Abstract: A method and radar system for estimating a radar search volume, includes acquiring covariance information relating to a cued direction, the covariance information having an ellipsoidal shape, projecting the ellipsoidal shape covariance information onto a range-traverse plane and onto the range-elevation plane to produce a covariance ellipse on the range-traverse and range-elevation planes; and determining the maximum extents in each of the range-transverse and range-elevation planes wherein the azimuth and elevation extents define the search volume.

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: This disclosure provides a navigation aid device that includes a calculation time setting module for setting two or more calculation points of time for calculating trial information, a ship-concerned information acquisition module for acquiring ship-concerned information including a position of a ship concerned at every predetermined ship-concerned information acquisition time, a ship-concerned trial information calculating module for calculating ship-concerned trial information including the position of the ship concerned at each calculation point of time based on the ship-concerned information acquired at the newest information acquisition time with respect to the calculation point of time.

Abstract: A command and control system for analyzing target track positional information by comparing target location to pregenerated geographic information.

Abstract: A device and method for correcting a position of at least one target point relative to a motor vehicle depending on a movement of the motor vehicle over a given number of cycles; starting from at least one target point, forming a first group with adjacent target points depending on a first given characteristic; verifying if the first group is homogeneous depending on a second given characteristic; and calculating a position of a formed group relative to the motor vehicle over the given number of cycles, a formed group corresponding to a target object.

Abstract: This disclosure provides a navigation assisting device, which includes a TT information acquiring module for acquiring target object data by performing target tracking based on an echo received by a radar antenna, an AIS information acquiring module for acquiring target object data based on a Universal Shipborne Automatic Identification System, a maximum-number-of-output-data determination module for determining a maximum number of output data that is the number of target object data that is outputable while the radar antenna revolves once, a priority determination module for performing a priority determination according to a predetermined rule, for the target object data acquired by the TT information acquiring module and the target object data acquired by the AIS information acquiring module, and an output control module for outputting the target object data fewer than the maximum number of output data according to the priorities while the radar antenna revolves once.

Abstract: Methods and apparatus for a first radar; identifying a blind spot in coverage of the first radar; providing a second radar to illuminate the blind spot, and merging data from the first and second radars using target classification prior to tracking to reduce false targets. In one embodiment, polarimetric data is used to classify targets.

Abstract: A radar system tracks targets, and for each target determines the maximum acceleration of the target which can be tracked. The target acceleration is compared with the maximum acceleration that the radar can maintain in track, and if the decision is that the radar cannot maintain track, the radar data rate is increased, at least for that target. In at least some cases in which the target acceleration is such that the target can be maintained in track, the data rate for that target is decreased.

Abstract: A method for ground surveillance radar performance analysis is disclosed. A vector of point data items indexed by time offset, and comprising a point probability of detection is received. A plurality of initial azimuths of a simulated radar signal of the radar tower is determined based on the radar field-of-regard. A plurality of initial azimuth segment probabilities of detection are calculated for each of the initial azimuths respectively based on the vector of point data items and the initial azimuths, and a segment probability of detection is determined based on the initial azimuth segment probabilities of detection.

Abstract: A system and method are provided for launching and recovering an unmanned, water-born vehicle (UWBV) from a mother ship. The UWBV mimics the behavior of dolphins and is positioned ahead of the ship in preparation for bow riding. The UWBV uses a guidance system to position and keep in the bow wave. A high-frequency (HF) sonar transceiver array aboard the ship computes and sends course corrections to maintain the UWBV within the bow wave. The frequency range of the HF array can be 100 kHz or higher due to the short distance between the ship and the UWBV. Accordingly, the HF array can have a small aperture allowing for accurate bearing resolution. Course corrections can be sent on a near-continuous basis such that changes in thrust and rudder angle can be minimized to allow for accurate control of the UWBV.

Abstract: Described are computer-based methods and apparatuses, including computer program products, for signature matching. In some examples, the method for signature matching includes receiving a first target profile associated with a first data signal, the first data signal associated with a first target object; receiving a second target profile associated with a second data signal, the second data signal associated with the first target object or a second target object; generating a comparison distance utilizing a comparison distance function and based on a comparison of one or more data points associated with the first target profile and one or more data points associated with the second target profile; and determining a signature matching score based on the comparison distance.

Abstract: A radar volume in a cued direction is searched with sequential pencil beams. The cued direction is subject to uncertainty in the form of covariance. The covariance defines an ellipse rotated relative to the azimuth axis. Before determining the extent of the acquisition face, the ellipse is projected onto a viewplane normal to the radar range axis, and rotated so the principal axes are parallel with the traverse and elevation directions. The acquisition face is then found. The number of beams required to scan the search volume is determined. In one embodiment, the search volume is sent to the radar, and the radar rotates the beams to their correct positions. The beams are then scheduled.

Abstract: A system includes a pulsed UHF radar for integrating the signal received over a given integration time. The integration time for the received signal and the size of the distance bin are defined in such a way that, taking into account the range of speeds of the targets of interest, a moving target of interest travels only a distance shorter than the size of the distance bin from one integration period to another. Furthermore, the UHF radar implements a method of forming radar blips from the received signal to form elementary blips from the signals received over the chosen integration time and to store them from one burst to another. The method also confirms that the elementary blips formed probably correspond to targets of interest and then forms, from the confirmed elementary blips, aggregate blips, the attributes of an aggregate blip depending on the attributes of the confirmed elementary blips from which the aggregate blip stems.

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: A method according to an aspect of the disclosure is for partitioning a radar acquisition volume, the method comprising the steps of: determining an allocated time to search an unpartitioned volume; determining a number of beam rows in an unpartitioned acquisition face; determining an average per-row search time for searching the angular region based on the determined allocated time and determined number of beam rows in an unpartitioned acquisition face; determining a number of beam rows in an allotted acquisition period that is searchable based on the average per-row search time; calculating a maximum elevation extent based on the number of beam rows in the allotted acquisition period; and searching an angular extent of the search volume based on the calculated maximum extent.

Abstract: An apparatus and method for combining transponder bandwidths comprises a wide-band virtual transponder for transmitting a single data stream. The wide-band virtual transponder is comprised of a plurality of narrow-band physical transponders. A plurality of elementary streams are statistically multiplexed to create the single data stream, wherein the single data stream is forward error correction encoded and demultiplexed into a plurality of transponder streams for transmission by the plurality of physical transponders. The physical transponders each use a different portion of a signal spectrum, wherein the different portion may be guard bands or a combination of legacy bands and guard bands. Upon receipt, the transponder streams are multiplexed to recover the single data stream, wherein the recovered single data stream is forward error correction decoded and statistically demultiplexed to recover the plurality of elementary streams.

Abstract: Systems and methods for detecting objects and weather in space are disclosed. A system for detecting an object in space and space weather includes at least one spacecraft, at least one radiation source, at least one detector, and a controller. The at least one radiation source and the at least one detector are coupled to the at least one spacecraft. The at least one radiation source is configured to transmit a signal. The at least one detector is configured to detect the signal. The signal may be reflected from an object in space. The controller is coupled to the spacecraft and is in communication with the plurality of detectors. The controller is programmed to calculate either a relative position of the object based or a plasma parameter in a region traversed by the signal based on the detected signal.

Abstract: Radar beams for searching a volume are selected by determining the central angle and azimuth and elevation extents to define an acquisition face. The number of beams NMBA required to cover the acquisition face is determined by N MBA = ( 2 ? n + 1 ) ? ( m + 1 2 ) + ( - 1 ) n + m 2 ( 2 ) The number of beams NMBA is multiplied by the dwell per beam to determine the total search time, which is compared with a maximum time; (a) if the total search time is greater than the permissible time, the acquisition face is partitioned, and (b) if the total search time is less, the acquisition face information is applied to a radar processor for filling the unextended acquisition face with the number NMBA of beams in a particular pattern.

Abstract: In certain embodiments, a method includes receiving first track information comprising data for a particular aircraft track. The method further includes receiving a first radar plot comprising first location information corresponding to first aircraft identification information and first location information corresponding to second aircraft identification information. The method further includes associating the first aircraft identification information with the particular aircraft track. The method further includes accessing historical association information comprising a first association history variable corresponding to one or more previous associations between the first aircraft identification information and the particular aircraft track and a second association history variable corresponding to one or more previous associations between the second aircraft identification information and the particular aircraft track.

Abstract: A method for rapid convergence of radar target state includes the steps of using range acceleration to estimate perpendicular velocity and jump-starting a Cartesian state filter with the estimated perpendicular velocity. The improved estimate in the Cartesian state filter allows improved coasting of the range-state.

Abstract: A method, Kinematic Algorithm for Rocket Motor Apperception (KARMA), for processing radar returns for identifying the type of a missile target includes generating tracks representing the missile, and applying the tracks to a set of plural template-based filters, each representing one missile hypothesis, to generate plural sets of missile states, one set for each hypothesis. The missile states are processed to generate kinematic parameter likelihood values (LLHs). The LLH values for each filter hypothesis are normalized and weighted. A weighted maximum likelihood value (WMLH) is calculated for each hypothesis. The correct hypothesis is deemed to be the one having the maximum WMLH, thus identifying the missile type.

Abstract: A High Performance Unattended Ground Sensor (HiPer-UGS) system and methods comprising low-power fully functional and independent radar-nodes that communicate directly with a remote radar information gathering or relay point using a long distance communications transceiver co-located in the radar-node.

Abstract: A radar volume in a cued direction is searched with sequential pencil beams. The allowable scan time is limited. The cued direction and uncertainty identify a search face, and the range gives a search volume. The number of beams required to scan the volume is determined, and compared with the maximum time. If less than the maximum, the scan is initiated. If greater than the maximum time, the scan region about the cued volume is subdivided into smaller portions, each of which is scanned sequentially.

Abstract: A computer-implemented method for probabilistically classifying an occurrence of an event, a change in the state of a target, includes measuring feature data of the target simultaneously processing the measured feature data through first and second filters. The first filter is suited for a situation in which the target is in a first state and generates a first residual and a first residual covariance for the measured feature data. The second filter is suited for a situation in which the target is in a second state and generates a second residual and a second residual covariance for the feature data. By determining a probability of the occurrence of the event and the probability of the non-occurrence of the event and comparing the two probabilities with at least one threshold value the occurrence or non-occurrence of the event is determined.

Abstract: According to a conventional method of correlating beat frequencies in a radar device, a detecting state of a target differs at the time of up-chirping and at that of down-chirping, so that, when the number of peaks of beat frequencies does not match with each other, there occurs a situation in which the beat frequencies cannot be accurately correlated.

Abstract: A computer-implemented method for estimating track error covariance of a sensor track data in a Link 16 tactical data link network from track quality involves receiving at a computer system the sensor track data on a ballistic target including the track quality and by estimating the track maturity, the position and velocity error covariance eigenvalues (?p, ?v), and the position and velocity error covariances (Cp, Cv), the track error covariance of the sensor track data is calculated. The resulting error covariance is provided to the weapons control systems for more accurate engagement of the ballistic targets.

Abstract: A system includes a pulsed UHF radar for integrating the signal received over a given integration time. The integration time for the received signal and the size of the distance bin are defined in such a way that, taking into account the range of speeds of the targets of interest, a moving target of interest travels only a distance shorter than the size of the distance bin from one integration period to another. Furthermore, the UHF radar implements a method of forming radar blips from the received signal to form elementary blips from the signals received over the chosen integration time and to store them from one burst to another. The method also confirms that the elementary blips formed probably correspond to targets of interest and then forms, from the confirmed elementary blips, aggregate blips, the attributes of an aggregate blip depending on the attributes of the confirmed elementary blips from which the aggregate blip stems.

Abstract: A method for calculating a drop track time for a radar system includes receiving characteristics of the radar system as an input, determining in a computer process the characteristics of a target being tracked by the radar system, calculating in a computer process a target track drop time for the target based on the characteristics of the radar system and the target, determining in a computer process whether a value associated with the target being tracked has been updated within the target track drop time, and discontinuing the tracking of the target if a value associated with the target being tracked is not updated within the target track drop time.

Abstract: A method and apparatus for defending against airborne assault ammunition. The assault ammunition is located with at least one position-locating device. The flight path of the assault ammunition is iteratively calculated using the determined ballistic coefficient of the assault ammunition. A firing control solution is determined for firing a fragmentation-type defense ammunition, which is fired with a large-caliber weapon, especially one having a caliber of at least 76 mm. A fuse of the defense ammunition is set after the firing and/or the defense ammunition is remotely detonated, and after the firing the defense ammunition is ignited or remotely ignited at an ignition time point TZ. Alternatively, the ignition of the defense ammunition is initiated by a proximity igniter disposed in the defense ammunition.

Abstract: Pulse echo signals containing false echoes are processed by forming tracks of multiple received echoes and monitoring these tracks by a recursive filter such as a Kalman filter. A track velocity is estimated for each track, and the position of each the next echo on the track is predicted.

Abstract: Using a radar to detect a known target likely to be positioned at approximately a predetermined height close to other targets, these other targets also being positioned at approximately the predetermined height. A first phase of detecting the known target is carried out by performing an azimuth scan. When the known target has been detected at a certain distance Di at a certain azimuth angle ?az, a second detection phase is carried out at said azimuth angle ?az and at an elevation angle ?EL corresponding to that of an object situated at said distance Di at the predetermined height. The target is said to be detected if it is detected at the elevation angle ?EL at a distance D approximately equal to the distance Di.

Abstract: A method of tracking an object including the steps of: collecting N measurements of range Ri and Doppler velocity Di associated with the object from a plurality M of radar sensors Si each measurement being assigned a time stamp ti; time aligning each Range Ri measurement to a common time stamp tN to provide a corresponding time aligned range Pi for each of the N measurements; using each time aligned Range measurement Pi to define a corresponding spherical equation such that N spherical equations are defined; and deriving analytical solutions from three of the N spherical equations to determine the position vector of the object.

Abstract: The radar tracking or pulse refresh rate is calculated for a target. The refresh rate is selected which makes a sum equal to a predetermined fraction of the radar beamwidth, where the sum is the sum of the bias error and a multiplicative product. The multiplicative product is the product of the random error multiplied by a number associated with the containment probability of the total error.

Abstract: A method and system are provided for merging data from a plurality of multiplexed measurement sources to a decision-maker. The method includes operations for receiving a corresponding plurality of measurements of the data, processing each measurement to respectively obtain local state estimates and local error covariances, determining a corresponding plurality of lag periods, offsetting each of the corresponding event times, supplying to a track fusion center the local state estimates and the local error covariances for summing the pluralities of the local state estimates as a fusion state estimate and the local error covariances as a fusion error covariance. The measurements to be fused are each acquired from its respective source and correspond to an associated sampling period within an acquisition interval. The lag periods represent a wait duration for obtaining the corresponding local state estimates and local error covariances.

Abstract: A data network interconnects ships. At least one ship has sensors which track targets. The data rate over the network is reduced by transmitting hostile target tracks at a greater rate than friendly target tracks, by transmitting hostile target tracks that are closest to friendly assets at a greater rate than hostile tracks at greater distances from friendly assets, andor by predicting the location of a target from old track information previously transmitted over the network, and if the predicted location matches the actual sensed location, transmitting only a track update message, and if the predicted location does not match the actual location, transmitting a complete track update.

Abstract: According to one embodiment, a radar tracking system includes a radar coupled to a radar processing system. Radar processing system receives images from the radar and that are each obtained at a differing angular orientation of the radar to a target. Radar processing system dithers each image along its azimuthal extent and then combines the dithered images to form an enhanced image of the target.

Abstract: The present invention relates to tracking waveforms in radar which minimizes the dwell time and energy in a tracking waveform while maintaining a specified track positional accuracy and consequently velocity accuracy. The present invention provides a method and apparatus for selecting a tracking waveform in a radar apparatus comprising determining a target range rate; determining a signal strength; determining the radiated frequency of the subsequent transmitted tracking waveform; and modifying the energy and pulse repetition frequency used on subsequent tracking waveforms on the basis of the determined target range rate, signal strength and next transmitted tracking waveform frequency.

Abstract: Method, tracking system, and intercept missile for tracking highly maneuverable target objects. The method includes estimating the motion of the at least one target object via a mathematical method that includes a filter method relating to a model assumption for estimating at least one of the motion and an orientation of the target object. The filter method includes a semi-martingale algorithm for estimating motion.

Abstract: A method and apparatus determines the shape of an orbiting or airborne object. A radar determines the general location and a telescope is directed toward the object to form an image of background stars, which will be occluded by the object. The image is compared with a memorized star map, to identify the region of the image in the map. Stars visible in the map which are not visible in the image are listed. The invisible stars are paired with next adjacent visible stars to form star pairs. The midpoints are identified of lines extending between star pairs. Segment lines are drawn between a midpoint and the next closest midpoint. The segment lines define an outline of the object.

Abstract: The vessel monitoring system has, in a trial navigation by provisionally setting a value of the speed of the own vessel arbitrarily, a display unit immediately display an Obstacle Zone by Targets (OZT) corresponding to the speed of the own vessel. The vessel monitoring system includes a calculator for calculating an Obstacle Zone by Targets, a display unit for displaying the Obstacle Zone by Targets obtained by the calculation by the calculator, and an integrated controller for processing trial navigation that integrally controls mutually cooperated processing of calculation by the calculator and display by the display unit, in a trial navigation by provisionally setting a value of the speed of the own vessel arbitrarily, so that the calculator calculates an Obstacle Zone by Targets corresponding to the arbitrarily and provisionally set value of the speed of the own vessel, and the display unit displays the result of the calculation.

Abstract: An interferometric switched beam radar apparatus and method are disclosed. In one embodiment, a selected antenna of a planar array of beam forming antennas is activated with a substantially continuous frequency modulated transmit signal and a return signal is received from at least two return antennas that have a known offset distance relative to each other. Phase information is extracted from each return signal and used to present information regarding an operating environment to a user. Each beam forming antenna within the array may correspond to a particular viewing angle within the operating environment.

Abstract: Methods and apparatus for identifying a plurality of contacts from a signal return, defining a zone containing a number of contacts from the plurality of contacts, determining a centroid for the contacts in the zone, and tracking the contacts in the zone as a single contact based on the centroid.

Abstract: The invention, called “ORSE Track Fusion”, combines sensor tracks from dispersed sites, when limited communication bandwidth does not permit sharing of individual measurements. Since estimation errors due to maneuver biases are not independent for each sensor, optimal fusion of tracks produced by Kalman filters requires transmission of all the filter gain matrices used to update each sensor track prior to the fusion time. For this reason, prior art has resorted to suboptimal designs. ORSE Track Fusion according to aspects of the invention overcomes this disadvantage by propagating, transmitting, and fusing separately calculated covariance matrices for random and bias estimation errors. Furthermore, with ORSE, each sensor can have its own criteria in forming its track, and track fusion can be performed with different criteria at each processing site. Thus, ORSE Track Fusion has the unique flexibility to optimize track fusion simultaneously for multiple criteria to serve multiple users.

Abstract: A system and method for warning a helicopter of an approaching bullet using existing sensor systems is disclosed. The disclosed method including the steps of: detecting and providing bearing information for detected small arms weapon firing locations near the helicopter, determining a detection area and detection time window for the fired bullet, determining the antennas of the RF transmitting and RF receiving systems covering the bearing of the detected weapon firing; determining a timing sequence and allocating time segments for transmitting and receiving RF signals during the detection time window, commanding the RF emitting system to emit and the RF receiving system to receive RF signals during their allocated time segments, processing RF signals received and determining whether reflected RF signal pulses from the emitted RF signal pulses are present, and outputting a warning where reflected RF signal pulses are detected.

Abstract: Various embodiments are described herein for a track quality based multi-target tracker and an associated method. The method includes associating a measurement with a track, generating measurement association statistics for the track, generating and updating a track quality value for a track based on a measurement-to-track association likelihood, and updating track lists based on the track quality value and the measurement association statistics of the tracks in these lists. The tracker includes structure for carrying out this method.

Abstract: A target tracking method uses sensor(s) producing target signals subject to positional and/or angular bias, which are updated with sensor bias estimates to produce updated target-representative signals. Time propagation produces time-updated target states and sensor positional and angular biases. The Jacobian of the state dynamics of a target model produces the state transition matrix for extended Kalman filtering. Target state vector and bias covariances of the sensor are time propagated. The Kalman measurement residual is computed to produce state corrections, which are added to the time updated filter states to thereby produce (i) target state updates and (ii) sensor positional and angular bias updates.

Abstract: A method for determining or compensating for the positional errors of a sensor tracking a target comprises the steps of operating the sensor to generate sensed information relating to the target and adding any sensor positional bias update information to produce updated sensed information. The target state is propagated to produce time updated state estimates. The Jacobian of the state dynamics and the state transition matrix for the extended Kalman filter algorithm are computed. The covariance of a state vector is time propagated using the state transition matrix.

Abstract: A method of tracking a target is applied to a decentralised network (100) comprising a plurality of sensing nodes (110, 120, 130, 140, 150, 160, 170) operable to make observations of the target. The method comprises the steps of: each node (110, 120, 130, 140, 150, 160, 170) performing a multiple models tracking algorithm, thereby updating track information stored at each said node; each node (110, 120, 130, 140, 150, 160, 170) communicating updated track information to selected other nodes in the network (100); and each node (110, 120, 130, 140, 150, 160, 170), in response to receiving track information from another node, conservatively fusing the receiving track information with local track information. In one embodiment, the multiple models tracking algorithm is an interacting multiple models tracking algorithm.

Abstract: Moving objects are detected with a radar by collecting samples of a received signal over an integration period. The terms of a match function contain a product of a sample of said received signal and a delayed-in-time, Doppler-shifted replica of a transmission and depend on parameters that describe an object that caused a reflection of the transmission. The most probable values of the parameters are found by maximizing the match function through Fourier transforming a vector consisting of terms of the match function. Those of said products that contain a non-zero contribution of said delayed-in-time, Doppler-shifted replica of a transmission are actually computed while the others of said products are zero Only non-zero blocks of the products count as final terms to the vector to be Fourier transformed that have nonzero value while intermittent blocks that have zero value are left out.

Abstract: This invention relates to a target detection device and its detection method, comprising: a transmitting unit for transmitting a detecting pulse to detect target which then reflects the detecting pulse to generate a reflected pulse; a plurality of measuring units, located at different positions respectively which receive said reflected pulse and generates measured values of distance and measured values of velocity according to the reflected pulse received; a plurality of two-stage linear Kalman filters, corresponding to said plural measuring units respectively, each of said plural two-stage linear Kalman filters proceeds an operation according to the measured values produced by corresponding measuring unit so as to generate respectively the estimation values of distance, velocity and acceleration; an arithmetic unit connecting to said plural two-stage linear Kalman filters, which proceeds a triangulation operation according to said estimation values so as to generate distance component values, velocity compon