Abstract: A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective direction coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed to receive reflected microwave illumination reflected from the position on the target. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.

Abstract: Disclosed are a method and system for improving real-time determination of flight parameters of an aircraft during flight. A selection module selects and delivers measured values of input parameters to an estimation unit, and the estimation unit uses the input parameters to estimate at least two selected flight parameters. The input parameters are received by the estimation unit on the basis of identified flight mechanics equations associated with the selected flight parameters. The estimation unit includes an extended Kalman filter, which is configured to receive the values of the input parameters and to output joint estimations of the selected flight parameters based on the flight mechanics equations, during the flight of the aircraft.

Abstract: The invention provides a security scanner that produces a radar profile of a clothed person or another object such as a bag carried by a person at a distance and does not require close proximity of the person or object to the scanner itself. The scanner includes a millimeter wave antenna system optimised for short-range active imaging and arranged to provide rapid high-resolution images of an object or person of interest and processing means for resolving the images so as to detect the presence of predetermined objects. The processing means preferably includes means for comparing contrasts in reflectivity in the scanned images with predetermined expected values from skin and light clothing. The processing means may also include means for detecting predetermined behavioral or physical traits such as the effect on gait on carried weighty objects or stiff structures strapped to the person from the images of a scanned object or person. The scanner may be incorporated within a turnstile access arrangement.

Abstract: Systems and methods for improving situational awareness on an in-trails procedures display. A radar system transmits a radar signal and receives and stores weather radar reflectivity values into a three-dimensional buffer. A processor determines whether any of the stored weather reflectivity values indicate the presence of a weather hazard and generates one or more weather hazard icons based on the stored weather reflectivity values. An in-trail procedures display device displays the generated weather hazard icons. Wake vortex information for other aircraft is generated and outputted on the in-trail procedures display. Also, the processor receives a request for an altitude change and generates an alert when the aircraft is determined not to be cleared to transition to the requested altitude based on a projected transition, any existing weather hazards, wake vortices of proximate aircraft, and in-trail procedures.

Abstract: This disclosure provides a signal processing device, which includes an echo signal input unit for being inputted with echo signals caused by electromagnetic waves discharged from an antenna and reflected on one or more target objects, an echo signal level detector for detecting a level of each of the echo signals with reference to an azimuth and a distance to the antenna, a level change detector for detecting a level change between the echo signals from locations close to each other, the locations of the echo signals being such that the distances from the antenna are substantially the same but the azimuths are different, a pattern output module for comparing the level change with a predetermined reference pattern and outputting a level change pattern, and a missing determining module for determining a missing of a signal based on at least two of the level change patterns.

Abstract: Frequency swept radar signals are transmitted from a plurality of transmitter antennas with predetermined timing offsets between the frequency sweeps of respective ones of the transmitters. A combination of reflections of the transmitted frequency swept radar signals is received. A filter bank separates a plurality of beat signals from respective frequency bands in the received combination of reflections. Transmitter antennas at respective different spatial locations may be used and intermediate signals derived from the separated beat signals may be summed to form a synthetic aperture radar image.

Abstract: The present invention relates to the general field of radar tracking applied to multi-static radar systems. It consists of a method for coherently merging the individual tracks generated from the various bistatic bases that make up the system so as to generate and maintain global tracks so that an object detected by a single bistatic base is represented by the corresponding track and an object detected by a number of bistatic bases and giving rise to the creation of a number of individual tracks is represented only by a single global track.

Abstract: A method and an arrangement are provided for producing a computed distribution of speeds of scatterers in a target volume (1701). An estimate distribution of speeds at which scatterers would move in the target volume is provided (1201). It is converted (1202) to a candidate autocorrelation function that represent autocorrelation data points that a pulse radar would measure from the current estimate distribution. The fit of a candidate ACF to a measured ACF is measured (1203). The estimate distribution is accepted if a measured fit fulfills a predefined acceptance criterion, or modified (1205) in which case processing returns to the conversion of the modified estimate distribution to an ACF. An accepted estimate distribution is output (1206) as a computed distribution of speeds that describes the actual distribution of speeds.

Abstract: A method for considering an echo amplitude profile as a result of convoluting a single echo with a channel response sequence, wherein for multiple echo detection, an estimation task is broken into three major steps comprising estimating a channel response, recovering a full shape of a single echo, and iteratively updating the channel response and echo shape to increase their accuracy. The estimation of the channel response is treated as a single echo detection problem and includes estimating the strongest echo for its position and amplitude, removing an echo corresponding to this recovered channel from the echo amplitude profile, and repeating the preceding steps for the next strongest echo.

Abstract: There is provided a waveguide connecting structure, including first, second, third and fourth waveguides. A first coupling window at one of magnetic field planes of the third waveguide couples the first and third waveguides in such a manner that the electric field planes of both are in parallel. A second coupling window formed at one of the electric field planes of the third waveguide couples the second and third waveguides in such a manner that the electric field planes of the second waveguide is in parallel with the magnetic field planes of the first waveguide. A third coupling window formed at the other one of the electric field planes couples the fourth and third waveguides in such a manner that the electric field planes of the fourth waveguide is in parallel with the magnetic field planes of the first waveguide.

Abstract: The present invention provides a method for separating, or de-interleaving, a stream of radar pulses, interleaved in time, received by a receiving antenna (10) and receiver (12) from several radar sources. De-interleaving the stream of received pulses may include forming clusters of pulses having similar parameter values around anchor points, where each cluster is defined by a window around its anchor point. The dimensions of each window may be determined by a weighted distance, i.e., a measure of dissimilarity, calculated using weights. Each weight may depend inversely on the measurement error in the parameter with which the weight is associated. Each anchor point may have a set of weights adjusted to its parameter values, and which may change as operating conditions change. The weights may be determined using a method including a calibration step, which may include injecting pulses with known parameters into the receiver (12).

Abstract: A radar or sonar system amplifies the signal received by an antenna of the radar system or a transducer of the sonar system is amplified and then subject to linear demodulation by a linear receiver. There may be an anti-aliasing filter and an analog-to-digital converter between the amplifier and the linear receiver. The system may also have a digital signal processor with a network stack running in the processor. That processor may also have a network interface media access controller, where the system operates at different ranges, the modulator may produce pulses of two pulse patterns differing in pulse duration and inter-pulse spacing, those pulse patterns are introduced and used to form two radar images with the two images being derived from data acquired in a duration not more than twenty times larger than the larger inter-pulse spacing, or for a radar system, larger than one half of the antenna resolution time. One or more look-up tables may be used to control the amplifier.

Abstract: A method for transmission and detection in an adaptive-on-transmit (AT) system operating in the electromagnetic spectrum comprising determining a waveform-filter pair; and employing the waveform-filter pair in transmission and detection, wherein two or more are provided of the group consisting of an auto-correlation function sidelobe level reduction proportional to a the filter length, K, or better, an out-of-band spectral suppression of at least about 40 dB, and a frequency spectrum power tail power decay of K?4 or better.

Abstract: A system for engaging hostile air or space threats with a defensive missile, where the defensive missile comprises an antenna for receiving global positioning system (GPS) signals. A global positioning system receiver is coupled to said antenna, for receiving global positioning system signals directly from global positioning system satellites and global positioning system signals reflected from the threat. A processing arrangement processes the direct and reflected global positioning system signals for determining the position and velocity of the threat. Vectoring controls are coupled to the processing arrangement, and are responsive to the location of the threat for directing the defensive missile toward the threat. In a particular embodiment, the antenna of the defensive missile is directionally controllable, and the defensive missile includes an antenna direction controller responsive to the processor for directing at least a beam of the antenna toward the threat.

Abstract: A method and apparatus is devised for detecting objects of interest in which frequency-scanned RF in the HF region of the electromagnetic spectrum is projected out across a given area and returns are detected and converted into image data in which phase, amplitude, range and frequency associated with the incoming data is correlated with frequency-dependent range templates to determine the existence of, the range of and the direction of the objects of interest.

Abstract: A passive radar device includes: a pulse-by-pulse range compression unit executing cross-correlation processing between received signals of a direct wave and scattered wave on each of pulses divided by a direct-wave reception unit and a scattered-wave reception unit, and calculating a pulse-by-pulse range profile; a block-by-block Doppler processing unit calculating a first Doppler frequency spectrum by executing pulse-direction Fourier transform in block units each grouping plural pulses; a Doppler frequency cell-associated range migration compensation unit compensating a range-direction movement amount with respect to the first Doppler frequency spectrum on a Doppler-frequency-cell-by-Doppler-frequency-cell basis and on a block-by-block basis; and a block-direction Doppler processing unit calculating a second Doppler frequency spectrum by executing block-direction Fourier transform on an output from the Doppler frequency cell-associated range migration compensation unit.

Abstract: A sensor system uses ground emitters to illuminate a projectile in flight with a polarized RF beam. By monitoring the polarization modulation of RF signals received from antenna elements mounted on the projectile, both angular orientation and angular rate signals can be derived and used in the inertial solution in place of the gyroscope. Depending on the spacing and positional accuracies of the RF ground emitters, position information of the projectile may also be derived, which eliminates the need for accelerometers. When RF signals of ground emitter/s are blocked from the guided projectile, the sensor deploys another plurality of RF antennas mounted on the projectile nose to determine position and velocity vectors and orientation of incoming targets.

Abstract: A new approach to radar imaging is described herein, in which radar pulses are transmitted with an uneven sampling scheme and subsequently processed with novel algorithms to produce images of equivalent resolution and quality as standard images produced using standard synthetic aperture radar (SAR) waveforms and processing techniques. The radar data collected with these waveforms can be used to create many other useful products such as moving target indication (MTI) and high resolution terrain information (HRTI). The waveform and the correction algorithms described herein allow the algorithms of these other radar products to take advantage of the quality Doppler resolution.

Abstract: A method includes inputting an echo signal from an antenna for discharging an electromagnetic wave to a predetermined area and receiving an echo signal reflected on a target object, outputting a level of the echo signal from every location so as to associate the level with a distance from the antenna in an azimuth direction where the electromagnetic wave is discharged, calculating a degree of change in the level of the echo signal from mutually adjacent locations among all the locations concerned, performing edge emphasis processing for the level of the echo signal in the azimuth direction based on the degree of change and outputting an edge-emphasized echo signal, and performing scan-to-scan correlation processing to calculate a correlation value of the echo signals of two or more scans using the edge-emphasized echo signals, where the echo signals from the entire predetermined area is used as one scan.

Abstract: A method for onboard determination of a roll angle of a projectile. The method including: transmitting a polarized RF signal from a reference source, with a predetermined polarization plane; receiving the signal at a pair of polarized RF sensor cavities positioned symmetrical on the projectile with respect to a reference roll position on the projectile; measuring a difference between an output of the pair of polarized RF sensor cavities resulting from the received signal to determine zero output roll positions of the projectile; and comparing an output of the pair of polarized RF sensor cavities at each of the zero output positions to determine when the projectile is parallel to the predetermined polarization plane. The method can also include analyzing an output of at least one third sensor positioned on the projectile to determine whether the roll angle position of the projectile is up as compared to the horizon.

Abstract: A method, a system and a program product for deinterleaving and classifying an incoming unknown radar pulse pattern uses a library of state machines that mesh with a library of known radar pulse patterns of a library of known radar emitter sources. A continuous sequence of radar pulse descriptor words is secured for the incoming unknown radar pulse pattern and a plurality of state machines that may mesh with the continuous sequence of radar pulse descriptor words is selected from the library of state machines. The plurality of state machines that may mesh with the incoming unknown radar pulse pattern is operated upon the incoming unknown radar pulse pattern. Radar emitter sources that correlate with state machines that actually mesh with the incoming unknown radar pulse pattern are designated as radar emitter sources that comprise the incoming unknown radar pulse pattern.

Abstract: Embodiments of a guidance section that compensates for boresight error (BSE) caused by effects of a composite radome. The guidance section includes a BSE compensation element to add high-pass filtered noise to compensated BSE data. The guidance section also includes and a Kalman filter to generate line-of-sight rate (LOSR) BSE noise from the compensated BSE data and the added high-pass filtered noise. In some embodiments, a method for generating a revised BSE correction matrix is provided. The revised BSE correction matrix may compensate for BSE caused by effects in the composite radome and may correct for relative target velocity error.

Abstract: A method of detecting a target in a room using a radar system having a transmitter for irradiating the object, a sensor for receiving reflected radiation, and circuitry for analyzing the reflected radiation to determine at least one characteristic thereof, the method including determining at least one parameter for each wall of a plurality of walls of a room containing the target; determining possible signal paths between the target and the sensor for paths including up to N reflections based on the at least one parameter of each wall and the location of the sensor; calculating target image locations based on the possible signal paths; and processing the received radiation to determine a target location based on target image locations.

Abstract: A SAR image recorded by a reconnaissance system is transferred as a reference edge image together with the data of the trajectory as a reference. The signal of the infrared seeker head of the missile is converted into a virtual SAR edge image and compared to the SAR reference image to calculate the precise position of the missile.

Abstract: A method for constructing focused radar images includes chopping the radar illumination period into p sub-periods, two successive sub-periods overlapping temporally; choosing n successive sub-periods from among the p sub-periods, and for each of the n chosen sub-periods, performing radar acquisitions to generate an image IM_0x of resolution R0; and applying an autofocus processing to each of the n images IM_0x generated; combining the n images so as to generate at least one new focused radar image IM_1x. The method is applied notably to the production of high-resolution SAR images with the help of an aircraft equipped with a radar antenna.

Abstract: A method of determining an angle within the beam to a target using an airborne radar includes receiving first data associated with first returns associated with a first portion of an antenna. The method further includes receiving second data associated with second returns associated with a second portion of an antenna, wherein the first portion is not identical to the second portion. The method further includes determining the angle within the beam to the target using the first and second data.

Abstract: A method for detecting precipitation in a region monitored by radar beams includes ascertaining a first average power of a first backscattered radar signal, ascertaining a second average power of a second backscattered radar signal, and detecting an existence of a homogenous medium when the average powers conform.

Abstract: The invention provides a pulse radar apparatus, and a control method thereof, that permits to readily downsize and to lower its cost and allows information on an object to be detected in high precision by removing an influence of noise when a gain of a variable gain amplifier is discontinuously changed corresponding to detected distance, with a simple configuration. A variable gain amplifier 135 configured to adjust a gain corresponding to a distance gate is used to be able to detect weak reflected wave from a distant object and to amplify a reflected wave from a short distance with a low gain. An offset noise from the variable gain amplifier 135 is prepared together with interference noise and self-mixing noise in advance as a replica signal of unwanted wave and the replica signal is removed from a baseband signal in detecting the object T.

Abstract: Electromagnetic wave structure modulation apparatus comprises an encoded device that has an electromagnetic wave-transparent material having a three-dimensional volume and electromagnetic wave-opaque walls, and a plurality of electromagnetic wave-opaque projections projecting into the electromagnetic wave-transparent material. The apparatus further comprises an interrogating device that has a transceiver operable to transmit an electromagnetic wave into the electromagnetic wave-transparent material, the electromagnetic wave being modulated and reflected by the electromagnetic wave-opaque walls and projections, an antenna operable to receive the reflected electromagnetic waves, and a decoder operable to decode the received reflected electromagnetic waves.

Abstract: A method and device for recognizing a pulse repetition interval (PRI) modulation type of a radar signal are provided. The method for recognizing a pulse repetition interval (PRI) modulation type includes: extracting time of arrival (TOA) information of pulses aligned in time order from a received radar signal; generating a PRI sequence based on a difference of adjacent TOAs in the TOA information of pulses; generating a difference of PRIs (DPRI) sequence by using a difference of the adjacent PRIs in the PRI sequence; generating respective symbol sequences by using specific partition rules from the PRI sequence and the DPRI sequence; and calculating characteristic factors from the symbol sequences, and comparing the characteristic factors with threshold values for discriminating a PRI modulation type to determine the PRI modulation type. Thus, the PRI modulation type, a promising feature for radar signal identification, can be precisely derived.

Abstract: The present disclosure describes a method and system for detecting and determining the position of a target or intruder using a plurality of sensors positioned throughout a secured perimeter and a single antenna. The system of the present disclosure detects and determines the position of a target by first analyzing the return signal strength values of each of the sensors. Next, Zvalues for each of the sensors are calculated. Based on the Zvalues, certain sensors are selected to compute a signal strength center-of-mass location, which is then used to determine the position of the target.

Abstract: A dual mode ground penetrating radar includes an enclosure which houses radar electronics. The dual mode ground penetrating radar includes a enclosure housing radar electronics. The dual mode ground penetrating radar further includes a first antenna feed having ferrite loading and extending outside of the enclosure. The dual mode ground penetrating radar further includes a second antenna feed spaced apart from the first antenna feed, the second antenna feed having ferrite loading and extending outside of the enclosure. An RF signal is provided in at least one of the first and second antenna feeds by the radar electronics.

Abstract: A motion detector system includes the ability to detect motion through the use of a Doppler radar sensor or a combination of PIR sensors and a Doppler radar sensor. The system includes an outdoor light fixture having one or more lamps and a housing coupled to the outdoor light fixture. The housing includes a Doppler radar sensor and a microprocessor for analyzing the signals received by the Doppler radar sensor. Alternatively, the housing includes a combination of PIR sensors and a Doppler radar sensor and a microprocessor for analyzing the signals received from these sensors. The lamps in the light fixture are activated when either the PIR sensor or the Doppler radar sensor generates a signal indicating motion within the monitored area. Alternatively, the lamps can be activated when either the PIR sensor or the Doppler radar sensor senses predetermined number of motion activities over a limited time period.

Abstract: The invention relates to a system and method for detecting, locating and identifying objects located above ground or below ground in an area of interest, comprising an airborne vehicle which circumscribes the area of interest and which includes a built-in radar having an antenna with a respective transmitter and receiver, signal-processing means, data-storage means and graphical interface means. According to the invention, the area of interest has been pre-referenced and the radar is a heterodyne ground penetration radar (GPR). The signal transmitted by the antenna generates a beam that illuminates a strip of earth, consisting of a sinusoidal electromagnetic signal having a frequency that is varied in precise pre-determined progressive steps. This signal is mixed with the received (reflected) signal, thereby producing two sets of values corresponding to the phases of each frequency step or stage.

Abstract: A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Abstract: A system and technique for imaging a subject at a scene overcomes the weaknesses in the existing gain fluctuation techniques by switching the environmental temperature at the scene at a rate sufficiently fast enough to obtain subsequent samples in a time period where the gain has not fluctuated sufficiently to have a negative effect on detection sensitivity. This technique is utilized in conjunction with the method of subsequent subtraction of alternate samples which both reveals the reflectance of the scene and removes gain fluctuation.

Abstract: In the case where radar image data obtained from a radar device equipped in a flying body and optical image data of a district taken by the radar device are synthesized to produce a terrestrial object information judging image, the radar image data are approximated to a black and white panchromatic image character. The radar image data approximated to the black and white panchromatic character and the optical image data are aligned in position and then synthesized. As a suitable embodiment, in an approximation processing of the radar image data to the black and white panchromatic image character, histogram conversion processing is carried out in accordance with a histogram characteristic of the radar image data.

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: A radar device includes a signal generator that generates an intermittent signal having a prescribed signal width and signal interval, a transmission signal position adjuster that outputs a transmission signal while adjusting positions of the intermittent signal on the time axis, an RF transmitter that transmits the transmission signal, an RF receiver that receives a reception signal including reflection waves reflected from an object in a measurement subject space, an AD converter that converts the reception signal into a digital signal, and an object detector that detects the object based on the reception signal. The transmission signal position adjuster outputs a transmission signal in which positions of respective signal units of the intermittent signal on the time axis are adjusted in units of a time adjustment amount that is shorter than a sampling interval of the AD converter.

Abstract: A method of radar-imaging a scene in the far-field of a one-dimensional radar array, comprises providing an array of backscatter data D(fm, x?n) of the scene, these backscatter data being associated to a plurality of positions x?n, n=0 . . . N?1, N>1, that are regularly spaced along an axis of the radar array. The backscatter data for each radar array position x?n are sampled in frequency domain, at different frequencies fm, m=0 . . . M?1, M>1, defined by fm=fc?B/2+m??f, where fc represents the center frequency, B the bandwidth and ?f the frequency step of the sampling. A radar reflectivity image 1 (?m?, ?n?) is computed in a pseudo-polar coordinate system based upon the formula (2) with formula (3) where j represents the imaginary unit, formula (A) is the baseband frequency, FFT2D denotes the 2D Fast Fourier Transform operator, ?m?, m?=0 . . . M?1, and ?n?, n?=0 . . .

Abstract: Methods and systems are disclosed for radar pulse compression signal processing. Methods include generating a function that quantifies radar signal characteristics and using a processor to calculate time-domain derivatives of the function in the frequency domain. Methods also include generating a function that quantifies radar signal characteristics as a sum of sidelobe levels; and using a processor to control the sidelobe levels by obtaining gradients of the function in the spectral domain.

Abstract: Active RFID technologies are used to tag assets and people within buildings or open areas, such as parking lots or military bases; and to identify, preferably within a few meters, the real-time location (RTL) of the tag, i.e. to create a real-time location system, known as an RTLS. A novel and complex algorithm is provided that combines signal strength computations with factors that incorporate physical realities, such as walls and floors, to determine a tag's real-time location more accurately.

Abstract: In one aspect, a method includes tagging a track as a live track if a tagging statistic is greater than a tagging statistic threshold and tagging the track as a virtual track if the tagging statistic is less than the tagging statistic threshold. In another aspect, an article includes a machine-readable medium that stores executable instructions to determine whether a track is a live track or a virtual track. The instructions causing a machine to tag a track as a live track if a tagging statistic is greater than a tagging statistic threshold and tag the track as a virtual track if the tagging statistic is less than the tagging statistic threshold. In a further aspect, an apparatus includes circuitry to tag a track as a live track if a tagging statistic is greater than a tagging statistic threshold and tag the track as a virtual track if the tagging statistic is less than the tagging statistic threshold.

Abstract: Disclosed herein is a method of sensor network localization through reconstruction of a radiation pattern with a characteristic value of an antenna depending on orientation thereof. The method can minimize errors using an antenna characteristic value and a signal strength depending on the orientation. In addition, the method can minimize errors using an artificial neural network to characterize a distorted radiation pattern of an antenna and using it for the localization of a triangulation method. Furthermore, the method can increases the localization rate even in a passive localization method by characterizing an asymmetric antenna radiation pattern and constructing the antenna characteristic through an artificial neural network.

Abstract: A method and system for detecting chaff is disclosed. The method includes receiving range profile data including a plurality of samples, determining an average power for a first group of samples of the range profile data and a second group of samples of the range profile data, comparing the average power for the first group of samples to a first threshold value and the average power for the second group of samples to a second threshold value, and identifying a chaff detection if an average power of at least one of the first and second groups of samples exceeds its respective threshold value. The system includes a computer readable medium and a processor in communication with the computer readable storage medium and configured to perform the receiving, determining, comparing and detecting steps.

Abstract: A method for determining a location of a flying target included identifying and measuring the target by at least two seeker systems disposed at a distance from one another. The position of the target relative to at least one of the two seeker systems is determined from measurement data derived therefrom. The position of the target is measured inconspicuously and without active radiation, in that the seeker systems are data-networked, passive target tracking systems for missiles, which autonomously track the target and align the missile with the target. The measurement data determined by the data-networked seeker systems are combined, and the location of the target is determined from the combined data.

Abstract: An object ranging system operates by transmitting pulses derived from a frequency-swept signal and determining the beat frequency of a combination of the frequency-swept signal and its reflection from an object. A second (or higher) order harmonic is derived from the combination signal. Accordingly, determination of the beat frequency, and hence object range, is significantly enhanced. The frequency sweep is such that frequency changes occur at a substantially higher rate at the beginning of each the pulse repetition interval than at the end. Accordingly, because the frequency changes are concentrated in the period of pulse transmission, even reflections 'from a close object, where the time delay between the source signal and the reflection is very short, will cause a high beat frequency.

Abstract: Systems and methods for representing a weather hazard without also including a large percentage of non-hazard area. An exemplary system includes a memory that stores radar reflectivity data in a three-dimensional buffer, a display device and a processor that is in data communication with the memory and the display device. The processor receives a two-dimensional shape based on a portion of the data stored in the three-dimensional buffer, then finds a center of the shape. Next the processor finds the furthest away point of the shape in a plurality of regions sharing the center as a common point and generates a polygon based on the furthest away points. The display device displays the generated polygon. The shape is associated with hazardous weather information determined from the radar reflectivity data stored in the three-dimensional buffer. The display device is an aircraft weather radar display.

Abstract: A method detects a target in a sequence of radar images, wherein each image is partitioned into a grid of cells, and wherein each cell has a corresponding position in an image coordinate system associated with a location in a world coordinate system. For each most recent image in a sliding temporal window of images, intensities of each cell are determined, and the subset of the cells having highest intensities is stored as a set of current needles. A set of hypotheses, obtained by using a state transition model and corresponding maximum limits, is determined for the current set of needles and appended to a set of queues. The hypotheses for the previous sets of needles to the corresponding set of queues are updated, and a maximum likelihood in the set of queues are selected to detect the location of targets.

Abstract: Radiolocalization receiver for a satellite radiolocalization system like GPs, Galileo or the like, including a staged correlation and accumulation unit, in which the correlation data is biased in order to be to always non-negative. Thanks to this feature, the accumulated data grow monotonically during the accumulation. Overflow rate of a first correlation stage (100, 150-153) is scaled down respect to the rate of the input data. Thus the higher correlation stages (200, 154-158) can be used in multiplex. The bit-flip rate in memories is very low, with an effective reduction of dynamic power consumption. The logic structure of the accumulator is also simplified by the invention, thus further savings in silicon space and power are possible.