look GMTI processing either independently or jointly.

Abstract: The present invention relates to a method for acquiring SAR images for interferometric processing. The method comprises acquiring, by one or more airborne SAR sensors, SAR images of one and the same area with an acquisition geometry such that to enable interferometric processing of said SAR images. The method is characterized by an acquisition geometry in which each SAR image of the area is acquired in a respective direction of acquisition that defines a respective squint angle with respect to the direction of flight, and in which the squint angles are such that to determine a mean squint angle different from zero.

Abstract: A dual monopulse/interferometer antenna and radar system. In one example, the antenna includes an active electronically steered monopulse array, and is configurable into an interferometer mode which uses a subset of the array elements of each quadrant of the monopulse array. In one example, the RF feed network that combines signals received from each element in the array to produce monopulse return signals is modified in the interferometer mode to couple out the subset of array elements to produce return signals that are analyzed using interferometric processing.

Abstract: A projectile detection system, and method of detecting a projectile (for example a bullet), for use on a vehicle (100) (for example a helicopter), the projectile detection system comprising: a radar antenna array (4) arranged to transmit and receive microwave signals so as to provide a plurality of detection segments (40, 42, 44, 46) of a volume of airspace (38); one or more processors (3) arranged to: determine which segments (40, 42, 44, 46) microwave signals reflected by a projectile (10) are received from; determine timing information relating to a time order in which the received microwave signals are received; and determine directional information relating to a direction of travel of the projectile (10) using the determined segments (40, 42, 44, 46) and the determined timing information; wherein the microwave signals have a frequency between 1 GHz and 30 GHz.

Abstract: A system and a method of generating a three-dimensional terrain model using one-dimensional interferometry of a rotating radar unit is provided herein. Height information is evaluated from phase differences between two echoes by applying a Kalman filter in relation to a phase confidence map that is generated from phase forward projections relating to formerly analyzed phase data. The radar system starts from a flat earth model and gathers height information of the actual terrain as the platform approaches it. Height ambiguities are corrected by removing redundant 2? multiples from the unwrapped phase difference between the echoes.

Abstract: A multi-functional reconfigurable radar system and a method for configuring such a radar system are disclosed. The multi-functional reconfigurable radar system that is operable as a directional antenna or a DF interferometer. The antenna system in accordance with the present disclosure may be installed on a size-constrained platform such as an unmanned aerial vehicle (UAV) and utilized as a common shared asset aperture for intelligence-gathering, electronic countermeasure, self-protection, electronic support, electronic attack as well as direction finding and the like.

Abstract: A method for measuring three-dimensional coordinates of a probe center includes: providing a spherically mounted retroreflector; providing a probe assembly; providing an orientation sensor; providing a coordinate measurement device; placing the spherically mounted retroreflector on the probe head; directing the first beam of light from the coordinate measurement device to the spherically mounted retroreflector; measuring the first distance; measuring the first angle of rotation; measuring the second angle of rotation; measuring the three orientational degrees of freedom based at least in part on information provided by the orientation sensor; calculating the three-dimensional coordinates of the probe center based at least in part on the first distance, the first angle of rotation, the second angle of rotation, and the three orientational degrees of freedom; and storing the three-dimensional coordinates of the probe center.

Abstract: A system and method for a single site beacon transceiver including an omni-directional transceiver, a plurality of directional receiving antennas for receiving a signal, and a digital receiver for processing the signal to determine an azimuth to the source of the received signal. The digital receiver includes a plurality of receiver channels that are calibrated periodically and at least one processor that estimates a coarse signal azimuth for the signal by calculating an amplitude monopulse ratio for the signal using the two directional receiving antennas receiving the highest amplitude signal, and estimates a final signal azimuth for the signal using an interferometer baseline between the two directional receiving antennas or, alternately, subtracts the complex ratio of the measurements from the complex ratio of the antenna array RF model to determine the angle corresponding to the minimum of the absolute value of the difference.

Abstract: A method of using a directional sensor for the purposes of detecting the presence of a vehicle or an object within a zone of interest on a roadway or in a parking space. The method comprises the following steps: transmitting a microwave transmit pulse of less than 5 feet; radiating the transmitted pulse by a directional antenna system; receiving received pulses by an adjustable receive window; integrating or combining signals from multiple received pulses; amplifying and filtering the integrated receive signal; digitizing the combined signal; comparing the digitized signal to at least one preset or dynamically computed threshold values to determine the presence or absence of an object in the field of view of the sensor; and providing at least one pulse generator with rise and fall times of less than 3 ns each and capable of generating pulses less than 10 ns in duration.

Abstract: A system for providing a multi-mode, multi-static interferometer may include a transmitter array, a receiver array and a processor. The transmitter array includes at least a first transmitter and a second transmitter spatially separated from each other by a first known distance. The receiver array includes at least a first receiver and a second receiver spatially separated from each other by a second known distance. The receiver array is positioned to enable receipt of a return signal from transmissions provided by the transmitter array and reflecting off an object. The processor is configured to enable the transmitter array to generate uniquely coded signals and configured to distinguish, based on the uniquely coded signals, a first signal transmitted by the first transmitter from a second signal transmitted by the second transmitter in response to reception of a combined signal including reflected signals corresponding to at least the first and second signals by the receiver array.

Abstract: An electronic scanning radar apparatus mounted on a moving object includes a receiving unit including a plurality of antennas receiving a received wave arriving from a target having reflected a transmitted wave, a beat signal generating unit generating a beat signal from the transmitted wave and the received wave, a frequency resolving unit resolving the beat signal in beat frequencies and to calculate complex data based on the beat signal resolved for each beat frequency, and an azimuth detecting unit calculating a direction of arrival of the received wave based on original complex data calculated based on the beat signal, wherein the azimuth detecting unit includes a data extending unit generating extended complex data by extending the number of data based on the original complex data, and a first computation processing unit calculating the direction of arrival of the received wave based on the extended complex data.

Abstract: There is provided a radar apparatus for detecting a target. A detection signal generating unit generates detection signals of the target based on transmission and reception waves of antennas. A detection signal processing unit performs frequency analysis on the detection signals to extract signal components of the target, and performs a predetermined process on the signal components to calculate at least one of a distance to the target, a relative speed to the target, and an orientation of the target. The detection signal generating unit includes a filter unit for giving changes to the detection signals in a frequency bandwidth higher than Nyquist frequency which is a half a sampling frequency. The detection signal processing unit acquires the signal components from the detection signals to which the filter unit gives the changes to determine whether the signal components are generated by replication due to the Nyquist frequency.

Abstract: An on-board radar apparatus includes a plurality of reception antennas that form a reception array antenna that receives a reception wave obtained by causing an object to reflect a transmitted wave, the reception array antenna having two or more average pitches that do not have the relationship of integral multiplication, and an azimuth detecting unit configured to perform an azimuth detection process of detecting an azimuth of the target based on signals received by the respective reception array antennas, and to determine that the detected azimuth of the target is a real azimuth when it is determined that the azimuths of the target detected based on the signals received by the respective reception array antennas coincide with each other and to determine that the detected azimuth of the target is a pseudo azimuth when it is determined that the azimuths of the target detected based on the signals received by the respective reception array antennas do not coincide with each other.

Abstract: A obstacle detection system comprises a transmission antenna operable to radiate a radio frequency (RF) signal and a transmitter operable to control transmission of the RF signal from the antenna. The obstacle detection system also comprises a receiver antenna operable to receive a reflection of the RF signal; and processing circuitry operable to analyze a plurality of characteristics of a radar cross section (RCS) of the received reflection to identify an obstacle and one or more physical attributes of the obstacle.

Abstract: In an embodiment, a coordinate determiner is operable to identify at least first and second surfaces that each approximately intersect an object, and to determine at least two approximate coordinates of the object from the first and second surfaces, where at least one of the surfaces is nonplanar. For example, if the coordinate determiner is disposed on a fighter jet having at least two short-baseline-interferometers (SBIs), then two surfaces may be the surfaces of two cones having two of the SBIs as respective vertices, the object may be a close-in target, and the coordinate determiner may determine the azimuth and elevation of the target from the cone surfaces. Furthermore, the coordinate determiner or another computation unit onboard the jet may determine the slant range of the target from the elevation and the altitude of the jet.

Abstract: A non-scanning radar for detecting and tracking multiple moving objects. The transmit antenna continuously illuminates the entire surveillance volume, which can even be omni-directional (hemispherical). Multiple receive antennas are employed, each covering part of the surveillance volume. Receivers are used in combination to measure angles of incidence via interferometry on objects that are resolved in range and Doppler. Very long processing times are used to compensate for the reduced antenna gain compared to any radar that scans. By continuously illuminating the surveillance volume, there is no hard limit to the number of objects that can be simultaneously tracked. The primary application for this technology is detection and tracking of such objects as bullets, artillery projectiles, mortar shells, and rockets, and determining the location of the weapon that fired them. Numerous other applications are also described.

Abstract: A system and a method of generating a three-dimensional terrain model using one-dimensional interferometry of a rotating radar unit is provided herein. Height information is evaluated from phase differences between two echoes by applying a Kalman filter in relation to a phase confidence map that is generated from phase forward projections relating to formerly analyzed phase data. The radar system starts from a flat earth model and gathers height information of the actual terrain as the platform approaches it. Height ambiguities are corrected by removing redundant 2? multiples from the unwrapped phase difference between the echoes.

Abstract: An electronic scanning radar device that detects an azimuth angle of a target based on a phase difference between a first pair of received waves received by a first pair of antennas separated by a prescribed distance, and combines the first pair of received waves and generates a first composite wave. The composite wave has a steep antenna pattern, for which the amount of level change is large for the amount of change in azimuth angle, and an azimuth angle judgment unit performs true/false judgment in which a detected azimuth angle is judged to be true when the level of the above first composite wave is equal to or above a reference value, and the azimuth angle is judged to be false when the level is below the reference value.

Abstract: A synthetic-aperture radar system, and related operating method, for the monitoring of ground and structure movements, particularly suitable for emergency conditions, characterized by a ground based platform with polarimetric capabilities, that able to quickly acquire, embeddedly process and post-process data by a novel data acquisition “On the Fly” mode of operation, reducing by at least an order of magnitude the data acquisition time. The inventive system characteristics allows to achieve on-field measurement results on three-dimensional maps georeferenced to absolute coordinate systems (WGS84, Gauss-Boaga, and so on).

Abstract: A detection and tracking radar includes a hazardous zone set within a preset radius based on a main body having a radar, a plurality of detection and tracking sectors configured to detect a high speed mobile approaching the main body within detection areas, the detection areas being defined by diving the hazardous zone based on an azimuth angle, and a controller configured to recognize the high speed mobile as a target based upon signals received from the detection and tracking sectors and track the target. Accordingly, rapid detection and tracking of the high speed mobile can be allowed. Also, since the detection and tracking sectors can be independently run, expansion of a radar system can be free by virtue of addition of the detection and tracking sectors.

Abstract: Interferometric angle-of-arrival (AOA) ambiguities due to local multipath reflections are resolved by measuring the received phase differences of one or more pairs of antenna elements of the interferometer array, constructing hypotheses from unwrapped phase pairs that correspond to potential AOA solutions, and selecting the hypothesis that most likely represents the true AOA of the signal emitter based on processed unwrapped data that has been corrected through the application of a priori calibration terms selected on the bases of the candidate hypotheses.

Abstract: An apparatus and method for receiving electromagnetic waves using photonics includes a transmission unit transmitting electromagnetic waves in intervals; a time delay unit coupled to the transmission unit and controlling the transmission unit to transmit the electromagnetic waves in the intervals; an antenna receiving the electromagnetic waves reflected from the target; an interferoceiver coupled to the antenna and receiving the electromagnetic waves from the antenna, the interferoceiver comprising an optical recirculation loop to produce replica electromagnetic waves; and a computer identifying the target from the reflected electromagnetic waves.

Abstract: In an embodiment, a quantity smoother includes a first stage and a second stage. The first stage is operable to receive a sequence of raw samples of a quantity and to generate from the raw samples intermediate samples of the quantity, the intermediate samples having a reduced level of fluctuation relative to the sequence of raw samples. The second stage is coupled to the first stage and is operable to generate from the intermediate samples resulting samples of the quantity, the resulting samples having a reduced level of fluctuation relative to the sequence of intermediate samples. For example, such a quantity smoother may be part of a target-ranging system on board a fighter jet, and may smooth an error in an estimated target range so that the fighter pilot may more quickly and confidently determine in his head a range window within which the target lies.

Abstract: The present disclosure relates to a method for monitoring targets on a runway, wherein emitting modules and receiving modules are alternately distributed along each one of longitudinal sides of the runway. Orthogonal signals are emitted in a narrowband by the emitting modules and coherently received in a coherent manner by the receiving modules. An object is detected on the runway on the basis of a distribution of the modules into meshes each including three pairs of neighbouring emitting modules and receiving modules and on the basis of a radio location of the object through triangulation and interferometry in at least one mesh. The modules are also used for analyzing a target moving on the runway, and for monitoring the trajectographies of an air target in the surroundings of the runway.

Abstract: Interferometric angle-of-arrival (AOA) ambiguities due to local multipath reflections are resolved by measuring the received phase differences of one or more pairs of antenna elements of the interferometer array, constructing hypotheses from unwrapped phase pairs that correspond to potential AOA solutions, and selecting the hypothesis that most likely represents the true AOA of the signal emitter based on processed unwrapped data that has been corrected through the application of a priori calibration terms selected on the bases of the candidate hypotheses.

Abstract: A method for interferometric radar measurements that provides prearranging, at a target observed by the radar, of a transponder that is adapted to perform a frequency shift fd of a radar signal received by the target, and to retransmit a response signal towards the radar. The frequency-shift is such that the signal (21), as received by the radar, can be separated from clutter (19) coming from the radar scenario, by a demodulation step (A), in particular a coherent demodulation step, and a phase extraction step (B), which may comprise a further demodulation step by a phasor that has a frequency equal to fd. If these steps are carried out subsequently, it is possible to calculate the phase difference with respect to signals 22 and then measuring the displacement that target (2) carries out between such instants.

Abstract: The present invention relates to a radar device with high angular accuracy. The solution provided by the invention simultaneously combines an interferometer that is accurate but, for example, ambiguous when receiving; and a space colouring mode when transmitting. The colouring of the space consists notably in transmitting on N transmitting antennas N orthogonal signals. These signals are then separated by filtering on reception using the orthogonality properties of the transmission signals. It is, for example, possible, with two contiguous antennas in transmission associated with two orthogonal codes to produce a single-pulse type system when transmitting. The invention applies notably to the obstacle sensing and avoidance function, also called “Sense & Avoid”.

Abstract: In an embodiment, a coordinate determiner is operable to identify at least first and second surfaces that each approximately intersect an object, and to determine at least two approximate coordinates of the object from the first and second surfaces, where at least one of the surfaces is nonplanar. For example, if the coordinate determiner is disposed on a fighter jet having at least to short-baseline-interferometers (SBIs), then two surfaces may be the surfaces of two cones having two of the SBIs as respective vertices, the object may be a close-in target, and the coordinate determiner may determine the azimuth and elevation of the target from the cone surfaces. Furthermore, the coordinate determiner or another computation unit onboard the jet may determine the slant range of the target from the elevation and the altitude of the jet.

Abstract: A system and method for a single site beacon transceiver including an omni-directional transceiver, a plurality of directional receiving antennas for receiving a signal, and a digital receiver for processing the signal to determine an azimuth to the source of the received signal. The digital receiver includes a plurality of receiver channels that are calibrated periodically and at least one processor that estimates a coarse signal azimuth for the signal by calculating an amplitude monopulse ratio for the signal using the two directional receiving antennas receiving the highest amplitude signal, and estimates a final signal azimuth for the signal using an interferometer baseline between the two directional receiving antennas or, alternately, subtracts the complex ratio of the measurements from the complex ratio of the antenna array RF model to determine the angle corresponding to the minimum of the absolute value of the difference.

Abstract: The present invention relates to a method for determining the position notably the elevation of a target flying at very low altitude. An electromagnetic detection system extracts the measurement of the elevation on the basis of the amplitude of the interference signal produced by a signal emitted directly by the target and by a signal emitted by the target towards the ground then reflected by the ground towards the radar. Embodiments of the invention can notably be used within the framework of the guidance of drones in the final landing phase.

Abstract: Narrow virtual transmit pulses are synthesized by differencing long-duration, staggered pulse repetition interval (PRI) transmit pulses. PRI is staggered at an intermediate frequency IF. Echoes from virtual pulses form IF-modulated interference patterns with a reference wave. Samples of interference patterns are IF-filtered to produce high spatial resolution holographic data. PRI stagger can be very small, e.g., 1-ns, to produce a 1-ns virtual pulse from very long, staggered transmit pulses. Occupied Bandwidth (OBW) can be less than 10 MHz due to long RF pulses needed for holography, while spatial resolution can be very high, corresponding to ultra-wideband (UWB) operation, due to short virtual pulses. X-Y antenna scanning can produce range-gated surface holograms from quadrature data. Multiple range gates can produce stacked-in-range holograms. Motion and vibration can be detected by changes in interference patterns within a range-gated zone.

Abstract: Systems and methods of error handling in interferometric signal processing for a ground based slope monitoring system are described. Uncorrected movement data is extracted from interferometric radar measurements of a relatively stable reference. The movement data is corrected for changes in atmospheric conditions as a function of changes in a refractive index of the air and an offset induced at zero range.