Abstract: A method for monitoring the function of ultrasonic sensors of a vehicle, an ultrasonic sensor of the vehicle emitting ultrasonic signals and receiving back reflected ultrasonic echoes. An instantaneous amplitude of a ground echo received by an ultrasonic sensor and an instantaneous vehicle position are determined. A reference threshold value or information regarding an expected ground echo amplitude is retrieved from a digital map as a function of the instantaneous vehicle position, the digital map being provided by a central unit. The instantaneous amplitude of the received ground echo is compared with a threshold value, a malfunction of the ultrasonic sensors being deduced if the threshold value is undershot and the threshold value being predefined by the reference threshold value or the threshold value being determined based on the information regarding an expected ground echo amplitude.

Abstract: Techniques are disclosed relating to geophysical surveying. In various embodiments, a computer system may access seismic data for a geological formation, where the seismic data is recorded, using one or more sensors, during a seismic survey in which a first vibratory source was driven using a first digital code for at least a first time interval. The first digital code, in some embodiments, may include a first plurality of subsections corresponding to portions of the first time interval. In some embodiments, the computer system may image a first location of the geological formation using a correlation of only a first sub-section of the first plurality of sub-sections with the seismic data. Further, in some embodiments, the computer system may image a second location of the geological formation using a correlation of two or more of the first plurality of sub-sections with the seismic data.

Abstract: The present invention relates to an electronic device for controlling an unmanned aerial vehicle and a control method therefor. The electronic device for controlling an unmanned aerial vehicle according to the present invention comprises: a first sensor for sensing a first direction; a second sensor for sensing a second direction opposite to the first direction; and a processor electrically connected to the first sensor and the second sensor, wherein the processor may be configured to: determine whether the unmanned aerial vehicle is located in a first environment on the basis of at least one sensing data obtained by the first sensor; control sensing operations of the first sensor and the second sensor according to the determination result; and control motion of the unmanned aerial vehicle on the basis of at least one sensing data obtained by the first sensor and the second sensor.

Abstract: An example apparatus includes a transducer to receive a reference signal and a reflected signal, the reflected signal being the reference signal after being reflected of a target; a filter to generate a band-pass reference signal and a band-pass reflected signal by filtering (A) reference signal samples associated with the reference signal and (B) reflected signal samples associated with the reflected signal; a correlator to generate a first correlation by correlating the reference signal samples with the reflected signal samples and a second correlation by correlating the band-pass reference signal with the band-pass reflected signal; and a delay estimator to determine a distance to the target based on the first correlation (coarse delay) and the second correlation (fine delay) and output a signal including the distance to the target.

Abstract: A vehicle, radar system for the vehicle and method of operating the vehicle is disclosed. The radar system includes a transmitter, a receiver and a processor. The transmitter transmits a source signal into a region proximate the vehicle. The receiver receives a reflected signal formed by reflection of the source signal from an object in the region. The processor obtains non-linear terms of a phase from the reflected signal and resolves a Doppler ambiguity of the object using the non-linear terms. A navigation system navigates the vehicle with respect to the object based on the resolved Doppler ambiguity.

Abstract: Parameters of a sweep signal that controls operation of a marine non-impulsive source can be set. Setting the parameters can include selecting a stop frequency of the sweep signal, defining a taper of the sweep signal, and adjusting an initial phase of the sweep signal. The parameters can be set such that a magnitude of an amplitude spectrum of a combined output of a marine impulsive source and the marine non-impulsive source is greater than or equal to a magnitude of an amplitude spectrum of a marine impulsive source output at frequencies below the stop frequency. A controller of the marine non-impulsive source can be programmed with the sweep signal having the parameters set to control the marine non-impulsive source.

Abstract: A synchronizer generates cross-products of In-phase (I) and Quadrature (Q) samples and stores the sign bits for the sine and cosine cross-products. The sign bits are compared to a local reference of a frame-start bit-sequence and the compare results accumulated as I and Q correlations for symbol and half-symbol sampling. Linear combinations of the accumulated I and Q correlations for the symbol and half-symbol sampling generate linear combination results for frequency bins that peak at a different implied Carrier Frequency Offset (CFO) settings. The maximum of the linear combination results is selected and the implied CFO setting for that frequency bin is applied to a demodulator to adjust the receiver's CFO setting and bit synchronization. Computational complexity is reduced since only the sign bit of each cross-product is retained for correlation with the frame-start bit-sequence. Linear combinations can support a wide CFO range.

Abstract: To acquire a beat frequency necessary for target extraction, target speed estimation, and Doppler influence detection by preventing the necessary beat frequency from overlapping unnecessary frequencies in a heterodyne processing result, an apparatus includes a wave receiver that receives a reflected wave of a chirp wave reflected from a target, and outputs a reception wave signal, a dual-sweep signal generator that generates a dual-sweep signal of the chirp wave, having a frequency which does not overlap that of the chirp wave, and a heterodyne processor that generates a beat frequency by multiplying the reception wave signal and the dual-sweep signal as a heterodyne signal.

Abstract: A signal evaluation system is provided for evaluating a first EM signal and a second EM signal for use in a passive coherent location system. The signal evaluation system includes: a spectrum detecting component that detects the first EM signal and the second EM signal; a signal characterization component that generates a first characterization of the first EM signal and to generate a second characterization of the second EM signal; and a ranking component that ranks the EM signals for use in the passive coherent location system. The first characterization is based on an amplitude associated with the first EM signal and one of range resolution, Doppler resolution, and combinations thereof associated with the first EM signal. The second characterization is based on an amplitude associated with the second EM signal and one of range resolution, Doppler resolution, and combinations thereof associated with the second EM signal.

Abstract: A sensor-controlled key system for a motor vehicle for releasing an access authorization and for actuating auxiliary functions includes a control device having an electronic key device. The key system further includes at least one optical sensor device with at least one optical sensor element. The optical sensor element has a beam path that defines at least two observation regions B1, B2, Bn. The control device has a switching function that switches observation regions B1, B2, Bn on and off in dependence on a verified or non-verified access authorization.

Abstract: Artefacts arising from imperfect extrapolation of a data set subjected to filtering operation are removed by forming a model of the extrapolated data, performing a filtering process on the model and the data set to form a filtered model and a filtered data set, and adaptively subtracting the filtered model from the filtered data set. The adaptive subtraction may employ a least-square error filter.

Abstract: A system and method is described for generating a confidence level for data generated by a beamforming acoustic beacon system. The system may include an audio emission device to emit a set of sounds corresponding to a set of predefined modal patterns into a listening area. The sounds may be detected by an audio capture device to produce a set of impulse responses corresponding to the modal patterns. The impulse responses may be processed to produce a set of window synthesized impulse responses for various angles. These window synthesized impulse responses may (1) be formed based on a weighted set of the modal patterns that were originally used to emanate sound and (2) seek to emulate a target beam, which is also composed of the same weighted modal patterns. A confidence level may be computed based on the difference between the window synthesized impulse responses and the target beam pattern.

Abstract: A radar system for detecting a target containing electronic components. The radar system includes a radiofrequency transmitter which generates a radar signal at a fundamental frequency. A modulator modulates the radar signal at a modulation frequency and the modulated radar signal is coupled to a transmission antenna. A receiver receives an echo from the radar signal. A filter isolates the harmonics of the fundamental frequency from the echo and a demodulator then compares the phase of the harmonics of the echo with the phase of the harmonics of the radar signal and generates an output signal representative thereof. An imaging algorithm receives the output signal and creates a two-dimensional image of the received echo and then displays that image on a display.

Abstract: Apparatus is provided for: storing at least one three-dimensional matrix C[M][N][K] of calibration data; performing singular value decomposition of each at least one three-dimensional matrix C[M][N][K] of calibration data to produce at least one first unitary rotation matrix U, at least one diagonal scaling matrix S and at least one second unitary rotation matrix V; and resizing each of the at least one first unitary rotation matrix U, the at least one diagonal scaling matrix S and the at least one second unitary rotation matrix V by removing dimensions therefrom, thereby producing resized matrices U, S and V. Corresponding decompression is also provided.

Abstract: An acoustic signal traversing a hot gas is sampled at a source and a receiver and is represented in overlapping windows that maximize useable signal content. Samples in each window are processed to represented in different sparsified bins in the frequency domain. Determining a signal delay between the source and the receiver from a summation of maximum smoothed coherence transform cross-correlation values of different data windows wherein a sparseness of a mean smoothed coherence transform cross-correlation of windows is maximized. Determining a set of delay times wherein outliers are deleted to estimate a time of flight from which a temperature of the hot gas is calculated.

Abstract: Spoof-detection and liveness analysis is performed using a software-based solution on a user device, such as a smartphone having a camera, audio output component (e.g., earpiece), and audio input component (e.g., microphone). One or more audio signals are emitted from the audio output component of the user device, reflect off a target, and are received back at the audio input component of the device. Based on the reflections, a determination is made as to whether the target is comprised of a three-dimensional face-like structure and/or face-like tissue. Using at least this determination, a finding is made as to whether the target is likely to be spoofed, rather than a legitimate, live person.

Abstract: The present invention relates to an apparatus for use in geophysical surveying. Geophysical surveying typically involves stimulating an area of interest with a seismic source (204) and detecting the response in a sensor array. The application describes a fiber optic distributed sensing apparatus having a source (112) of electromagnetic radiation for repeatedly launching interrogating electromagnetic radiation into an optic fiber (104) deployed in said of area interest, a sampling detector (116) for sampling radiation back-scattered from the fiber; and a processor (108) arranged to process the back-scattered radiation to provide, for each of a plurality of longitudinal sensing portions of optic fiber, an indication of any incident acoustic signals affecting that sensing portion. The sampling detector is arranged to acquire a plurality of diversity samples for each said longitudinal sensing portion.

Abstract: A method for calculating intermodulation noise generated with one or more land seismic sources. The method includes receiving seismic data generated by actuating the one or more land seismic source with a first sweep and a second sweep; calculating with a computing device a first earth response corresponding to the first sweep; calculating with the computing device a second earth response corresponding to the second sweep; and calculating the intermodulation noise based on the first and second earth responses. The second sweep is a time reverse sweep of the first sweep.

Abstract: There is provided a radar apparatus configured to extract peak signals which are obtained from a difference frequency between a transmission signal and a reception signal, and to derive information of the target on the basis of the extracted peak signals. A prediction unit predicts this time peak signal based on a peak signal obtained in previous time. An extraction unit extracts this time peak signal corresponding to the predicted peak signal from peak signals existing within a predetermined frequency range. The extraction unit extends the frequency range when this time peak signal corresponding to the predicted peak signal does not exist within the predetermined frequency range.

Abstract: An environment monitoring device in a motor vehicle having a signal generating device for generating a transmitted signal, at least one ultrasonic transducer for converting electric oscillations into acoustic oscillations and/or vice versa, and an evaluation device which evaluates an electric received signal in order to determine distances to objects in an environment of the motor vehicle, wherein the signal generating device is linked to the at least one ultrasonic transducer so that the ultrasonic transducer emits an ultrasonic transmitted signal into the environment in accordance with the electric transmitted signal, and the evaluation device is connected to the at least one ultrasonic transducer or at least one further ultrasonic transducer in order to receive the electric received signal. Also disclosed is a method for monitoring an environment by using a cross-correlation.

Abstract: The present invention relates to a method of non-destructive inspection of mechanical structures (2) by using vibratory waves in order to detect local defects and/or changes of state. According to the invention, the method comprises: a first training stage in which a transient vibratory excitation is injected into an inspection zone (Z) and the received signals are picked up and time reversed in order to constitute reference excitation signals; a second training stage in which the reference excitation signals are emitted simultaneously and the resulting diverging signals are picked up in order to constitute reference response signals; and a stage of inspecting the mechanical structure (2), in which the reference excitation signals are emitted, the resulting diverging signals are picked up, and the diverging signals are compared with the reference response signals.

Abstract: A method for acoustically sensing an area is described. An acoustic transmit pulse is transmitted into the area by an acoustic transducer and a received signal is acquired with the aid of the transducer, in order to receive the transmit pulse reflected back from the area. Within a post-pulse oscillation time of the transducer, which directly follows the emission of the transmit pulse, the actual phase response of the received signal is determined. In the event the actual phase response deviates from a predefined setpoint phase response, an object is detected within the area. Also described is a device for acoustically sensing an area, which is designed to carry out the method.

Abstract: There is provided a method and associated apparatus for measurement. Specifically, a method for determining a distance travelled by a signal in a medium, or the time of flight of a signal travelled. The method comprises considering an unambiguous range wherein the unambiguous range greater than a distance to be travelled by a signal. A signal is then transmitted across the distance to be determined, the signal comprising at least two frequency components, the frequency components based on the unambiguous range and the speed of the signal in the medium. The distance travelled (or the time of flight) is determined by using the variance of the received phase characteristics, such as phase angle) of one frequency component of the received signal with the received phase characteristics of another frequency component of the received signal.

Abstract: In an embodiment a semiconductor device correlates a received signal with a known pattern. A correlation output is used as a basis for forming a confidence reference level. The confidence reference level and the correlation output are compared to identify a peak in the received signal indicating that a present signal state of the received signal contains the known pattern.

Abstract: A method for detecting an object within a surrounding area of a vehicle, includes: repeatedly transmitting wave pulses into the surrounding area; repeatedly receiving wave pulses, which correspond to the transmitted wave pulses reflected by the objects; detecting the object with the aid of a signal representation of the received wave pulses, and ascertaining at least one signal characteristic of a first received wave pulse. The detecting of the object includes: comparing the curve in the form of the signal characteristic of the first received wave pulse to the curve of a further received wave pulse, which was received after the first received wave pulse, location information of the object being corrected in light of the comparison.

Abstract: A method and apparatus for passive determination of target data (R, K, V) associated with a target from measured and estimated bearing angles. The measured bearing angles (4) are determined by a sonar receiving installation (2) by directionally selective reception of sound waves which are emitted or sent from a target, and the estimated bearing angles are determined from estimated positions of the target. The bearing angle differences from estimated and measured bearing angles are minimized iteratively over a plurality of processing cycles, and a position of the target, on which the minimum is based, is determined as the optimized solution (12). Furthermore, limit values (10) are defined for the target data (R, K, V) to be determined, in order to exclude unrealistic target data as solutions.

Abstract: A system for measuring the height of bin contents includes transmitters for transmitting pulses of wave energy towards the upper surface of the contents and receivers for receiving echoes of the pulses and producing corresponding signals. The transmitters and receivers are distributed aerially above the contents. The system also includes a processing apparatus, for using the received signals to map the upper surface, that includes correlators that correlate pulse waveforms with the signals, and a beamformer. In one embodiment, the beamformer computes, from the signals considered as corresponding to echoes, of pulses from fewer synthetic transmitters, received at a synthetic receiver array, respective directions of arrival of the signals.

Abstract: An environment monitoring device in a motor vehicle having a signal generating device for generating a transmitted signal, at least one ultrasonic transducer for converting electric oscillations into acoustic oscillations and/or vice versa, and an evaluation device which evaluates an electric received signal in order to determine distances to objects in an environment of the motor vehicle, wherein the signal generating device is linked to the at least one ultrasonic transducer so that the ultrasonic transducer emits an ultrasonic transmitted signal into the environment in accordance with the electric transmitted signal, and the evaluation device is connected to the at least one ultrasonic transducer or at least one further ultrasonic transducer in order to receive the electric received signal. Also disclosed is a method for monitoring an environment by using a cross-correlation.

Abstract: A position measurement apparatus and methodology is provided. Embodiments include a probe including an acoustic signal source, an optical signal source, and a probe processor for driving the signal sources such that the signals of the acoustic source and the optical source have a known temporal relationship to each other. A receiver receives the optical and acoustic signals, and a processor communicates with and controls the probe and the receiver, and processes data from the receiver. The acoustic signal source is a sinusoidally varying acoustic energy source, and the acoustic signal received by the receiver comprises a sinusoidal signal. The processor correlates the received sinusoidal signal to a mathematical reference sinusoidal signal, and determines a specific cycle and a specific phase as a time of flight measurement point based on the correlation.

Abstract: A method of obtaining information about the positions of sources in a marine seismic source array that has N seismic sources, including at least Nunique types of sources that are nominally non-identical to one another, where 1?Nunique?N?1. The method comprises measuring the pressure field at M independent locations of the N sources, where M>Nunique, and obtaining information about the positions of sources from the M pressure measurements and from the constraint that at least two of the sources are nominally identical to one another.

Abstract: A target detection device includes: a sound source which projects a sound pulse; a transducer array disposed in a region for receiving a forward scattered wave from an object in the propagation environment; an addition processing unit which extracts only a signal of the forward scattered wave by applying vector addition processing on a reference signal in a reference sound field received when an obstacle exists in the propagation environment and a mixed signal in a mixed sound field received when the target exists with the obstacle; a phase conjugation determination unit which checks whether a phase conjugacy is established by receiving the signal of the extracted forward scattered wave and employing a passive phase conjugation for determining the reference sound field; and a time reversal processing unit which generates a time reversal signal on condition that the phase conjugation determination unit judges that the phase conjugacy is established.

Abstract: Systems and methods for sonar image feature extraction, which fit a parameterized statistical model to sonar image data to extract features that describe image textures for follow-on pattern classification tasks. The systems and methods estimate the parameters of an assumed statistical model from the pixel values in the sonar images. The parameters of the distribution can then be used as features in a discriminant classifier to perform tasks such as texture segmentation or environmental characterization. The systems and methods divide a sonar image into separate overlapping cells. The ACF parameters of each cell are sequentially estimated using various methods. Based on the ACF parameters obtained, each cell is assigned a label via a pattern classification algorithm. The labeled image can be used in target recognition, environmental characterization and texture segmentation.

Abstract: A method, which allows, in an acoustic pulse-echo ranging system, the direct use of a digitized raw echo signal for correlation-based echo distance estimation, where an acoustic pulse having a carrier frequency is transmitted, a digital expected echo shape is provided with a time resolution higher than the carrier frequency, an echo is received from the acoustic pulse, the received echo is sampled and digitized at a sampling frequency higher than the carrier frequency, correlation values are created from the digitized received echo and the digital expected echo shape, the correlation values are weighted by emphasizing stronger correlation values, and the echo distance is determined from the center of mass of the weighted values.

Abstract: A system for small space positioning comprises a transmitting element at a fixed and known location, which transmitting a modulated continuous wave, for example an ultrasonic wave, having a continuous carrier signal part and a base-band signal modulated thereon. The transmitting element transmits the modulated continuous wave over a range in which an object to be positioned may appear. A receiving element receives signals transmitted by the transmitting device and reflected by the object, and a position detection element determines a position of the object from analysis of both the carrier signal part and the base-band signal received from the reflected signal.

Abstract: A dual frequency ultrasonic locationing system includes an emitter operable to emit two different ultrasonic frequencies simultaneously in one ultrasonic burst. A receiver with at least two microphones is operable to receive the ultrasonic burst. A correlator is operable to correlate the signals obtained from each microphone to derive a time difference of arrival of the ultrasonic burst at each microphone. The time difference of arrival of the ultrasonic signal from the emitter impinging on each microphone of the receiver is utilized to determine a location of the emitter.

Abstract: A method for processing data, in particular an image representative of an observation zone in which is situated an object arranged with respect to a reference plane.

Abstract: A system and method of range estimation are disclosed. In one embodiment, the method comprises transmitting beams through a medium towards a surface, receiving reflected signals from the surface, and estimating range to the surfaced based on the reflected signals and an estimate of sidelobe coupling of the beams.

Abstract: Embodiments of the present invention are directed to various enhanced discrete-universal denoisers that have been developed to denoise images and other one-dimensional, two-dimensional or higher-dimensional data sets in which the frequency of occurrence of individual contexts may be too low to gather efficient statistical data or context-based symbol prediction. In these denoisers, image quality, signal-to-noise ratios, or other measures of the effectiveness of denoising that would be expected to increase monotonically over a series of iterations may decrease, due to assumptions underlying the discrete-universal-denoising method losing validity. Embodiments of the present invention apply context-class-based statistics and statistical analysis to determine, on a per-context-class basis, when to at least temporarily terminate denoising iterations on each conditioning class.

Abstract: A method for detecting an object within a surrounding area of a vehicle, includes: repeatedly transmitting wave pulses into the surrounding area; repeatedly receiving wave pulses, which correspond to the transmitted wave pulses reflected by the objects; detecting the object with the aid of a signal representation of the received wave pulses, and ascertaining at least one signal characteristic of a first received wave pulse. The detecting of the object includes: comparing the curve in the form of the signal characteristic of the first received wave pulse to the curve of a further received wave pulse, which was received after the first received wave pulse, location information of the object being corrected in light of the comparison.

Abstract: Systems and methods for estimating the distance between a start point and a true endpoint in which at least two functions of differing resolutions are used. The method includes measuring a coarse distance between the start point and an intermediate point using the lower resolution function, the intermediate point comprising a point which is substantially within one unit of the higher resolution function away from the true endpoint. Next, a vernier distance is measured from the intermediate point to a vernier endpoint using the higher resolution function, the vernier endpoint being within a narrow, vernier error window of the true endpoint. Subsequently, the coarse and vernier distances are summed to obtain the estimated distance.

Abstract: A position detection system, includes at least one moving body (MB) including a transmission device simultaneously emitting a trigger signal indicating transmission timing and an ultrasonic signal obtained by modulating a signal of a frequency as a reference by pseudo random sequence data having high self-correlativity, and a reception device detecting MB position. The reception device includes ultrasonic reception units, a unit calculating a correlation value between a waveform of the ultrasonic signal and a model waveform of the pseudo random sequence, a unit subjecting the waveform of the ultrasonic signal and the model waveform to calculate a correlation value between the two waveforms, a unit calculating a propagation time of each ultrasonic to arrive at each of the ultrasonic reception units from trigger signal reception to correlation peak detection, and a unit calculating MB position from the ultrasonic propagation time and the interval length between the ultrasonic reception units.

Abstract: The present invention can find the exact location anywhere in the nautical world (latitude/longitude coordinates) by correlating or matching radar returns with maps produced by a digital nautical chart called a Chart Server, because each pixel location on the Chart Server maps can be traced back to a latitude/longitude coordinate. An obstacle avoidance module called a Chart Server provides digital nautical charts to create a map of the world. To determine the current world location of a vehicle, the invention combines the Chart Server maps with a radar return, which also appears to display prominent features such as coastlines, buoys, piers and the like. These return features from the radar are correlated or matched with features found in the Chart Server maps. The radar then reports its current location inside of its local map, which when translated to the Chart Server map, correlates to a latitude/longitude registration location.

Abstract: A method, which allows, in an acoustic pulse-echo ranging system, the direct use of a digitized raw echo signal for correlation-based echo distance estimation, where an acoustic pulse having a carrier frequency is transmitted, a digital expected echo shape is provided with a time resolution higher than the carrier frequency, an echo is received from the acoustic pulse, the received echo is sampled and digitized at a sampling frequency higher than the carrier frequency, correlation values are created from the digitized received echo and the digital expected echo shape, the correlation values are weighted by emphasizing stronger correlation values, and the echo distance is determined from the center of mass of the weighted values.

Abstract: The invention as disclosed is of a method to authenticate identify and trace sonar transmissions and echoes by embedding transparent, secure and robust digital watermarks in signal space, where the additional information incurs no cost in bandwidth. The complex short time Fourier transform is selected as the domain for embedding the digital watermark, secured by a secret key, in the time frequency representation of the signal. The watermark is designed through an iterative optimization step. This step insures that the watermarked sonar is also realizable. Selection of the time frequency region for watermarking is driven by avoidance of interference with the sonar itself, or in case of network operation, other watermarks. In addition, the selected time-frequency region remains robust to sound channel and other transmission effects. Sonar echoes are authenticated in the time-frequency plane by a correlation receiver tuned to the watermarked region using the secret key.

Abstract: The ultrasonic sensor having a switchable receive filter has a first bandwidth for a near measuring range of the ultrasonic sensor, and a second bandwidth for a distant measuring range of the ultrasonic sensor, the first bandwidth being greater than the second bandwidth.

Abstract: An object probing device includes: a sound source which projects a sound pulse within a propagation environment; a transducer array disposed in a region for receiving the forward scattered wave scattered forward from the object existing in the propagation environment; an addition processing unit which extracts only a signal of the forward scattered wave by applying vector addition processing on a reference signal in a reference sound field received by the transducer array when the object does not exist in the propagation environment and a mixed signal in a probe sound field received when the object exists; a time reversal processing unit which generates a time-reversed sound pulse by applying time reversal processing on the extracted forward scattered wave; and a phase conjugation determination unit which checks whether or not a phase conjugacy is established in the propagation environment by employing a passive phase conjugation to the time-reversed sound pulse.

Abstract: An active sonar system, a method associated therewith, and a computer-readable medium associate therewith, each provide a method of sonar signal processing. The method includes receiving a plurality of initial detections of a target and associated initial detection times, associated with sound transmitted at a pulse rate interval (PRI), and associated with received sound including echoes from a target. The echoes result from the transmitted sound. The method also includes analyzing the plurality of initial detection times with a pulse sorting transform configured to identify periodic PST detection times within the plurality of initial detection times that are equally spaced in time and that are representative of the echoes from the target.

Abstract: The invention is a method for improved active sonar using a singular value decomposition filtering and a Volterra-Hermite Basis Expansion to model real active sonar measurements. The fitting model minimizes the sum of the squared errors between a measured channel response, z(t), and model response, y(t), which is a fitted Volterra Series solution. The model requires as input an excitation waveform, x(t), to which is fitted the model response, y(t). A contracted broadband cross-ambiguity function is used to correct the excitation waveform for Doppler and range effects. Once completed, the modeled response can be used to determine the linearity or non-linearity of the channel effects. Appropriate measures can be utilized to reduce these effects on the measured channel response.

Abstract: A system and method of range estimation are disclosed. In one embodiment, the method comprises transmitting beams through a medium towards a surface, receiving reflected signals from the surface, and estimating range to the surfaced based on the reflected signals and an estimate of sidelobe coupling of the beams.

Abstract: The present invention refers to a system for detecting obstacles for vehicles, comprising at least one sensor able to transmit a detection signal and to receive an echo signal reflected off at least one obstacle, means of parametric evaluation of said received echo signal which comprise means of comparison between at least two successive echo signals for the determination of a reference echo signal able to define the position of at least one fixed obstacle with respect to said at least one sensor.