The disclosure relates to a method and a system for terahertz ISAR imaging. In the method, a chirp signal is transmitted to an imaging target moving at a preset speed and a terahertz ISAR echo signal is received. The terahertz ISAR echo signal is matched filtered in a fast time domain, baseband transformed in a slow time domain, corrected to eliminate a time domain zero offset, baseband transformed, discretized, interpolated, and two-dimensional inverse Fourier transformed to obtain a two-dimensional image of the imaging target.

A human body security check system based on millimeter wave holographic three-dimensional imaging, comprising a mechanical scanning mechanism, millimeter wave signal transceiver units, an image processing unit (7), and an alarm unit (9). The mechanical scanning mechanism is used for driving the millimeter wave signal transceiver units to simultaneously move horizontally and vertically relative to an individual to be checked (10); the millimeter wave signal transceiver units are used for transmitting millimeter wave signals to the individual to be checked (10) and receiving millimeter wave signals reflected by the individual to be checked (10); the image processing unit (7) is used for performing holographic three-dimensional imaging on the body of the individual to be checked (10) according to the reflected millimeter wave signals so as to obtain a three-dimensional image of the body; the alarm unit (9) is used for comparing the three-dimensional image of the body with a three-dimensional image of a secure body pre-stored in the alarm unit (9), and giving an alarm if the three-dimensional image of the body does not match the three-dimensional image of the secure body pre-stored in the alarm unit. The human body security check system is low in costs because electrical scanning is replaced with mechanical scanning, and features a simple structure, a short production period, high resolution, a short imaging time, and wide application. Also provided is a human body security check method based on millimeter wave holographic three-dimensional imaging.

A method and a system for detection and synthetic aperture (SA) imaging of a target are disclosed. The method may include illuminating a scene with a search signal transmitted from a moving platform, receiving a search return signal from a target present in the scene, and estimating, from the search return signal, the range and the angular location of the target. The method may also include generating an SA transmission signal and a local oscillator (LO) signal with a time delay therebetween based on the estimated range, and illuminating the scene with the SA transmission signal pointed along an imaging direction based on the estimated angular location of the target. The method may further include receiving an SA return signal from the target, mixing the SA return signal with the LO signal to generate SA signal data, and generating an SA image of the target from the SA signal data.

A radar anti-spoofing system for an autonomous vehicle includes a plurality of radar sensors that generate a plurality of input detection points representing radio frequency (RF) signals reflected from objects and a controller in electronic communication with the plurality of radar sensors. The one or more controllers execute instructions to determine a signal to noise ratio (SNR) distance ratio for the input detection points generated by the plurality of radar sensors, where a value of the SNR distance ratio is indicative of an object being a ghost vehicle. The one or more controllers also determine an effective particle number indicating a degree of particle degradation for the importance sampling for each variable that is part of the state variable. In response to determining the effective particle number is equal to or less than a predetermined threshold, the one or more controllers estimate a ghost position for the ghost vehicle.

The present invention relates to the technical field of synthetic aperture radar, and in particular to a ground-based interference synthetic aperture radar-based atmospheric phase compensation method. The present invention first uses the inverse fast Fourier transform algorithm to rapidly and effectively realize the focusing in the range and cross-range dimension. Then a triple threshold method which combines coherence coefficient, amplitude, and amplitude dispersion index is used to select reliable PS points. Finally, under a full consideration of the spatial correlation of the atmospheric phase, the atmospheric phase is estimated by using a two-dimensional-polynomial model. The present invention can rapidly and accurately estimate and compensate the atmospheric phase, is helpful in improving the accuracy of GB-InSAR real-time measurement, and valuable and universal in practical application.

Provided are a method and an apparatus for range ambiguity suppression based on orthogonal nonlinear frequency modulation (NLFM) waveforms. The method includes that: according to transmitted orthogonal NLFM signals, a waveform sequence of the transmitted signals corresponding to an obtained echo signal is determined; a set of range matched filters is constructed according to the waveform sequence and the orthogonal NLFM signals; range compression is performed on the echo signal by using the set of range matched filters to obtain range-compressed data; and synthetic aperture radar (SAR) imaging is performed according to the range-compressed data, to obtain an imaging result, and the imaging result is outputted. A non-transitory computer-readable storage medium is also provided.

The present disclosure provides a method for surface wear inspection using millimeter wave radar. The system initially receives a plurality of uncompressed raw Synthetic Aperture Radar (SAR) images. Further, a plurality of reconstructed SAR images are generated based on the plurality of uncompressed raw SAR images using a variable focusing based Range Doppler Algorithm (RDA). Further, a master image and a slave image are selected from the reconstructed SAR images and corresponding anchor points are assigned. Further a plurality of fine level and coarse level shift coordinates are computed based on the corresponding anchor points. Further, a net shift value is computed based on the plurality of fine level and coarse level shift coordinates. The master and the slave images are aligned based on the net shift value and the interferogram is generated. The interferogram is further analyzed to profile the corresponding deformation pertaining to the surface under test.

The disclosure relates to a method and a system for terahertz ISAR imaging. In the method, a chirp signal is transmitted to an imaging target moving at a preset speed and a terahertz ISAR echo signal is received. The terahertz ISAR echo signal is matched filtered in a fast time domain, baseband transformed in a slow time domain, corrected to eliminate a time domain zero offset, baseband transformed, discretized, interpolated, and two-dimensional inverse Fourier transformed to obtain a two-dimensional image of the imaging target.

A method for synthetic aperture radar signal processing includes storing signal responses of a radar signal in a memory buffer, wherein the stored signal responses are represented by a two-dimensional signal in an azimuth dimension and a range dimension. The method further includes frequency filtering the two-dimensional signal in the azimuth dimension. In addition, the method includes applying a Fourier transformation to the frequency filtered signal in the range dimension. The method further includes generating a synthetic aperture radar image based on the Fourier transformed frequency filtered signal.

A millimeter-wave three-dimensional holographic imaging method and system. The method comprises: transmitting a continuous frequency wave to a measured human body, and receiving an echo signal reflected back; performing Fourier transform, phase compensation, inverse Fourier transform, and non-uniform sampling to uniform sampling interpolation; and projecting three-dimensional echo data to obtain two-dimensional reconstruction data, and generating a two-dimensional reconstructed image.