Abstract: A method of detecting, by means of a SAR radar, objects that change with time within a ground area. The SAR radar is supported by a platform in essentially rectilinear motion during a synthetic aperture and the ground area is reproduced at least twice in succession from different synthetic apertures. A two-dimensional SAR image is generated from each synthetic aperture. The SAR images are matched with each other by a method in which each image position in one image is associated with the same ground area in the other image, the images being filtered, knowing location data for the antennae and based on the fact that the cylinder geometry of the SAR images is projected onto the ground surface, so that only common spectral components of the reflectivity of the ground are extracted and used in the matching.

Abstract: In a method for operating a rotating synthetic aperture radar system that works with pulse frequency or in FM-CW operation in order to detect, penetrate and evaluate objects that are located vertically below the helicopter carrying the ROSAR device, pixels are determined using their own specific doppler histories.

Abstract: A ROSAR wire detection method is based upon ROSAR focusing of entire segments of wire. By generating a wire reference signal comprised of a sum of coherent reference signals, the basis for reliable wire detectability is provided.

Abstract: An antenna section radiates a pulse beam and receives its reflected wave, and a signal processing section observes a rain or cloud occurring region within a covered area based on a signal intensity of the reflected wave. In this case, to obtain wind direction and velocity information for the rain or cloud occurring region, the signal processing section observes Rayleigh scattering-induced Doppler echo components in that region to calculate the wind direction and velocity from a result of the observation. To obtain the wind direction and velocity information for a region other than the rain or cloud occurring area, the beam formed by the antenna section is directed toward the region to be observed so that the signal processing section can observe Bragg scattering-induced echo components based on a received signal of the reflected wave to calculate the wind direction and velocity from a result of the observation.

Abstract: A multi-stage processing system receives data from signals that indicate information related to scatterers, such as signals from a Doppler scanning system. The multi-stage processing system tracks allowed processing time for the data. The multi-stage processing system performs a first stage of processing for the data to generate first estimates of spectral moments for the signals. The multi-stage processing system performs additional stages of processing for the data as the allowed processing time permits and stops the additional stages of processing for the data when the allowed processing time expires. The additional stages of processing may comprise generating second estimates for at least some of the spectral moments. The additional stages of processing may use methods having increasing complexity and accuracy.

Abstract: A radar signal processing method and system for detecting target objects of unknown acceleration and having low SNRs which reduces the computational burdens and provides a more efficient way of performing the operation of non-coherent integration. Radar signal processing is conducted according to a predetermined scheme in which partially processed received signal data is selectively stored and reused, reducing redundant processing. The radar system receives return signals frequency shifted from a predetermined frequency scheme by unknown amounts. The received signals are coherently integrated transforming them into frequency domain templates which are non-coherently arranged into an array matrix. The data of the frequency domain templates are processed to form presums which are stored for use in forming higher level presums and for forming acceleration bins. Once the acceleration bins have been formed, they are analyzed to detect the presence of target object return signals.

Abstract: A radio altimeter using a linear oscillator to send out a continuous wave that is frequency modulated linearly between two boundary values sends the antenna installation an incident signal, collects the signal reflected by the installation and examines it. This incident signal may be that of the linear oscillator. For the reception antenna installation, this means providing for a rerouting in order to direct a small part of the signal of the oscillator to this installation. In the case of the transmission antenna installation it is enough to provide for a rerouting that injects the signal reflected by this installation into the reception channel. Application to all the FM/CW radio altimeters.

Abstract: A high resolution cross correlation, coherent integration type spectrum analyzer for use in obtaining detailed spectral signatures of subsurface and surface vessels correlates short discontinuous records of the incoming signal with reference signals of known frequencies and accumulates the results to establish cross correlation over a relatively long total record made up of the short discontinuous record segments, with the long combined record being responsible for the high resolution of the system.

Abstract: A robotically controlled steerable gimbal mounted virtual broadband hyperspectral sensor system and methods provide a highly mobile, rapidly responsive and innovative system of locating targets and exploiting hyperspectral and ultraspectral imaging and non-imaging signature information in real-time from an aircraft or ground vehicles from overhead or standoff perspective in order to discriminate and identify unique spectral characteristics of the target. The system preferably has one or more mechanically integrated hyperspectral sensors installed on a gimbal backbone and co-boresighted with a similarly optional mounted color video camera and optional LASER within an aerodynamically stable pod shell constructed for three-dimensional stabilization and pointing of the sensor on a direct overhead or off-nadir basis.

Abstract: A Doppler-based radar system and related method are provided for determining the direction and speed of at least one selected target traveling in the same lane as a moving patrol vehicle supporting the radar system independent of the direction of the target relative to the platform. The radar system includes an oscillator to generate a signal, an antenna to transmit the signal toward the at least one target and to receive a return signal reflected from the at least one target, a turnstile in communication with the antenna for receiving the return signal and forming processing signals which are different in phase, and circuitry for determining the direction of the at least one target relative to the platform. In particular, samples of the processing signals are transformed into the frequency domain and cross-correlated forming cross-correlation components.

Abstract: A single-antenna short-range radar transceiver emits 24 GHz RF sinewave packets and samples echoes with strobed timing such that the illusion of wave propagation at the speed of sound is observed, thereby forming an ultrasound mimicking radar (UMR). A 12 GHz frequency-doubled transmit oscillator is pulsed a first time to transmit a 24 GHz harmonic burst and pulsed a second time to produce a 12 GHz local oscillator burst for a sub-harmonically pumped, coherently integrating sample-hold receiver (homodyne operation). The time between the first and second oscillator bursts is swept to form an expanded-time replica of echo bursts at the receiver output. A random phase RF marker pulse is interleaved with the coherent phase transmitted RF to aid in spectrum assessment of the radar's nearly undetectable emissions.

Abstract: A series of police doppler single mode radars and a multimode police doppler radar, all with direction sensing capability are disclosed. A quadrature front end which mixes received RF with a local oscillator to generate two channels of doppler signals, one channel being shifted by an integer multiple of 90 degrees in phase relative to the other by shifting either the RF or the local oscillator signal being fed to one mixer but not the other. The two doppler signals are digitized and the samples are processed by a digital signal processor programmed to find one or more selected target speeds. Single modes disclosed are: stationary strongest target; stationary, fastest target; stationary, strongest and fastest targets; moving, strongest, opposite lane; moving, strongest, same lane; moving, fastest, opposite lane; moving, fastest and strongest, opposite lane; moving, fastest, same lane; moving fastest and strongest, same lane.

Abstract: The invention relates to a method for measurement of the radar target cross section of an object with both moving and fixed parts, which method comprises a first measurement with high frequency resolution, from which information can be extracted on modulations in the signal received that derive from moving parts of the object and fixed parts of the object respectively. The invention is characterized in that the method comprises a second measurement with high range resolution, and filtering of the measuring result obtained from the second measurement, which filtering is performed around a certain frequency that is obtained by means of the measuring result from the first measurement. The first measurement is preferably given a high frequency resolution in that it is performed with a narrow-band waveform, and the second measurement is suitably given a high range resolution in that it is performed with a broadband waveform.

Abstract: The present invention relates to a CW radar method for measuring distances between and relative speeds of a vehicle and one or more obstacles. The present invention further provides that the transmission (s(t)) can be composed of at least four consecutive chirps (A, B, C, D), each having different slopes. The intersection points of all lines in the distance-relative speed diagram from two chirps (A, B) can be calculated from all the ascertained frequency positions K1,n and K2,p. To validate those intersection points, one may observe whether a peak exists in the Fourier spectrum of a third chirp C at a frequency position K3,q, whose assigned line intersects a surrounding area of the intersection point in the distance-relative speed diagram.

Abstract: A system and method for enhancing turbulence detection, display and alerting with avionics weather radars which includes automatically making multiple scans, measuring a wind velocity gradient at varying elevations, and comparing the measured gradient to known predetermined wind velocity gradients over known elevation variations, wherein the predetermined gradients have known vertical shear components, and using a vertical shear component information in making determinations regarding the existence of turbulence.

Abstract: A pulse Low Probability of Intercept (LPI) signal discriminator has a soft-limiting IF amplifier chain for receiving an IF signal to soft-limit any high-peak IF signals in the IF signal and a high-peak amplitude compressive circuit followed by an integrator which integrates the signal over a predetermined time to produce a high output when a LPI signal is present. The integrator is connected to a threshold detector which outputs a trigger signal when a high output from the integrator is received. In a receiver having a plurality of channels for received signals from a number of antenna, one channel for each antenna, the received signals are down converted to IF signals and applied to analog-to-digital converters (ADCs) which are connected to a digital processor.

Abstract: The present invention discriminates between moving targets and stationary targets in order to measure distances and speeds of the targets without producing a false target. The invention transmits signals whose modulating frequencies ascend or descend to a target, and receives signals reflected from this target. A frequency spectrum of a beat signal of each target is detected during a modulating frequency ascent period and a modulating frequency descent period. The frequency spectrum of the modulating frequency ascent period and the frequency spectrum of the modulating frequency descent period are used to set a reference spectrum. The reference beat frequencies of either the moving targets or the stationary targets are detected based upon the reference spectrum.

Abstract: The present invention relates to a method for generating a three-dimensional image of a ground area by means of a radar with a synthetic aperture, a SAR radar, which is supported by a platform moving in an essentially rectilinear manner. The method is characterized by the following steps. Advancing the platform such that at least two images of the ground are created with great difference in the angle of illumination. Transmitting radar pulses with a fractional bandwidth which is larger than or equal to 0.1, and using in the computations an aperture angle which is larger than or equal to 0.1 radians. Detecting the reflected radar pulses with amplitude and phase. For each pulse, measuring and storing the position of the antenna that transmits and the antenna that receives the pulse. Computing a two-dimensional SAR signal per synthetic aperture.

Abstract: A satellite architecture and method for microwave interferometry radiating incrementally accumulating holography, used to create a high-gain, narrow-bandwidth actively-illuminated interferometric bistatic SAR whose VLBI has a baseline between its two bistatic apertures, each on a different satellite, that is considerably longer than the FOV, in contrast to prior art bistatic SAR where the interferometer baseline is shorter than the FOV. Three, six, and twelve satellite configurations are formed of VLA satellite VLBI triads, each satellite of the triad being in its own nominally circular orbit in an orbital plane mutually orthogonal to the others of the triad. VLBI pairs are formed by pairwise groupings of satellites in each VLA triad, with the third satellite being used as a control satellite to receive both Michelson interferometric data for phase closure and Fizeau interferometric imaging data that is recorded on a holographic disc, preserving phase.

Abstract: A motion detector based on the Doppler principle contains a microwave module for emitting a microwave signal containing at least two frequencies into a room under surveillance and for receiving the radiation reflected from the latter. An evaluation stage is connected to the microwave module and generates first and second Doppler signals from the received radiation. The first and second Doppler signals have a phase difference which is proportional to the distance of an object reflecting the microwave signal. The phase difference is determined by an integral transformation. In addition, the relative size of an object and the direction of travel of an object reflecting the microwave signal can be determined by the evaluation stage.

Abstract: The passive polarimetric microwave radiometer is a simple and low cost radiometric icing detection system that operates over a suitable set of frequency bands in the millimeter wave region of the spectrum to provide useful signatures for detecting aircraft icing conditions. This basic passive polarimetric microwave radiometer observes along a single line of sight and consists of a dual polarization dual frequency radiometer that is pointed in the direction of interest, such as the projected flight path, and operates at a frequency which is sensitive to the polarizing effects of hydrometeors. The passive polarimetric microwave radiometer could also observe in a horizontal plane around the aircraft or ground station and include both vertical and horizontal scanning capability.

Abstract: A radar detection process includes computing a derivative of an FFT output signal to detect an object within a specified detection zone. In one embodiment, a zero crossing in the second derivative of the FFT output signal indicates the presence of an object. The range of the object is determined as a function of the frequency at which the zero crossing occurs. Also described is a detection table containing indicators of the presence or absence of an object within a respective radar beam and processing cycle. At least two such indicators are combined in order to detect the presence of an object within the detection zone.

Abstract: The invention relates to a radar distance measuring device. An especially linear frequency-modulated high frequency signal is emitted via an antenna and mixed with an echo signal reflected by a target object whose distance is to be determined. The distance of said target object can then be calculated by analyzing the frequency of the mix result. The aim of the invention is to improve the distance resolution or increase the accuracy of measurement. To this end, a first frequency analysis is first carried out to obtain a rough analysis result. Said rough analysis result is used to control a filtering device which then restricts the mix result in its time range to a segment around the frequency of the target object. A discrete Fourier transformation is then carried out for this segment in order to produce an analysis result with a more refined scanning step than the first frequency analysis.

Abstract: A system and method for providing remote viewing of satellite transponder plots. The system and method piovides for remote viewing of transponder plots derived from transponders located on a satellite that communicate with ground terminals having an antenna. The system comprises an antenna switch for receiving transponder signals from the antenna. A spectrum analyzer is coupled to the antenna switch for generating transponder plots. An equipment control computer is coupled to the antenna switch and the spectrum analyzer that selectively routes signals from the antenna switch to the spectrum analyzer and routes transponder plots generated by the spectrum analyzer. A server computer is coupled to the equipment control computer that stores the transponder plots generated by the spectrum analyzer that are routed by the equipment control computer.

Abstract: For optimizing the computing expenditures when using STAP filters in real-time systems, the determination of the filter coefficients and the filtering of radar source data of the distance Doppler matrices {right arrow over (X)}left and {right arrow over (X)}right of two adjacent reception channels are carried out in the frequency domain. On the basis of {right arrow over (X)}left and {right arrow over (X)}right, a distance Doppler matrix {right arrow over (Y)}clutterfree is created, at which the echoes of fixed targets are suppressed and the echoes of moving targets a coherently intensified.

Abstract: A weapons detector (12) and method utilizing radar. The system comprises a transmitter (27) for producing an output (14) of frequencies of a set of self-resonant frequencies of weaponry; an antenna (28) directing the transmitter output toward locations potentially having weaponry and collecting backscattered signals (15); a receiver (29) receiving the backscattered signals (15) and operating over a range of the self-resonant frequencies; and a signal processor (30) for detecting the presence of a plurality of the self-resonant frequencies in the backscattered signals (15). Accuracies of greater than 98% can be obtained at distances, preferably between 4-15 yards. The weapons detector (12) is capable of detecting metal and non-metal weapons (16) on a human body (13) in purses, briefcases and under clothing; and discerning weapons (16) from objects such as belt buckles, coins, keys, calculators, cellular phones.

Abstract: This invention concerns a procedure for the elimination of interferences, such as pulses and linear chirps, in a radar unit of the FMCW type According to the procedure, the useable signal in the form of a beat signal, is subjected to time-frequency division of the type STFT for division of the signal into narrow-band frequency bands. Interference is detected and eliminated in each frequency band, after which the time signal freed from interference and its Discrete Fourier Transform, DFT, are calculated from the time-frequency division in narrow-band frequency bands.

Abstract: An antenna section radiates a pulse beam and receives its reflected wave, and a signal processing section observes a rain or cloud occurring region within a covered area based on a signal intensity of the reflected wave. In this case, to obtain wind direction and velocity information for the rain or cloud occurring region, the signal processing section observes Rayleigh scattering-induced Doppler echo components in that region to calculate the wind direction and velocity from a result of the observation. To obtain the wind direction and velocity information for a region other than the rain or cloud occurring area, the beam formed by the antenna section is directed toward the region to be observed so that the signal processing section can observe Bragg scattering-induced echo components based on a received signal of the reflected wave to calculate the wind direction and velocity from a result of the observation.

Abstract: An obstacle detection includes a transmission leakage transmission path, a receiving leakage transmission path opposite to the transmission leakage transmission path, a spread spectrum signal generation means connected to an end of the transmission leakage transmission path and generating a spread spectrum signal for detection of an obstacle for radiation from the transmission leakage transmission path. A correlation means is connected to an end of the receiving leakage transmission path so as to calculate a level of correlation between a reference spread spectrum signal and a spread spectrum signal received by the receiving leakage transmission path. A detecting means detects an obstacle in accordance with a change in the level of correlation calculated by the correlation means.

Abstract: An FM-CW radar is provided which may be employed in anti-collision systems or cruise control systems installed in moving objects such as automotive vehicles. The radar analyzes a beat signal in frequency to produce peak frequency components in a modulated frequency-rising range wherein the frequency of a frequency-modulated radar wave transmitted from the radar increases and a modulated frequency-falling range wherein the frequency of the radar wave decreases. If one of peak frequency pairs, each of which is made up of each of the peak frequency components in the modulated frequency-rising range and one of the peak frequency components in the modulated frequency-falling range, lies within a given lower frequency range, the radar identifies the one of the peak frequency pairs as radar data arising from a moving object appearing suddenly in a radar detection zone.

Abstract: Dual path detection processing in which a low SNR signal processor detects signals over a limited range of low acceleration values and a high SNR signal processor detects signals over a wider range of acceleration values. The low SNR signal processor uses acceleration bins formed from a noncoherent FFT array to detect low SNR signals of far away objects which tend to have lower angular acceleration. Because close proximity target objects tend to have higher SNR return signals, it is not necessary to rely on acceleration bins formed from an FFT array for signal detection. Close proximity targets with high SNR can often be detected in individual coherently integrated FFT templates, despite the likelihood of large acceleration uncertainty from higher angular acceleration rates.

Abstract: The present invention relates to multi-function, multi-channel digital receiver architecture for performing three distinct receiver functions including simultaneous intrapulse analysis, direction finding and LPI signal detection; for determining parameters of incoming signals, comprising a plurality of receiver channels, each channel including a respective antenna for receiving the signal; a down-converter for converting the signal to an intermediate frequency (IF) signal; and an analog-to-digital converter operatively coupled to receive the IF signal and to provide a digital signal at a sampling rate, the digital signal being indicative of the amplitude and phase of the received signal in the channel, and a digital processor operatively coupled to receiving the digital signals from each of the plurality of channels for determining the amplitude and phase intrapulse profiles; by combining the amplitude and phase intrapulse profiles from all of the plurality of channels to provide both intrapulse and conventio

Abstract: The computation system of the present invention comprises an improved method of moment estimation for devices which measure spectra as a function of range or time. The preferred embodiment of this system is illustrated as part of an automated meteorological monitoring system for the accurate real time detection of meteorological phenomena, such as winds, wind shear and turbulence. This automated meteorological monitoring system uses a standard weather radar transmitter to scan a predetermined volume of space with a stream of radar pulses to determine the characteristics of meteorological phenomena that are extant in the predetermined volume. The computation system of the present invention utilizes novel signal processing algorithms in the improved method of moment estimation to excise the valid data from the returns echoes, which are corrupted by the presence of contaminating signals.

Abstract: A radar apparatus is provided which includes a transmitter, a receiver, and a signal processor. The transmitter produces a transmit signal which is so modulated in frequency as to change with time cyclically and transmits the transmit signal as a radar wave. The receiver selectively establishes communication with one of receiving antennas and changes the communications with the receiving antennas in sequence in a cycle shorter than a cycle of a change in the frequency of the transmit signal to supply a series of signal components of input signals produced by the receiving antennas. The receiver mixes the series of signal components with a local signal having the same frequency as that of the transmit signal to produce a beat signal. The signal processor samples the beat signal to analyze frequency components thereof to determine the distance to, relative speed and azimuth of a target.

Abstract: A broadband radio receiver of the type usable in receiving and identifying the pulsed signals of radar transmitters in an electronic warfare environment. The receiver includes signal presence detecting apparatus in the form of a time domain signal detection apparatus usable in maintaining complex signal processing portions of the receiver, such as its fast Fourier transform generation circuit, in quiescent low energy dissipating status until needed to perform signal analysis. Such energy conservation enables use of the receiver in energy limited remote or space received environments. Energy conserving “clockless logic” or “null convention logic” is preferably used in embodying greater energy dissipating portions of the receiver.

Abstract: A radar apparatus of the present invention is provided with a reception array antenna having a plurality of antenna elements, a first bearing detector for detecting a bearing of a target by carrying out signal processing on individual element signals received on an element-by-element basis through the respective antenna elements, and a second bearing detector for detecting a bearing of a target by carrying out signal processing different from that of the first bearing detector, on the individual element signals received through the respective antenna elements. Since the radar apparatus is provided with the two detectors of the first bearing detector and second bearing detector as means for acquiring the target bearing, both or either one of the results of detection by the two detectors can be selectively utilized as occasion demands.

Abstract: The invention proposes a novel method for using the signals provided by an airborne FM/CW radio altimeter, allowing to perform an analysis of the ground overflown by an aircraft for the purpose of, for example, identifying it, or alternatively of recognizing it. The method of the invention consists in analyzing, in the frequency domain, the shape of the spectrum of the beat signal generated by said radio altimeter to characterize said ground so as to extract from it information relating to the reflectivity of said ground.

Abstract: A Two-Stage Hybrid algorithm offers significant improvement in the false alarm rate and detection performance of Space-Time Adaptive Processing in non-homogeneous environments for both radar and digital communications. The first stage analyzes data from a range cell of interest by direct data domain processing, suppressing discrete interferers within the range cell of interest. The second stage implements a purely statistical STAP algorithm, preferably an enhanced version of the Joint-Domain Localized (“JDL”) statistical algorithm. For radar this second stage estimates the interference within the range cell of interest from the surrounding range cells. For a communications system, the second stage estimates the covariance matrix of the interference from the entire data block. For both radar and communications, an adaptive filter that suppresses the interference is generated from the estimate by second-order statistics.

Abstract: The invention relates to a method for measurement of the radar target cross section of an object with both moving and fixed parts, which method comprises a first measurement with high frequency resolution, from which information can be extracted on modulations in the signal received that derive from moving parts of the object and fixed parts of the object respectively. The invention is characterized in that the method comprises a second measurement with high range resolution, and filtering of the measuring result obtained from the second measurement, which filtering is performed around a certain frequency that is obtained by means of the measuring result from the first measurement.

Abstract: Methods and apparatus for detecting objects are disclosed. In one embodiment of the invention, a person entering a secured or “Safe Zone™” is illuminated with low-power polarized radio waves. Differently polarized waves which are reflected back from the person are collected and measured. In a preferred embodiment of the invention, concealed weapons are detected by calculating the difference of a pair of differences between levels of different polarized reflected energy in the time domain, and by using signal processing methods and apparatus to improve the reliability of the detection process. Alternative embodiments of the invention may be used to detect a wide variety of objects other than concealed firearms. The invention may be used for inventory control or to thwart shoplifting.

Abstract: A system and method tests the frequency response of a linear time-invariant unit-under-test, such as an antenna. A test signal is generated at a selected frequency and modulated with a spread spectrum input excitation signal to produce a broadband test signal that is substantially wider than the bandwidth of a device-under-test. The test signal is transmitted from one of either the unit-under-test or test device to a responsive test device or unit-under-test. The test signal is demodulated by mixing an input excitation signal that is delayed and increased in steps, such that the difference in time generates an estimate of the impulse response of the unit-under-test. The test signal is correlated and integrated to filter out unwanted interference and reflections.

Abstract: The application measures a projectile velocity and an acceleration from radar track data. The air temperature and an air pressure are measured. The measured air temperature and the measured air pressure are extrapolated to the projectile's location for each instant in time a radar measurement made by the radar. The projectile's drag parameter is estimated at each time in the projectile's flight that the projectile's velocity and acceleration are estimated. The projectile's Mach number is estimated at each time in the projectile's flight. The drag coefficient is estimated. A functionally normalized drag parameter (FNDP) is formed. The FNDP is defined as the ratio of drag parameter of a reference projectile at each Mach number the drag is measured to the in-flight projectile's drag parameter at the corresponding Mach numbers. A weighted average of the resulting FNDP values is performed with respect to Mach number.

Abstract: Characteristics of a target are measured by a radar or sonar. Pulses (101, 102, 103) are transmitted and in between (X) the transmissions of pulses a signal is received which depends on the transmitted pulses and on the distribution of the characteristics measured at different ranges. The distribution at different ranges of the characteristics measured is determined by representing it by means of a substantially linear system of equations in which the variables are the values of the characteristics measured at desired ranges, and by solving the system of equations for the variables. The transmitted pulses form a cyclically repeated pulse code or a continuously changing pulse train.

Abstract: An apparatus and method for detecting an object and determining the range of the object is disclosed. A transmitter, coupled to an antenna, transmits a frequency-modulated probe signal at each of a number of center frequency intervals or steps. A receiver, coupled to the antenna when operating in a monostatic mode or, alternatively, to a separate antenna when operating in a bistatic mode, receives a return signal from a target object resulting from the probe signal. Magnitude and phase information corresponding to the object are measured and stored in a memory at each of the center frequency steps. The range to the object is determined using the magnitude and phase information stored in the memory. The present invention provides for high-resolution probing and object detection in short-range applications. The present invention has a wide range of applications including high- resolution probing of geophysical surfaces and ground- penetration applications.

Abstract: For two-dimensional processing of spotlight SAR data into exact image data, the spotlight SAR raw data are divided into azimuth sub-apertures and transformed into the range-time/azimuth-frequency domain through short azimuth FFTs. The obtained data are multiplied by a frequency-scaling function Hf(fa, tr; r0) and transformed into the two-dimensional frequency domain through short range FFTs, multiplied by an RV-phase-correction function HRVP(fr) and subsequently transformed back into the range time/azimuth-frequency domain through short range IFFTs. The data formed in this manner are multiplied by the inverse frequency-scaling function Hg(fa, fr), then transformed back into the two-dimensional frequency domain, multiplied by the phase-correction function Hkorr(fa, fr) and the azimuth-scaling function Ha(fa, fr), and transformed back into the range-frequency/azimuth-time domain through short azimuth FFTS.

Abstract: The present invention relates to a method of detecting and classifying objects using radar. The method means that a broadband radar signal comprising wavelengths that coincide with characteristic lengths of targets to be detected and classified is transmitted. Further, a returned echo signal is received and analysed, at which a signal analysis in a combined time-frequency domain is used, which comprises determining characteristic frequencies in the signal return and their mutual time relations. Finally, a comparison with the corresponding stored values of an analysis of possible targets is performed.

Abstract: An algorithm for emitter identification of a transmitting platform using microphone keyclick analysis, and a system utilizing said algorithm, wherein said algorithm processes audio signals to detect transmission activity on a radio channel in the audio frequency range, detects the boundaries of transmitter keyclicks at the beginning and end of said transmission; extracts keying envelopes from said detected keyclick boundaries; and analyzes said keying envelopes to extract features characteristic of said keyclicks. The algorithm and system then proceed to execute a decision function based on said extracted characteristic features to identify the platform of said transmitter based on the features of said keyclick. A second algorithm, which may be executed in parallel with the first by said system, processes said transmission data using a fast fourier transform, detecting gaps in said processed transmission data.

Abstract: An algorithm for emitter identification of a transmitting platform using spectral energy analysis, and a system utilizing said algorithm, wherein said algorithm processes audio signals from transmission data using a fast fourier transform, detecting gaps in said processed transmission data. It then extracts spectral features consisting of normalized energy per unit frequency from said gaps. The algorithm and system then proceed to execute a decision function based on said extracted characteristic features to identify the platform of said transmitter based on said features. A second algorithm, which may be executed in parallel with the first by said system, processes the same transmission data to detect transmission activity on a radio channel in the audio frequency range, and to detect the boundaries of transmitter keyclicks at the beginning and end of said transmission.

Abstract: The invention relates to a method for monitoring the earth's surface with a moving aircraft using a radar sensor with a synthetic aperture. In order to produce high resolution radar images, the flight parameters of the aircraft are also required. According to the inventive method, key parameters, such as speed and acceleration, are detected in the sight line of the radar sensor from the radio signals received. One of the advantages of the invention is that an inertial navigation system (INS) is no longer required for this purpose.

Abstract: A series of police doppler single mode radars and a multimode police doppler radar, all with direction sensing capability are disclosed. A quadrature front end which mixes received RF with a local oscillator to generate two channels of doppler signals, one channel being shifted by an integer multiple of 90 degrees in phase relative to the other by shifting either the RF or the local oscillator signal being fed to one mixer but not the other. The two doppler signals are digitized and the samples are processed by a digital signal processor programmed to find one or more selected target speeds. Single modes disclosed are: stationary strongest target; stationary, fastest target; stationary, strongest and fastest targets; moving, strongest, opposite lane; moving, strongest, same lane; moving, fastest, opposite lane; moving, fastest and strongest, opposite lane; moving, fastest, same lane; moving fastest and strongest, same lane.