Abstract: A radio frequency (RF) phased array transmitter system comprises a phased array for generating an RF signal. The phased array comprises conductive patches formed in an array, separation gaps, and active sources. Each of the separation gaps is formed between two adjacent ones of the conductive patches, and each of the active sources is formed across its associated one of the separation gaps. The system further comprises an optical source for generating an optical signal and an RF source for generating an RF signal. In addition, the system comprises an optical modulator coupled to the optical source and the RF source. The optical modulator receives an optical signal and an RF signal, and produces an RF modulated optical signal based on the received optical signal and the received RF signal.

Abstract: A radar apparatus includes a transmitting antenna and a receiving antenna that has a plurality of antenna elements, and switches the plurality of antenna elements in synchronization with a modulation period to acquire receiving signals. At this time, the antenna elements are switched in accordance with a combination of a first sub-phase and a second sub-phase in which the antenna elements are sequentially switched in opposite directions to thereby acquire the receiving signals. The radar apparatus calculates an azimuth sine value sin ?1 from the acquired receiving signals of the first sub-phase and calculates an azimuth sine value sin ?2 from the receiving signals of the second sub-phase. Next, the radar apparatus calculates an actual azimuth ? through an averaging process of these azimuth sine values sin ?1 and sin ?2.

Abstract: An antenna is provided, in combination with an associated switch array, the antenna comprising a number of antenna elements mounted above a ground plane for providing coverage over a predetermined range of angles in azimuth using a number of beams. Each of the antenna elements is connected to a switch in the switch array and the switch array is operable to connect selected pairs of the antenna elements to a signal path to thereby generate each of the different beams, at the same time connecting unselected antenna elements to ground.

Abstract: The invention relates to a method for beam formation by calculation. For each defective active module of rank ip, the missing samples of the microwave signal a(îp) are calculated by one or more non-adaptive interpolations using the samples coming from the active modules in nominal operating mode situated in the neighborhood of the defective active modules, the beam being formed as if the interpolated samples a(îp) were the real measurements. In particular, the invention is applicable to the compensation for the effects of failures of one or more active modules distributed over an antenna of a radar with electronic scanning. The method according to the invention can notably be implemented within an airborne weather radar.

Abstract: One embodiment relates to a transceiver. The transceiver includes first and second phase-locked loops. The first phase-locked loop is adapted to receive a reference signal and output a transmission signal based on the reference signal. The second phase-locked loop is adapted to receive the reference signal and output a local oscillator (LO) signal based on the reference signal. The frequency of the LO signal is shifted relative to the frequency of the transmission signal. Other methods and systems are also disclosed.

Abstract: The automatic vehicle braking device is equipped with a braking force control processing portion which, based on the judgment result of a collision judgment processing portion and the judgment result of a steering avoidance judgment processing portion, imparts a turning property in a direction of head-on collision to the vehicle when the lateral position of the obstacle with respect to a travel route curve is large in a condition in which the driver is unconscious of a high possibility of collision between the vehicle and the obstacle and has taken no steering avoidance action yet. As a result, it is possible to reduce the speed of the vehicle and, at the same time, mitigate the damage suffered by the vehicle occupants at the time of collision.

Abstract: A synthetic aperture radar to provide high resolution in the azimuth direction under the predetermined conditions of wide observation swathwidth in the range direction, stripmap observation and free PRF (Pulse Repetition Frequency) comprises a transmission antenna 102 for a single system and receiving antennae 104a, 104b for two systems. The beam width in the azimuth direction of a transmission beam 103 from the transmission antenna 102 is set equal to twice as wide as the beam width of each of the receiving antennae 104a, 104b. Moreover, a receiving antenna beam 105a is directed to the moving direction, while the other receiving antenna beam 105b is directed to opposite to the moving direction. The transmission antenna 102 and the receiving antennae 104a, 104b for two systems are used in common by dividing a single array antenna in the elevation direction to configure the receiving antennae 104a, 104b.

Abstract: A broadcast receiver for receiving airwaves by a directional switching antenna capable of switching directivity in a plurality of directions, includes a control unit for performing signal return processing for making a return to a normal reception state when it becomes impossible to receive the airwaves by the antenna. The signal return processing includes a plurality of signal return processings of different kinds. When impossibility of reception occurs, the control unit selects optimum signal return processing from among the plurality of signal return processings according to predetermined conditions and executes the selected signal return processing.

Abstract: An apparatus and method for transmitting/receiving a signal in a communication system with a plurality of antennas are provided. Received modulation symbols of channel coded transmission information data are generated using a space-time mapping scheme and processed to RF symbols. The RF symbols are transmitted through antennas among the plurality of antennas.

Abstract: A method for determining an adjusted position of a component of an aerial vehicle in response to a situational parameter is provided. The system includes a component mounted on an aerial vehicle, a control system operably coupled to the component, and a processor operably coupled to the control system. The control system adjusts a position of the component based on commands received from the processor. The processor receives positional data and a situational datum relating to the vehicle. The positional data is determined as a function of a situational parameter of the vehicle and is stored in a memory accessible by the processor. The processor determines an adjustment to the position of the component using the situational datum and the positional data and sends the determined adjustment to the control system.

Abstract: An RFDE system includes an RFDE transmitter and at least one RFDE antenna. The RFDE transmitter and antenna direct high power electromagnetic energy towards a target sufficient to cause high energy damage or disruption of the target. The RFDE system further includes a targeting system for locating the target. The targeting system includes a radar transmitter and at least one radar antenna for transmitting and receiving electromagnetic energy to locate the target. The RFDE system also includes an antenna pointing system for aiming the at least one RFDE antenna at the target based on the location of the target as ascertained by the targeting system. Moreover, at least a portion of the radar transmitter or the at least one radar antenna is integrated within at least a portion of the RFDE transmitter or the at least one RFDE antenna.

Abstract: A broadcast receiver includes a smart antenna, a tuner for extracting a signal of a predetermined channel from airwaves received by the smart antenna, a signal processing unit for processing the signal extracted by this tuner, and a control unit for controlling the smart antenna. The control unit detects a receivable direction by performing automatic scanning for each of the channels with respect to each of the directions of the smart antenna, and when the receivable direction is first detected during execution of automatic scanning for a certain channel, the automatic scanning is stopped at a point in time of the detection and transition to automatic scanning for the next channel is made.

Abstract: A method of detecting weather using a weather radar onboard an aircraft. A range is selected at which weather is to be detected. A tilt angle of the weather radar is changed to detect weather below an altitude of the aircraft at a selected range when the selected range includes a maritime environment.

Abstract: A method of determining a radar receiver path, comprising the steps of: obtaining a transmitter position; obtaining a target position and velocity; obtaining a radar receiver position and velocity; determining a transmitter aspect angle gradient, a transmitter aspect angle time derivative and a transmitter co-state vector time derivative; determining a target aspect angle gradient, a target aspect angle time derivative and a target co-state vector time derivative; generating a radar platform heading variable, and a group of differential variables over a defined time span; inputting the group of differential variables into a differential equation solver; receiving a group of possible headings for the radar receiver path; and finding an optimum radar receiver path from the group of possible headings.

Abstract: A system and method for mapping a target scene by means of scanning radar utilizing the Doppler effect that arises in the event of movement between radar and target scene, where the movement of a platform upon which the radar's antenna is mounted is calculated utilizing navigation data obtained for the platform. The system and method can generate high-resolution radar images in an almost forward-looking application. This is achieved by introducing an approach compensation (7), in which the signal quantity received by the radar which is related to transmitted pulses is transformed pulse by pulse to a corresponding movement-corrected signal quantity by displacement in time and phase, dependent upon the platform's movement along an imaginary platform movement directed in such a way that the antenna's momentary direction is essentially 90° to the direction of the movement of the imaginary platform.

Abstract: A wireless communication system includes a transmitter comprising a serial-to-parallel converter for converting serial data bits to a parallel bit stream, a signal mapper coupled to the serial-to-parallel converter and an antenna selector coupled to the serial-to-parallel converter. The signal mapper receives as input a first group of bits from the parallel bit stream, and maps the first group of bits to a channel symbol. The antenna selector receives as input a second group of bits from the parallel bit stream. A transmit antenna array is coupled to the antenna selector and to the signal mapper. The transmit antenna array generates a plurality of transmit antenna patterns with one of the transmit antenna patterns being selected for transmitting the channel symbol based upon the second group of bits from the antenna selector.

Abstract: According to typical practice of an inventive radar system, a switching device is capable of activating a receiver array one at a time so that when a receiver is activated the remaining receivers are inactivated. A switch control circuit is pre-programmed with control logic that is based on the counting of radio pulses that are emitted by a signal generator (for transmission by a transmitter). The control logic dictates, via the switching device, the rapid sequential cycling through of the arrayed receivers so that each receiver is activated for the same prescribed period of time, which corresponds to a pre-programmed number N of emitted radio pulses wherein N=[the number of frequencies in the wave table]×[the number of pulse integrations in the wave table]×[1 polarization or 2 polarizations]. Radio pulse input from the receivers is interleaved in a manner associable with individual receivers.

Abstract: The multi-target tracking and discrimination system (MOST) fuses with and augments existing BMDS sensor systems. Integrated devices include early warning radars, X-band radars, Lidar, DSP, and MOST which coordinates all the data received from all sources through a command center and deploys the GBI for successful interception of an object detected anywhere in space, for example, warheads. The MOST system integrates the optics for rapid detection and with the optical sensor array delivers high-speed, high accuracy positional information to radar systems and also identifies decoys. MOST incorporates space situational awareness, aero-optics, adaptive optics, and Lidar technologies. The components include telescopes or other optical systems, focal plane arrays including high-speed wavefront sensors or other focal plane detector arrays, wavefront sensor technology developed to mitigate aero-optic effects, distributed network of optical sensors, high-accuracy positional metrics, data fusion, and tracking mounts.

Abstract: A hostile intention assessment system and method wherein a tracking sensor subsystem (e.g., radar) tracks targets relative to a critical asset. Determinations are made to assess if a first target is approaching a second target, and to assess if the second target is approaching the critical asset. If the first target is approaching the second target to hide in the radar shadow thereof and the second target is approaching sufficiently close to the critical asset, an alert is generated.

Abstract: A weight calculation method begins by storing a target reflection signal of a radar pulse received via an antenna in cells corresponding to positions along with a reception timing for a plurality of processing range cells having lengths equivalent to prescribed ranges on a time axis. The method continues by calculating weights by stage for the phase and amplitude of the target reflection signal to form a reception composite beam so that arrival directions of spurious elements become zero to an arrival direction of the target reflection signal by using values stored in the plurality of processing cells. The calculating of the weights monitors changes of specific variables indicating correlation values among stages in the plurality of processing stages to stop a shift to the next processing stage at the time when the variables exceed a reference value.

Abstract: A monitoring apparatus of the present application includes: a transmission antenna section that transmits a radio wave of single beam having a wide angle or alternatively a radio wave having a narrower (angular) range in a plurality of beam directions. A receiving antenna section receives the radio wave transmitted by the transmission antenna section and then reflected by a target. A beam switching instrument performs a switching operation such that power is fed to either a first power feed section or a second power feed section, which thereby controls the beam directions of the radio waves to monitor a specified area.

Abstract: A radar apparatus is provided which includes a plurality of antennas arranged at unequally spaced intervals in a single row, the plurality of antennas configured to transmit a radio wave as transmitting antennas during continued multiple periods, and receive a reflected radio wave as receiving antennas during the continued multiple periods. A plurality of transceivers are included for transmitting a radio wave from the transmitting antennas and receiving received signals from the receiving antennas, said received signals representing the reflected wave received at the receiving antennas. A signal processing unit is included for selecting a transceiver which transmits a radio wave during each of the continue multiple periods, selecting transceivers which receive the received signals from the receiving antennas during each of the continued multiple periods, and perform digital beam forming with a first receiving signal channel group and a second receiving signal channel group.

Abstract: A method of detecting weather on an aircraft uses a weather radar system. The method adapts the weather radar system in accordance with a seasonal parameter, a time-of-day parameter, or a location parameter. The method includes determining the particular parameter and automatically adjusting the weather radar system to display the weather in response to the parameter. The system can be implemented in hardware or software and advantageously can more precisely predict and identify weather and/or weather hazards.

Abstract: The present invention relates to a target tracking method of radar with frequency modulated continuous wave, which transmits a transmitted signal to receive a return wave of the transmitted signal that is used for detecting the target and obtaining the relative distance between the target and the radar. The target tracking method includes transmitting a frequency modulated continuous wave and receiving the reflected wave; getting a reflected wave corresponding to the target by detecting the reflected wave; getting a range gate error by seeking the plurality of the range gates corresponding to the reflected wave; and getting a position and a speed of the target at next time by knowing the position of the target at present time basis of the range gate error. Hence, the relative distance between the radar and the target is got.

Abstract: A radar system including a base unit and a radar sensor. The sensor steers a beam in a scanning or tracking manner in both azimuth and elevation. Steering control in azimuth and elevation may be achieved based on configuration settings in the radar sensor processor. The pan-tilt setting may be configured remotely at the base unit. The sensor may include a camera to take panoramic images of the terrain surrounding the sensor, as well as objects-of-interest detected by the system. The sensor is able to transmit radar return information and camera images to the base unit. The base unit is able to display panoramic images and superimpose graphics illustrating a scan profile of the sensor in relationship to the surroundings. The beam steering profile can be controlled by graphically manipulating the profile on the display. This allows configuration of the scanning or tracking profile based on the sensor surroundings.

Abstract: An electric wave transmitting/receiving module includes: a waveguide including a conductive member and an opening facing a transmitting side and/or a receiving side; a dielectric substrate disposed on a side opposite to the opening of the waveguide; and transmitting/receiving means. The transmitting/receiving means includes a core line, a transmitting/receiving element, and a wire. The core line and the transmitting/receiving element are horizontally disposed on the dielectric substrate. The core line transmits the transmitting electric wave and/or receives the receiving electric wave. The transmitting/receiving element outputs a transmitting/receiving signal corresponding to the transmitting electric wave and/or the receiving electric wave. The wire sends the transmitting/receiving signal from the transmitting/receiving element to an external circuit.

Abstract: A weather radar system includes processing electronics. The processing electronics sense weather and determine significant weather based upon the altitude of the weather. The altitude of the weather can be compared to a flight path to determine its significance. A display can provide visual indicia of the significant weather in response to the processing electronics.

Abstract: A controlling device for a satellite antenna is provided. The controlling device includes a first signal generating device generating an inertial compensating signal having a compensating direction; a second signal generating device assembling a received signal from a satellite and generating an orientation with a strongest satellite signal in responding to a signal received from a satellite; a first driving device receiving the inertial compensating signal and driving the satellite antenna toward the compensating direction in a first speed; and a second driving device electrically connected to the second signal generating device and driving the satellite antenna toward the orientation in a second speed.

Abstract: The present invention is directed towards a ballistic missile detection and defense system. The system of the present invention comprises a ship based interceptor or antiballistic missile, a missile launch detection and tracking system, and a signal processing system capable of receiving said tracking signal calculating an intercept trajectory for an antiballistic missile to intercept a ballistic missile, and further capable of outputting an intercept trajectory program to an antiballistic missile.

Abstract: An airborne radio frequency (RF) antenna terminal system includes a two-axis gimbals control system and a phased array antenna. The phased array antenna electronically steers the receive and transmit beams using phase shifters. The electronically steered beams provide a virtual third-axis for the two-axis gimbals control system. The combination of the electronically steered beams and the two-axis gimbaled system provides accurate beam steering for the keyhole region of the two-axis gimbals control system so that the RF communication link is prevented from being lost in the keyhole region.

Abstract: The present invention relates to a radar apparatus that forms multiple digital beams based on reflected waves of a transmitted radio wave. A transmit signal is transmitted in a predetermined cycle from one of transmitting/receiving antennas A1 to A4 arrayed in a row. The antennas A1 to A4, each switched between transmission and reception, are arranged such that the ratio of the spacing between one pair of adjacent antennas to the spacing between the other pair of adjacent antennas is 1:2. The reflected waves are received by the respective antennas, and DBF is performed based on the resulting received signals. Eleven-channel DBF is achieved using the four antennas with a space equivalent to six antennas. By achieving multiple channels with a minimum number of antennas, the size and cost of the apparatus can be reduced while also reducing the processing time and thus enhancing the performance.

Abstract: A path in three-dimensions for an object in flight is determined according to a radar signal reflected by the object. The radar signal is transmitted at an offset angle from horizontal sufficient to capture the object within the transmitted radar signal. The transmitted radar signal is reflected by the object to form a reflected radar signal containing an indication of a position of the object. The reflected radar signal is received and used to determine two-dimensional position information for the object by detection of the indication of the position of the object in the received radar signal. Position information is derived in three-dimensions from the position information in two-dimensions. The path information representative of the path for the object is obtained from the position information in three-dimensions based on an optimization of a curvature of said path information.

Abstract: A method is described for detecting an object with target radar. After the first detection of an object, the antenna is tilted. The original direction towards the object is restored by electronically steering the emitted beam. The beamsteering is obtained by changing the frequency of the emitted signal. Thus, the object may be detected several times on different frequencies. The method is particularly applicable in search and track radars.

Abstract: A method is disclosed for evaluating the terrain surrounding a radar site. The method comprises to calculate the radar horizon around a radar site from stored terrain elevation information. The information obtained can be used for controlling the scanning profile of the radar, by letting the radar scan above the calculated horizon, and thus avoiding transmitting into the terrain.

Abstract: An antenna steering algorithm for a smart antenna uses signal quality metrics and link quality metrics for selecting a preferred antenna beam. The link quality metrics supplement the signal quality metrics for improving the antenna steering decision. The link quality metrics are based on information available from existing counters operating in the media access control (MAC) layer. Separate estimates of the frame error rates in the receive links and in the transmit links are obtained. One estimate is the downlink quality metric (DLQM) and another estimate is the uplink quality metric (ULQM). Alternative link quality metrics are based on throughput and data rates of the exchanged data.

Abstract: An antenna system electronically searches for a satellite signal by beginning at the current pointing angle of an antenna. The antenna system sweeps a tuner frequency of the receiver by electronically commanding the receiver to tune to different transponder frequencies. By scanning through transponder frequencies, the antenna system can locate a satellite signal without mechanical movement. As a result, the satellite signal can be acquired more quickly than in some conventional systems.

Abstract: A technique for boresighting an antenna mounted on a moving platform is described. The technique uses a concurrently moving calibration target. Target navigation data and platform navigation data are used to compensate for movement of the target and the platform. The antenna pointing direction is biased in a direction which provides a best signal quality, and the bias used to determine antenna boresight calibration factors. The boresight correction factors can be used for open loop pointing.

Abstract: Methods and apparatus are provided for operating a radar system to provide a thunderstorm image to a pilot. The method comprises using one or more radar scans depending upon the aircraft altitude, a single upward tilted scan at or below a datum level of about 15,000±3000 feet wherein a clutter free storm image may be obtained and two scans above the datum level; a first upward tilting scan to determine, clutter free, a storm head perimeter and a second lower tilting scan for the storm body with ground clutter. The perimeter is used to discard return echoes from the second scan that lie outside the perimeter or an expansion thereof and retain those lying on or within the perimeter. The result is presented to the pilot. Optionally, the thunderstorm image is graded from center to edge so as to indicate weaker echo intensity near the edge.

Abstract: A method and an antenna arrangement are disclosed for reducing the antenna radar cross section for an externally illuminating radar source. A radar pulse is transmitted with the antenna arrangement fully matched to achieve a lowest possible power loss of the pulse. At all other times the antenna will be poorly matched and thereby will act as a low radar cross section. The reduced radar cross section leads to an antenna gain reduction, which most often can be accepted since competing noise is reduced as much as the useful signal. It is further suggested that the range gate of the receiver and the transmitter pulse control the antenna. Thus, the antenna is “fully opened” during the transmitting pulse and may be partly or “trade-off” matched during range gate reception. In the interval of not transmitting or receiving, the antenna will present a low radar cross section.

Abstract: An imaging apparatus has transmitter illuminating a selected surface with a radar beam footprint, and processor for profiling/processing the radar returns so as to derive attitude information in real time about a number of predefined axes associated with the radar which depends upon the relative dispositions of the radar, the selected surface and upon the radar beam footprint characteristics. A plurality of transmit beams image the surface and the processing arrangement has the capability of determining roll, pitch and/or yaw pointing data associated with the radar, such pointing data being determined by derivation of the attitude information and by selective input of terrain elevation data so as to take account of variations in the radar viewing geometry with terrain elevation. This provides a low cost advantage over known radar designs, and retains utility for many applications, for example spaceborne and airborne applications.

Abstract: A target tracking arrangement predicts the state of a target. The predictor may be a Kalman filter. In the presence of a target which is maneuvering, the prediction may be in error. A maneuver detector is coupled to receive residuals representing the difference between the predictions and the target state. The maneuver detector is matched to the predictor or Kalman filter to thereby tend to reduce the undesirable effects of system noise. The matching may be of the frequency response.

Abstract: Provided is an antenna control apparatus for controlling an antenna mounted on a stratospheric platform of the stratospheric communication system. The apparatus includes a plurality of location signal receivers, each receiver being positioned at each of predefined different points of the stratospheric platform and receiving a location signal for the stratospheric platform, a calculating circuit for calculating an adjustable displacement for the antenna, and an antenna driver for adjusting a direction of the antenna. The calculating circuit calculates a location and attitude of the stratospheric platform based on the location signals, and then computes the adjustable displacement using the location and attitude information. This invention can reduce power consumption in the stratospheric platform and recovery time of directional point of the beam.

Abstract: An inspection system uses microwave radiation to capture a microwave image of a transportable item. The system includes a transmit scanning panel including a transmit array of transmit antenna elements, each being programmable with a respective phase delay to direct a transmit beam of microwave radiation toward a target of the transportable item for transmission of the microwave radiation through the target. The system further includes a receive scanning panel including a receive array of receive antenna elements, each being programmable with a respective phase delay to receive a receive beam of microwave radiation from the target. A processor measures the amplitude and phase of the microwave radiation in the receive beam to determine a relative value of a pixel within the microwave image of the transportable item based on a reference value of the pixel.

Abstract: An automotive radar which can process signals at high speed to detect a target in a wide angle range is provided. The automotive radar comprises a transmitting antenna which emits an electromagnetic wave, two receiving antennas which receive the electromagnetic wave reflected by a target, an antenna plate on which the transmitting antenna and two receiving antennas are arranged. It also includes a drive which rotates the antenna plate in an azimuth direction, which corresponds to the direction of arrangement of the two receiving antennas, to scan a detection angle formed by the two receiving antennas. The drive has rest time between scans to stop rotation. The automotive radar also includes a signal processor which detects the azimuth angle of the target with respect to a reference direction during the rest time according to received signals from the two receiving antennas and the rotation angle of the antenna plate at rest.

Abstract: A method of adapting weather radar thresholds is disclosed. The method comprises generating a location from a location sensor, retrieving information representative of a weather type from a database, based on the location, and adjusting, automatically, the threshold for a radar display based on the information.

Abstract: An FM-CW radar apparatus capable of detecting a stationary object, in particular, an overbridge, located above the road ahead in a simple manner uses a traveling wave antenna as a transmitting antenna, and includes a means for varying, in upward and downward directions the projection angle of a combined beam pattern of a transmitted wave radiated from the traveling wave antenna, and an overbridge is detected by varying the projection angle of the combined beam pattern in the upward direction using the varying means. Further, a phase shifter for varying the projection angle of the beam pattern in upward/downward directions by controlling the phase of the radio wave to be transmitted or received is provided on either a transmitting antenna or a receiving antenna or on a transmitting/receiving antenna, and an overbridge is detected by controlling the phase shifter and varying the projection angle of the beam pattern in the upward direction.

Abstract: Provided is a bistatic and multistatic system for detecting and identifying a target in close proximity to an orbiting satellite. An electromagnetic fence is established to surround the satellite, using a ground-based communication uplink from a gateway antenna. A contact or breach of the electromagnetic fence by the target is detected by the satellite, or at other sensor locations, and an exact position, range and ISAR image of the target is calculated using scattered RF energy from the fence. Identification data is transmitted to satellite system monitors, whereby the data is used to decide on a corrective course of action.

Abstract: An attitude sensing apparatus for determining the attitude of a mobile unit is provided that can reliably estimate an alignment angle between a GPS antenna coordinate system and an IMU coordinate system with good accuracy regardless of the magnitude of the alignment angle. Based on observation of the difference between a GPS angular velocity and an IMU angular velocity, an alignment angle estimating section estimates an alignment angle and sensor errors. An alignment angle adder and a sensor error adder cumulatively add and update the estimated alignment angle and sensor errors, respectively. The estimated alignment angle is fed back to an inertia data converter while the estimated sensor errors are fed back to an inertia data correcting section. The apparatus repeatedly performs estimation until the estimated alignment angle gradually approaches a true alignment angle by successively feeding back estimated values to a flow of alignment angle estimation process.

Abstract: An active protection system comprising an ultrawideband radar for threat detection, an optical tracker for precision threat position measurement, and a high powered laser for threat kill or mitigation. The uwb radar may use a sparse array antenna and may also utilize Doppler radar information. The high powered laser may be of the optically pumped solid state type and in one embodiment may share optics with the optical tracker. In one embodiment, the UWB radar is used to focus the high power laser. Alternative interceptor type kill mechanisms are disclosed. In a further embodiment, the kill mechanism may be directed to the source of the threat.

Abstract: A method and apparatus for estimating elevation angle when using a broad search beam such as a cosecant-squared beam is provided. The range of a target detected during a search with a broad beam covering a broad angular search area is determined. Based on the determined range, consecutive beams are transmitted at increasing search elevation angles in the broad angular search area. Echo signals of the consecutive beams are used to determine an elevation angle estimate for the target.