Various embodiments include methods and systems having detection apparatus operable to cancel or reduce leakage signal originating from a source signal being generated and transmitted from a transmitter. A leakage cancellation signal can be generated digitally, converted to an analog signal, and then subtracted in the analog domain from a received signal to provide a leakage-reduced signal for use in detection and analysis of objects. A digital cancellation signal may be generated by generating a cancellation signal in the frequency domain and converting it to the time domain. Optionally, an estimate of a residual leakage signal can be generated and applied to reduce residual leakage remaining in the leakage-reduced signal. Additional apparatus, systems, and methods can be implemented in a variety of applications.

An ultrasonic diagnostic imaging for analyzing shear wave characteristics utilizes a background motion compensation subsystem which acts as a spatial filter of pulse-to-pulse autocorrelation phases over the ROI of tracking pulse vectors to compensate for background motion. The subsystem is configured to compute the sum of all lag-1 autocorrelations of tracking line ensemble data over the tracking ROI, for each PRI. The inventive technique does not significantly reduce sensitivity to shear waves, because the shear wave is spatially smaller than the ROI.

A method for evaluating an height of an object in the surrounding environment of a vehicle, using ultrasonic signals acquired by an ultrasonic sensor mounted on the vehicle. In a measurement cycle, a first ultrasonic signal is acquired as an edge reflection or as a directly traveling echo of an object. An expectation window is calculated for an associated interior-corner reflection. A second ultrasonic signal acquired in the expectation window is recognized as an interior-corner reflection associated with the first ultrasonic signal. The first and second ultrasonic signals are combined to form a signal group. A significance is determined for each ultrasonic signal. The signal group is assigned to a first or second echo group. The rates of the assignment to the first and to the second echo group are determined over a number of measurement cycles. An evaluation of the height is based on the first and second rates.

Various embodiments include methods and systems having detection apparatus operable to cancel or reduce leakage signal originating from a source signal being generated and transmitted from a transmitter. A leakage cancellation signal can be generated digitally, converted to an analog signal, and then subtracted in the analog domain from a received signal to provide a leakage-reduced signal for use in detection and analysis of objects. A digital cancellation signal may be generated by generating a cancellation signal in the frequency domain and converting it to the time domain. Optionally, an estimate of a residual leakage signal can be generated and applied to reduce residual leakage remaining in the leakage-reduced signal. Additional apparatus, systems, and methods can be implemented in a variety of applications.

A method for evaluating an height of an object in the surrounding environment of a vehicle, using ultrasonic signals acquired by an ultrasonic sensor mounted on the vehicle. In a measurement cycle, a first ultrasonic signal is acquired as an edge reflection or as a directly traveling echo of an object. An expectation window is calculated for an associated interior-corner reflection. A second ultrasonic signal acquired in the expectation window is recognized as an interior-corner reflection associated with the first ultrasonic signal. The first and second ultrasonic signals are combined to form a signal group. A significance is determined for each ultrasonic signal. The signal group is assigned to a first or second echo group. The rates of the assignment to the first and to the second echo group are determined over a number of measurement cycles. An evaluation of the height is based on the first and second rates.

Various embodiments include methods and systems having a frequency-modulated continuous wave radar operable to compensate a return signal for nonlinearity in the associated radar signal that is transmitted. The radar signal can be mixed with a delayed version of the radar signal such that the mixed signal can be used to generate an estimate of the nonlinearity. The estimate can be used to compensate the return signal from an object that reflects the associated transmitted radar signal. Additional apparatus, systems, and methods can be implemented in a variety of applications.

Various embodiments include methods and systems having detection apparatus operable to cancel or reduce leakage signal originating from a source signal being generated and transmitted from a transmitter. A leakage cancellation signal can be generated digitally, converted to an analog signal, and then subtracted in the analog domain from a received signal to provide a leakage-reduced signal for use in detection and analysis of objects. A digital cancellation signal may be generated by generating a cancellation signal in the frequency domain and converting it to the time domain. Optionally, an estimate of a residual leakage signal can be generated and applied to reduce residual leakage remaining in the leakage-reduced signal. Additional apparatus, systems, and methods can be implemented in a variety of applications.

An imaging system that utilizes deterministic bit sequences modulated onto an in-phase component of a carrier frequency and continuously transmitted via a transducer and received for imaging a medium and/or environment is provided. The received signal is demodulated by an in-phase demodulator and a quadrature demodulator and the demodulated components are processed to provide a spatial mapping of a medium or environment being imaged.

A method for performing acoustic imaging and measurements may include generating a nonlinear frequency modulation (NLFM) chirp waveform based on a frequency response of at least one transducer. The method may further include generating an apodized signal by applying a window function to the NLFM chirp waveform. The method may further include exciting the at least one transducer with the apodized signal. The method may further include compressing received signals by using one or more matched filters.

An ultrasonic diagnostic imaging for analyzing shear wave characteristics utilizes a background motion compensation subsystem which acts as a spatial filter of pulse-to-pulse autocorrelation phases over the ROI of tracking pulse vectors to compensate for background motion. The subsystem is configured to compute the sum of all lag-1 autocorrelations of tracking line ensemble data over the tracking ROI, for each PRI. The inventive technique does not significantly reduce sensitivity to shear waves, because the shear wave is spatially smaller than the ROI.