Abstract: Systems and methods are provided for interrogating a moving acoustic source using radar and processing data using a selection of motion compensation techniques adapted from synthetic aperture radar (SAR) to remove the effects of linear and nonlinear target motion so that the range-Doppler map retains only vibration information in the Doppler dimension. Vibration and sound waveforms can thus be selectively reproduced at specific ranges directly from the radar baseband waveform, without the need for additional complex analysis or audio processing.

Abstract: Systems and methods are provided for imaging that demonstrably outperform previous approaches (especially compressive sensing based approaches). Embodiments of the present disclosure provide and solve an imaging cost function via a stochastic approximation approach. By doing so, embodiments of the preset disclosure provide a significant means of generalization and flexibility to adapt to different application domains while being competitive in terms of computational complexity.

Abstract: Systems and method are provided for three-dimensional (3D) imaging by using Doppler and interferometric processing techniques for general planar phased arrays. Systems and methods according to embodiments of the present disclosure incorporate motion compensation techniques in a way that utilizes the full aperture of a phase array. Embodiments of the present disclosure can be applied to a variety of different radar imaging modalities, including X-band and millimeter wave (MMW) regimes.

Abstract: Systems and methods are provided for imaging that demonstrably outperform previous approaches (especially compressive sensing based approaches). Embodiments of the present disclosure provide and solve an imaging cost function via a stochastic approximation approach. By doing so, embodiments of the preset disclosure provide a significant means of generalization and flexibility to adapt to different application domains while being competitive in terms of computational complexity.

Abstract: Systems and method are provided for three-dimensional (3D) imaging by using Doppler and interferometric processing techniques for general planar phased arrays. Systems and methods according to embodiments of the present disclosure incorporate motion compensation techniques in a way that utilizes the full aperture of a phase array. Embodiments of the present disclosure can be applied to a variety of different radar imaging modalities, including X-band and millimeter wave (MMW) regimes.

Abstract: A method of reconstructing an image of an object, the method including: determining, by a plurality of sensors, a waveform based on the object, wherein the plurality of sensors view the object from a plurality of directions; determining, by a pre-processing module, a plurality of measurements of the object using the waveform, wherein the plurality of measurements are arranged in a vector form; determining, by an option module, a sampling matrix, a dictionary, and a noise factor, wherein the sampling matrix represents a geometric arrangement of the plurality of sensors, and the dictionary is pre-selected by the option module; estimating, by an estimation module, a coefficient vector using the measurements, the sampling matrix, and the noise factor; and reconstructing, by a reconstruction module, the image, using the coefficient vector and the dictionary.

Abstract: A method of reconstructing an image of an object, the method including: determining, by a plurality of sensors, a waveform based on the object, wherein the plurality of sensors view the object from a plurality of directions; determining, by a pre-processing module, a plurality of measurements of the object using the waveform, wherein the plurality of measurements are arranged in a vector form; determining, by an option module, a sampling matrix, a dictionary, and a noise factor, wherein the sampling matrix represents a geometric arrangement of the plurality of sensors, and the dictionary is pre-selected by the option module; estimating, by an estimation module, a coefficient vector using the measurements, the sampling matrix, and the noise factor; and reconstructing, by a reconstruction module, the image, using the coefficient vector and the dictionary.

Abstract: Embodiments of the present invention relate generally to receivers. A frequency modulated (FM) receiver includes an equalizer control unit coupled to receive at least one FM signal quality indicator and provide a control signal based on the FM signal quality indicator. An adaptive equalizer coupled to receive the control signal from the equalizer control unit and an FM signal and provide a filtered FM signal corresponding to the received FM signal. Coefficients of the adaptive equalizer are reset in response to the control signal. Another embodiment relates to a method for processing a frequency modulated (FM) signal. An FM signal is received. At least one FM signal quality indicator is used to provide a control signal. Based on the control signal, the received FM signal is filtered using one of an adaptive filter and a static filter to provide a filtered FM signal.

Abstract: A noise blanker (40, 106) monitors and removes noise from a sampled signal by adaptive filtering (98, 150) the sampled signal to generate trained adaptive filter prediction coefficients. The sampled signal is provided as an output signal when the noise blanker is in a training mode. A noise monitor (34, 154) detects whether noise contained within the sampled signal exceeds a predetermined threshold and provides a control signal in response to the detecting. The noise blanker is placed in a prediction mode for a predetermined amount of time in response to asserting the control signal. A prediction output signal is generated using a plurality of prediction coefficients as an all-pole filter. The prediction output signal has minimal noise content.

Abstract: A method for stopping on a radio station includes calculating a radio signal quality (205) using a multipath echo indicator and determining if the radio signal quality is greater than a predetermined signal quality threshold (210). A zero crossings indicator of a demodulated signal may be used (225) to reduce a false alarm rate. An apparatus includes an antenna (105), a local oscillator (110) coupled to the antenna, an analog-to-digital converter circuit (115) coupled to the local oscillator, a demodulator circuit (120) coupled to the analog-to-digital converter circuit, a signal strength determining circuit (125) coupled to the analog-to-digital converter circuit, a logarithmic circuit (150) coupled to the signal strength determining circuit, a multipath echo bandpass filter (155) coupled to the logarithmic circuit, and a stop-on-station circuit (145) coupled to the demodulator circuit, the multipath echo bandpass filter, and the logarithmic circuit.

Abstract: A noise blanker (40, 106) monitors and removes noise from a sampled signal by adaptive filtering (98, 150) the sampled signal to generate trained adaptive filter prediction coefficients. The sampled signal is provided as an output signal when the noise blanker is in a training mode. A noise monitor (34, 154) detects whether noise contained within the sampled signal exceeds a predetermined threshold and provides a control signal in response to the detecting. The noise blanker is placed in a prediction mode for a predetermined amount of time in response to asserting the control signal. A prediction output signal is generated using a plurality of prediction coefficients as an all-pole filter. The prediction output signal has minimal noise content.

Abstract: A method for stopping on a radio station includes calculating a radio signal quality (205) using a multipath echo indicator and determining if the radio signal quality is greater than a predetermined signal quality threshold (210). A zero crossings indicator of a demodulated signal may be used (225) to reduce a false alarm rate. An apparatus includes an antenna (105), a local oscillator (110) coupled to the antenna, an analog-to-digital converter circuit (115) coupled to the local oscillator, a demodulator circuit (120) coupled to the analog-to-digital converter circuit, a signal strength determining circuit (125) coupled to the analog-to-digital converter circuit, a logarithmic circuit (150) coupled to the signal strength determining circuit, a multipath echo bandpass filter (155) coupled to the logarithmic circuit, and a stop-on-station circuit (145) coupled to the demodulator circuit, the multipath echo bandpass filter, and the logarithmic circuit.

Abstract: A digital FM demodulator employs a baseband phase lock loop (BBPLL), which is particularly effective for long range reception, for combining and demodulating a pair of signals represented by the mathematical expression A(t)ej&thgr;(t) to result in an approximation of d&thgr;/dt. This approximation is then subjected to an inverse of the linear approximation of the frequency response of the BBPLL that produces a very accurate &thgr;. This is conveniently achieved with a IIR filter whose transfer function happens to be the same as the inverse of the linear approximation of the frequency response of the BBPLL. The derivative is then taken of &thgr; to produce a very accurate d&thgr;/dt, the desired result for the output of an FM demodulator. To aid operation of the BBPLL, the incoming digital intermediate frequency is upsampled by a combination of sample and hold and FIR filtering prior to being processed by the BBPLL.

Abstract: A digital FM demodulator employs a baseband phase lock loop (BBPLL), which is particularly effective for long range reception, for combining and demodulating a pair of signals represented by the mathematical expression A(t)ej&thgr;(t) to result in an approximation of d&thgr;/dt. This approximation is then subjected to an inverse of the linear approximation of the frequency response of the BBPLL that produces a very accurate &thgr;. This is conveniently achieved with a IIR filter whose transfer function happens to be the same as the inverse of the linear approximation of the frequency response of the BBPLL. The derivative is then taken of &thgr; to produce a very accurate d&thgr;/dt, the desired result for the output of an FM demodulator. To aid operation of the BBPLL, the incoming digital intermediate frequency is upsampled by a combination of sample and hold and FIR filtering prior to being processed by the BBPLL.