G01S13/90

Method and apparatus for generating non-linear frequency modulation signal in real time and computer storage medium

A method and apparatus for generating a NLFM signal in real time, and a computer storage medium are disclosed, including: determining a signal parameter of a signal according to a system parameter, the signal parameter includes: a signal bandwidth, a signal pulse width and a PSLR; determining a power spectrum density function according to PSLR; calculating the power spectrum density function to obtain a group delay vector; calculating a frequency axial vector according to a system sampling rate; calculating a time axial vector according to the signal pulse width; performing linear interpolation calculation on the group delay vector to obtain an instantaneous frequency vector; integrating the instantaneous frequency vector to obtain a phase vector; determining a signal time domain discrete vector; and generating a digital signal according to the signal time domain discrete vector, and performing digital-to-analog conversion on the digital signal to obtain the NLFM signal.

Method and apparatus for space-variance correction imaging of bistatic SAR, device and storage medium

A method for space-variance correction imaging of BiSAR includes: motion parameters corresponding to a target point in an equivalent monostatic mode are calculated using a first motion trajectory, a second motion trajectory and an imaging parameter for focusing a radar echo signal, the target point at least including a center point of an imaging scene; azimuth Doppler center bias correction is performed on the radar echo signal by using the motion parameters corresponding to the center point; uniform and residual range cell migration correction is performed on a corrected signal, range blocking is performed, and range space-variance phase errors are corrected block by block; azimuth blocking is performed, and a corresponding number of filters are constructed for filtering processing; and inverse Doppler center bias correction is further performed to obtain a final imaging result graph.

HUMAN-PERCEPTIBLE AND MACHINE-READABLE SHAPE GENERATION AND CLASSIFICATION OF HIDDEN OBJECTS
20220373673 · 2022-11-24 ·

System and methodology are disclosed for approximating traditional SAR imaging on mobile mmWave devices. The presently disclosed technology enables human-perceptible and machine-readable shape generation and classification of hidden objects on mobile mmWave devices. The resulting system and corresponding methodology are capable of imaging through obstructions, like clothing, and under low visibility conditions. To this end, the presently disclosed technology incorporates a machine-learning model to recover the high-spatial frequencies in the object to reconstruct an accurate 2D shape and predict its 3D features and category. The technology is disclosed in particular for security applications, but the broader model disclosed is adaptable to different applications, even with limited training samples.

METHOD AND DEVICE FOR IMPROVED RANGE TRACKING FOR INVERSE SYNTHETIC APERTURE RADAR
20220373674 · 2022-11-24 · ·

The present application presents various techniques for improving the performance of range tracking motion compensation method for high resolution radar imaging. Three improved techniques are described herein: improved cross-correlation alignment through updates to the reference range profile to follow the target's changing illumination angle; improved cross-correlation alignment through local peak boosting; and, improved polynomial smoothing through subdivision into multiple windows.

Fine-motion virtual-reality or augmented-reality control using radar
11592909 · 2023-02-28 · ·

This document describes techniques for fine-motion virtual-reality or augmented-reality control using radar. These techniques enable small motions and displacements to be tracked, even in the millimeter or sub-millimeter scale, for user control actions even when those actions are small, fast, or obscured due to darkness or varying light. Further, these techniques enable fine resolution and real-time control, unlike conventional RF-tracking or optical-tracking techniques.

Fine-motion virtual-reality or augmented-reality control using radar
11592909 · 2023-02-28 · ·

This document describes techniques for fine-motion virtual-reality or augmented-reality control using radar. These techniques enable small motions and displacements to be tracked, even in the millimeter or sub-millimeter scale, for user control actions even when those actions are small, fast, or obscured due to darkness or varying light. Further, these techniques enable fine resolution and real-time control, unlike conventional RF-tracking or optical-tracking techniques.

Synthetic aperture radar imaging apparatus and methods
11506778 · 2022-11-22 · ·

A synthetic aperture radar (SAR) is operable in an interrogation mode and in an imaging mode, the imaging mode entered in response to determining a response to interrogation pulses have been received from a ground terminal and position information specifying a ground location has been received from the ground terminal. A ground terminal is operable to receive interrogation pulses transmitted by a SAR, transmit responses, and transmit position information to cause the SAR to enter a imaging mode. The ground terminal receives first and subsequent pulses from the SAR where subsequent pulses include backscatter and are encoded. The ground terminal generates a range line by range compression. If the SAR is a multi-band SAR the transmitted pulses can be in two or more frequency bands, and subsequent pulses in one frequency band can include encoded returns from pulses transmitted in a different frequency band.

Synthetic aperture radar imaging apparatus and methods
11506778 · 2022-11-22 · ·

A synthetic aperture radar (SAR) is operable in an interrogation mode and in an imaging mode, the imaging mode entered in response to determining a response to interrogation pulses have been received from a ground terminal and position information specifying a ground location has been received from the ground terminal. A ground terminal is operable to receive interrogation pulses transmitted by a SAR, transmit responses, and transmit position information to cause the SAR to enter a imaging mode. The ground terminal receives first and subsequent pulses from the SAR where subsequent pulses include backscatter and are encoded. The ground terminal generates a range line by range compression. If the SAR is a multi-band SAR the transmitted pulses can be in two or more frequency bands, and subsequent pulses in one frequency band can include encoded returns from pulses transmitted in a different frequency band.

OBJECT SENSING FROM A POTENTIALLY MOVING FRAME OF REFERENCE WITH VIRTUAL APERTURES FORMED FROM SPARSE ANTENNA ARRAYS

In some examples, a first plurality of independent waveforms can be generated and converted into a first plurality of independent transmitted radar signals transmitted towards a field of view using a transmitter array comprising a first plurality of transmitter antennas. Further, a second plurality of receive radar signals to the first plurality of independent transmitted radar signals can be received from the field of view using a receiver array comprising a second plurality of receiver antennas. The second plurality of receive radar signals can be combined to form a combined receive radar signal and a representation of one or more areas of interest in the field of view can be provided using the combined receive radar signal. One or more attributes of the one or more areas of interest can be rendered using the representation of the one or more areas of interest.

MARITIME SURVEILLANCE RADAR
20220365171 · 2022-11-17 ·

A maritime radar system is provided, comprising a transmitter, a receiver, and one or more processors arranged to provide range and azimuth discrimination of a detection area by performing a delay/Doppler analysis of the echo of a single beam transmitted by the transmitter and received by the receiver.