Abstract: An apparatus and method for protecting against incoming projectiles comprising transmitting two radar waveforms, the first waveform comprising a pulsed continuous wave waveform, and the second waveform comprising a pulsed linear chirp waveform over a bandwidth, and based on returned radar data, causing deployment of a defense mechanism to intercept a detected incoming projectile.

Abstract: An ultra wide band (UWB) millimeter (mm) wave radar system includes a signal source having a control input, a GHz signal output and a frequency controlled output. A control loop is coupled between the GHz signal output and the control input including a frequency divider and a digitally controlled PLL that provides a locked output coupled to the control input of the signal source to provide frequency locked output signals that are discrete frequency swept or hopped. A frequency multiplier is coupled to the frequency controlled output of the signal source for outputting a plurality of mm-wave frequencies. An antenna transmits the mm-wave frequencies to a surface to be interrogated and receives reflected mm-wave signals therefrom. A mixer mixes the reflected mm-wave signals and mm-wave frequencies and processing circuitry determines at least one parameter relating to the surface from the mixing output.

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: In an object verification method for use in radar systems for motor vehicles, the distances and relative velocities of located objects are determined on the basis of received radar echoes. The signature of multiple reflections is searched for in the received radar echoes to verify real objects.

Abstract: An FMCW radar sensor having a plurality of antenna elements and a supply circuit for supplying transmission signals having ramp-shaped modulated frequencies to the antenna elements, including a switchover device for switching over the supply circuit between a near-field mode, in which the transmission signals supplied to the individual antenna elements have a certain frequency offset, and a far-field mode, in which the frequencies of the transmission signals are identical.

Abstract: A movement detection system includes a microwave antenna able to transmit microwave frequency signals into a space. An electronics controller is connected to the microwave antenna, and is configured to continually measure the impedance of the microwave antenna while it transmits microwave frequency signals into the space. An interpretive device is connected to receive impedance measurements from the electronics controller, and is configured to interpret and report changes in the magnitude and phase angles of individual impedance measurements as the passing of things and their direction through the space.

Abstract: An RF signal processing device which includes a countermeasure set connected to the processing device. The RF signal processing device shifts an incoming RF signal by ninety degrees and combines the phase shifted RF signal with RF jamming signals from a jammer. The processing device next transmits the RF signal including the RF jamming signals from the jammer.

Abstract: A radar device has a plurality of receiving antennas which receive, as a reception wave, a radar wave sent in a predetermined reference direction and reflected by a target; a phase difference detection unit which detects a first phase difference of the reception wave received by a first receiving antenna pair that is spaced by a first gap, and a second phase difference of the reception wave received by a second receiving antenna pair that is spaced by a second gap smaller than the first gap; and an angle detection unit which performs a first process of determining, as a detection angle, an angle of the target relative to the reference direction being a mutually coincident angle from among a plurality of first angles corresponding to the first phase difference and a plurality of second angles corresponding to the second phase difference. The radar device allows expanding an angle detection range without reducing the resolution of the angle corresponding to the second phase difference.

Abstract: Method and apparatus for determining the thickness of material layers of a container-held substance comprising a first material disposed in an upper layer and a second material disposed in a lower layer, by transmitting a radio signal through the substance towards a container portion; receiving reflected signals from a surface of the upper layer, a surface of the second layer, and the container portion; varying the frequency of the transmitted signal to determine phase displacement between transmitted and reflected signals; determining optical distances to the surfaces and the container portion, dependent on the phase displacements; determining the thickness of one of said layers dependent on phase displacement through and index of refraction of that layer; and determining the thickness of the other layer dependent on the thickness of said one of said layers.

Abstract: A transmitter system can have a higher power transmitter and a lower power that are configured to transmit a pair of unbalanced radio frequency beams to a target so as to produce a difference frequency in the target. The difference frequency can disrupt operation of a device, such as a weapon. The difference frequency can provide a radar return. The use of a higher power transmitter and a lower power transmitter reduces costs, size, and weight as compared to the use of two higher power transmitters.

Abstract: A method for determining at least one of the distance to and the speed of an object is discussed. The method comprises determining an indication of whether the object is approaching or moving away and generating an interrogation signal comprising a sequence consisting of segments at constant frequency and segments of varying frequency, wherein if the determining step indicates the object is approaching then the varying frequency segments have decreasing frequency and if the determining step indicates that the object is moving away then the varying frequency segments have increasing frequency. The interrogation signal is transmitted and a version of the interrogation signal reflected from the object is detected. At least one of the distance to and speed of the object is then determined using a combination of the interrogation signal and the reflected version of the interrogation signal.

Abstract: Disclosed is a method, means for and computer program for enhancing range and azimuth resolution in a two-dimensional (2D) image generated by a frequency modulated continuous-wave (FMCW) radar for providing enhanced situational awareness in autonomous approach and landing guidance (AALG) system by forming and displaying a two-dimensional (2D) model of landing conditions from received range and azimuth real beam radar (RBR) signals by rendering one or more target locations and amplitudes in both range and azimuth, selecting a region of interest from the displayed 2D model to enhance the one or more target locations in the selected region of interest, selectively applying range and azimuth resolution enhancement using a first and second beamforming approach or applying azimuth only resolution enhancement by using just the second beamforming approach to obtain an one or more accurate target location estimations and combining the enhanced one or more target locations to render an enhanced 2D image.

Abstract: A radar having a high time and high spatial resolution and being capable of performing volume scanning with an inexpensive and simple structure, while enabling reduction is size and weight. A radar (50) is provided with an antenna unit (51) including a radio wave lens antenna device, which has a spherical transmission radio wave lens (2), a spherical reception radio wave lens (3), a primary radiator (4) arranged at a focal point of the radio wave lens (2), and a primary radiator (5) arranged at a focal point of the radio wave lens (3). The primary radiators (4, 5) pivot in an elevation direction about an axis connecting center points of the radio wave lenses (2, 3) and pivot in an azimuthal direction about an axis orthogonal to the axis connecting the center points of the radio wave lenses (2, 3).

Abstract: A method for lessening disturbances of a measurement signal in a radar unit for distance measurement by means of frequency-modulated radar in continuous wave operation. The method comprises steps of: registering, in a reference measurement, a reference signal as a function of time; deriving an error correction signal from the registered reference signal, wherein the error correction signal predominantly comprises spectral components caused or influenced by device-specific defects of the radar unit; registering a measurement signal; and correcting the measurement signal in accordance with the error correction signal by means of digital signal processing.

Abstract: A frequency modulated continuous wave (FMCW) radar is described. The radar includes a first discriminator for receiving a portion of the swept frequency signal generated by a frequency sweep generator and for producing a reference difference-frequency signal of frequency equal to the difference between the frequency of the swept frequency signal and the frequency of a time displaced swept frequency signal derived from the swept frequency signal. An analogue-to-digital converter is provided for sampling the target difference-frequency signal at a rate derived from the frequency of the reference difference-frequency signal. A processor (88) for determining frequency components of the digitized target difference-frequency signal is arranged to determine for at least one frequency component of the digitized target difference-frequency signal any phase difference between frequency sweeps of said swept frequency signal. The radar may be used for detecting foreign object debris (FOD) on runway surfaces and the like.

Abstract: A vehicle system includes a signal processing module and a first antenna that provides a first transmitted signal that has a first phase. A second antenna of the system provides a second transmitted signal that has a second phase that differs from the first phase. At least one receive antenna of the vehicle system receives first and second received signals that correspond to the first and second transmitted signals, respectively. The signal processing module processes the received first and second signals based on the first and second transmitted signals and selectively controls transmissions of the first and second transmitted signals.

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

Abstract: An active YIG oscillator driving device is comprised of: an YIG oscillator including a main coil, an FM coil, a frequency generator operating to generate an output frequency in response to a magnetic field generated from the FM coil; a phase locker setting the output frequency to a target frequency by controlling an amount of current provided into the FM coil and adjusting the output frequency; and a main coil controller regulating the amount of current provided into the main coil, if the output frequency varies out of a controllable range by the FM coil, and adjusting the output frequency. A time for setting the output frequency of the YIG oscillator is shortened to improve the stability of the output frequency thereof against environmental conditions.

Abstract: A radar device includes a transmission antenna and a reception antenna having a plurality of antenna elements. The radar device switches the antenna elements in synchronization with a modulation cycle, thereby obtaining a reception signal. At this time, the radar device obtains the reception signal by switching the antenna elements using a first measurement phase and a second measurement phase having different switching cycles as one set. The radar device calculates an azimuth sine value sin ?1 from the reception signal in the first measurement phase and also calculates an azimuth sinusoidal value sin ?2 from the reception signal in the second measurement phase. Then, the radar device calculates a relative velocity V from the azimuth sine value sin ?1, the azimuth sine value sin ?2, an interval time difference ?t between switching cycles, and an inter-antenna element spacing d.

Abstract: A radar level gauge system for determining a filling level of a product contained in a tank, comprising: a transceiver for generating, transmitting and receiving frequency-modulated electromagnetic signals; a transmitting propagating device electrically connected to the transceiver and arranged to propagate transmitted electromagnetic signals towards a surface of the product contained in the tank; and a receiving propagating device electrically connected to the transceiver and arranged to return echo signals resulting from reflections at impedance transitions encountered by the transmitted electromagnetic signals, including a surface echo signal resulting from reflection at the surface, back to the transceiver.

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: A continuous wave frequency shift-keyed radar apparatus comprising means for changing the frequency of the transmitted continuous wave periodically and in a pseudo-random sequence, means for mixing the received wave with the transmitted wave or a delayed version thereof to produce a beat signal, means for sampling the beat signal, in respect of each period of simultaneous transmission and reception at the same frequency, means for reordering successive segments of the sampled beat signal to put them in sequential frequency order, and means for transforming the reordered segments to provide an output signal in the range domain.

Abstract: A level measuring instrument has a variable transmitting power for measuring a filling level in a tank. The level measuring instrument includes a generator unit generating one of a first oscillator signal and a second oscillator signal. The generator unit generates a transmit signal from one of the first oscillator signal and the second oscillator signal. The level measuring instrument includes further a controller controlling the generator unit. The generator unit generates one of first and second transmitting powers for the transmit signal.

Abstract: Distance measuring apparatus has a rough distance measuring circuit (18) using a time delay circuit and a precise distance measuring circuit (31) for measuring the orientation of the vector of a carrier wave to determine the distance, the sum of which is the final output. The rough distance measuring apparatus (18) has a long measurement span but low precision. The precise distance measuring apparatus (31) has a short measurement span but high precision. The combination provides distance measuring apparatus having a long measurement span and high resolution and capable of implementing precise measurement.

Abstract: A beat signal normalizing section in a correction control section normalizes a group of sampling data of an input beat signal in one processing group. A phase amount measuring section calculates an amount of phase change of each sampling data. A correction control value calculating section compares the actually measured amount of phase change of each sampling data with an ideal amount of phase change of each sampling data and generates correction voltage data such that the actually measured amount of phase change matches with the ideal amount of phase change. Correction control data provided as the correction voltage data at each sampling time is applied to a transmission control section. The transmission control section generates transmission control data based on the correction control data and applies the transmission control data to a VCO through a DAC.

Abstract: Methods and apparatus for determining an altitude with an altimeter is provided. One method includes transmitting a signal having a fixed modulation period towards a ground target and then detecting reflected signals off the ground target. The method then implements a single Fast Fourier Transform (FFT) on the detected signals for each modulation period that computes all possible altitudes in real time. A short history of the real time altitude calculations is collected and then the altitude based on the short history of the real time altitude calculations is determined.

Abstract: Provided is a radar apparatus that detects an object, and includes: an oscillating unit for generating carrier waves; first and second transmission units for spreading the carrier waves, respectively using a first pseudo-random code and a second pseudo-random code different from the first pseudo-random code; a first transmission antenna for transmitting the carrier waves spread by the first transmission unit; a second transmission antenna for transmitting the carrier waves spread by the second transmission unit and have a directional characteristic different from that of the carrier waves transmitted by the first transmission antenna; a reception antenna for receiving reflected waves that are the carrier waves that have been transmitted by the first and second transmission antennas and have been reflected from the object; and a reception unit for despreading the reflected waves, using the first pseudo-random code and despreading the reflected waves, using the second pseudo-random code.

Abstract: A radar system and method for determining the range and, optionally, the azimuth of a target, while maintaining a high transmitting duty factor is provided. A waveform generator is connected to an antenna aperture by a transmit-receive switch, and the waveform is transmitted for more than half of the period of time of the sum of the transmission period and the receiving period. For a frequency-modulated continuous-wave waveform (FMCW), the receiver may be turned on for short intervals at a rate which is at least the Nyquist rate for the signal received from at target. A monopulse or frequency-scanned antenna may be used to determine azimuth as well as range.

Abstract: In a sensor and a radar for measuring the distance and the moving speed of a target by radiating a radio frequency, particularly a millimeter wave, compatibility between cost reduction and high detection performance has been conventionally a significant problem. In the present invention, the frequency of a transmitted signal changes during a fixed time while performing digitally-frequency-modulation on frequency sweeping straight lines extending, with different slopes relative to the time axis, from plural slightly different initial values serving as starting points, the signal is transmitted after being modulated so as to periodically repeat the sweep time serving as a unit, signal components corresponding to the respective sweeping slopes are digitally sampled, in synchronization with the transmitted modulation signal, from a received signal which is reflected and returned from a target, and the received signal is analyzed.

Abstract: The present invention relates to a UWB distance measurement system and method of driving the system. The system includes a reception antenna for receiving a signal, which is output from a transmission unit, is reflected from a target and is incident on the reception antenna, a UWB amplifier for amplifying the received signal and generating a first signal, a reference waveform generator for generating a reference waveform which is a reference for analysis of the first signal, a window function generator for generating at least one window function that is applied to the first signal, a correlator for correlating the first signal with the window function output from the window function generator, and generating a second signal which is a revised frequency response of the first signal, and a delay time detector for detecting a delay time component in the second signal.

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: In a FM-CW or CW radar apparatus, when interference components are contained in channel signals obtained as beat signals from array antenna elements of respective channels, and the interference components result from directly receiving transmitted CW radar waves from an external source, phase shifting is applied to each of the channel signals to shift respective phases of the interference components of the respective channels to a condition corresponding to reception of interference waves from a predetermined direction. The interference components are then eliminated, and reverse phase shifting is applied to restore remaining components of the channel signals to their original phase condition.

Abstract: The invention relates to an FMCW radar system and a method of operating an FMCW radar system to produce a linear frequency ramp. The FMCW radar system includes a VCO, a frequency divider coupled to the VCO output, followed by an A/D converter. A down-converter shifts the digitally converted signal to baseband samples, followed by a low-pass filter coupled to an output thereof. A VCO frequency estimator produces instantaneous VCO frequency estimates from phase differences determined from the filtered baseband samples. A D/A converter coupled to an output of the VCO frequency estimator produces an input signal for the VCO to produce therewith a linear VCO frequency ramp. A ?-? modulator is coupled between the VCO frequency estimator and the input of the D/A converter to produce a dithered VCO control signal, thereby increasing the effective number of bits of the D/A converter.

Abstract: The invention relates to a method for operating a radar system (100) especially of a motor vehicle (200), comprising at least one first sensor module (110a) and at least one additional sensor module (110b). A detection range (A) of the first sensor module (100a) at least partly overlaps a detection range (B) of the additional sensor module (110b) while the first sensor module (100a) receives a transmit signal transmitted by the additional sensor module (110b) in a monitoring mode (305) in order to obtain information about the operating condition of the additional sensor module (110b).

Abstract: A transmit-receive FM-CW radar apparatus according to one mode of the invention comprises: a mixer for downconverting an IF signal; a switch provided on the input side of the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the IF signal in the different modes for supply to said mixer. A transmit-receive FM-CW radar apparatus according to another mode of the invention comprises: a mixer for downconverting an IF signal; a switch for turning on and off a local signal to be supplied to the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the local signal in the different modes for supply to the mixer.

Abstract: A method and device are provided for measuring distance and relative speed of a plurality of objects with the aid of an FMCW radar, transmitted signals being reflected by objects, and the reflected signals being received and mixed with the transmitted signals. A combination of distance and relative speed values is assigned to the mixer output frequencies of each frequency ramp for each object, and the distance and relative speed of a possible object are determined from points of intersection of a plurality of distance and relative speed combinations. The apparent (unreal) objects are eliminated by modifying the frequency slope of at least one frequency ramp according to the random principle in a subsequent measurement cycle.

Abstract: A radar target detection method in which an azimuth at which a target is located is detected on the basis of reception signals obtained through antenna elements of an array antenna by detecting a change in levels of spectrum peaks in an azimuth spectrum of reception signal intensities, calculating a level of correlation between the level change of each spectrum peak and a directivity pattern of the array antenna in an azimuth range corresponding to the spectrum peak, and determining an azimuth corresponding to one of the spectrum peaks having the highest corresponding correlation level to be the azimuth at which the target is located.

Abstract: An electronic scanning radar apparatus has a cutting portion for cutting receiving data which is comprised of N numbers of data for each channel into two more short time data having M (<N) numbers of data in a time direction for each channel, an inverse matrix estimator for computing and estimating an inverse matrix of the time series correlation matrix from the short time data, and a phase information producing portion for computing CAPON phase information out of the estimated inverse matrix of the time series correlation matrix in order to detect a distance, an azimuth and a relative speed of a target on the basis of a computed CAPON phase information.

Abstract: A radar apparatus includes a sending unit for sending a transmission wave, a plurality of receiving parts for receiving a reflected wave from a reflecting object in a parallel manner, beat signal generation parts for acquiring beat signals at the receiving parts, respectively, from the transmission wave and the wave received at the receiving parts, a beat signal processing part for individually processing the beat signals of the receiving parts, a DBF processing part for DBF processing a beat signal processing result, and an object detection part for acquiring information on the reflecting object from frequency components of a DBF processing result or the beat signal processing result. Amounts of phase lag of the receiving parts are set to different values. The beat signal processing part includes a phase correction part that corrects the phase lag amounts corresponding to the individual receiving parts so as to make them equal to one another.

Abstract: A radar system transmits a beam of detection radio waves with a predetermined azimuth width, receives a reflected wave from a target, changes a central azimuth of the beam, and detects the distribution of reception signal strengths at predetermined angular intervals and for each predetermined distance. Then, when the reception signal strength distribution associated with changes in azimuth is expressed in rectangular coordinates, an azimuth corresponding to a vertex of an isosceles triangle that approximates the reception signal strength distribution and has an azimuth width, which is determined by the beam azimuth width, as its base is detected as the central azimuth of the target.

Abstract: There is provided a radar system for detection of one or more objects. The radar system comprises a radar wave transmitter for simultaneously transmitting a CW radar signal and a FM-CW or MF radar signal, and a first radar wave receiver for receiving CW and FM-CW or MF radar signals, reflected from one or more objects present in a detection range of the radar system. The system may further comprise a first CW mixer for mixing CW transmission signals and reflected CW signals received by the first receiver, and a first FM-CW or MF mixer for mixing FM-CW or MF transmission signals and corresponding reflected FM-CW or MF signals received by the first receiver.

Abstract: A multifunction detector for detecting energy reflected from the surface, the detector comprising: a focal plane array in communication with the optical receiving path; and an optical receiving path; a read-only integrated circuit in communication with the optical receiving path, integrated with a focal plane array; and a processor programmed to operate the focal plane array and read-out integrated circuit in a first mode to process signals in a first frequency band, and in a second mode to process signals in a second, wider frequency band.

Abstract: A target detecting apparatus mounted on a vehicle has an electronically agile radar detecting a beat signal indicating a difference in frequency between transmission and reception signals and producing a time series of N reception data from the beat signal, a determining unit determining search areas placed at different ranges of distance from the vehicle while considering a running state of the vehicle and determining a data length for each search area, an extracting unit extracting (N?M+1) time series of short time data, respectively, having the data length corresponding to M reception data from the N reception data for each search area, a producing unit producing phase information from the short time data for each search area, and a detecting unit determining a target distance and a target bearing from the phase information and detecting a target from the target distance and the target bearing.

Abstract: A sampled beat signal RD is split into a plurality of short-time data SD in the time direction, for each of antenna elements. Interference component frequency of an interference wave is detected from a frequency spectrum of the short-time data SD. A digital beam forming process is performed for the interference component frequency of the interference wave to extract a peak of the electrical power of an azimuth direction and estimate an absolute value of an incoming direction of interference components. Based on the absolute value of the incoming direction of the estimated interference components, a filter for suppressing the interference components is operated to suppress the interference components.

Abstract: In fill-level measuring devices that operate according to the FMCW principle, nonlinearity of the sensor signal depending on the time can result in measuring inaccuracies. The fill-level measuring device that operates according to the FMCW principle comprises a correction unit for the mathematical correction of the amplitude values or for calculating points in time of scanning the amplitude values on the basis of a reference correlation determined at the factory. In this way intermediate-frequency values that are identical to those of an ideal sensor can be derived.

Abstract: The present invention is a system and method for detecting devices with receivers, such as explosive devices with receivers used to remotely detonate the explosive devices. The system for detecting devices may include a transmitter which transmits a signal causing saturation of a device whereby harmonic content is emitted by the device. Receipt of an emitted harmonic signal which is coherent to the transmitted signal may indicate the presence of a device. A distance between the system and the detected device may be determined by modulating a frequency of the transmitted signal and measuring the time period between transmission of the signal and receipt of a harmonic signal. Additionally, direction information may be determined which may allow identification of a location of the device based upon the distance information and direction information.

Abstract: A dual mode motion sensor for detecting both motion of a moving target and a range of the moving target. The dual mode motion sensor normally operates in a pulse transmission mode. If motion is detected, the sensor automatically switches to a frequency modulated continuous wave transmission mode. This will allow the sensor to determine the range of the moving target. The sensor includes a microcontroller that compares the determined range of the moving target with a predetermined maximum detection range. If the determined range is outside or exceeds the predetermined maximum detection range the sensor will ignore the motion. If the determined range is within the predetermined maximum detection range, an alarm will be generated.

Abstract: Multiple signal characteristics representing an entire field of view of an FMCW (FM-CW) sensor are evaluated to determine whether the field of view has changed. Signal characteristics representing the field can be compared to representative signal characteristics obtained from previous scans. At least one signal characteristic representing at least a portion of the scene can be evaluated by comparing the signal characteristic to a dynamic threshold. The dynamic threshold can be redefined after each scan from the statistics of the signal characteristic. The dead zone of a sensor can be reduced by filtering out noise that would otherwise overshadow a signal representing the near-field region of a scene. The noise can be filtered by subtracting a polynomial curve from a time-domain signal representing the scene after fitting the polynomial curve to a representative signal generated based on previous scene scans.

Abstract: A method for extension of unambiguous range and velocity of a weather radar. To avoid pulse overlaying, the pulse repetition time of a single pulse can be extended such that any return echo will arrive at the radar before the next pulse is transmitted. When pulse repetition time is increased, the maximum unambiguous range increases while the maximum unambiguous velocity decreases. The pulse overlaying can be avoided if consecutive pulses are sent on different frequencies that are far enough from each other to allow separation of pulses arriving simultaneously at the radar. When different frequencies are used an unknown phase difference is generated by distributed atmospheric targets to the return signals. This normally prevents use of the shorter pulse repetition time for velocity calculation.

Abstract: One aspect of this disclosure relates to a method for processing a received, modulated radar pulse to resolve a radar target from noise or other targets. According to an embodiment of the method, a radar return signal is received and samples of the radar return signal are obtained. A minimum mean-square error (MMSE) pulse compression filter is determined for each successive sample. The MMSE filter is separated into a number of components using contiguous blocking, where each component includes a piecewise MMSE pulse compression filter segment. An estimate of radar range profile is obtained from an initialization stage or a previous stage. The piecewise MMSE pulse compression filter segments are applied to improve accuracy of the estimate. The estimate is repeated for two or three stages to adaptively suppress range sidelobes to a level of a noise floor. Other aspects and embodiments are provided herein.