This invention provides millimeter wave holographic 3D imaging detection system, which comprises: a transmitting antenna configured to transmit a millimeter wave transmitting signal to an object to be detected; a receiving antenna configured to receive an echo signal from the object to be detected; a millimeter wave transceiving module configured to generate the millimeter wave transmitting signal transmitted to the object to be detected and receive and process the echo signal from the receiving antenna; a scanning device configured to support the millimeter wave transceiving module, the transmitting antenna and the receiving antenna, and move the millimeter transceiving module, the transmitting antenna and the receiving antenna along a preset track, so as to scan the object to be detected with millimeter waves; a data gathering and processing module configured to gather and process the echo signal output from the millimeter wave transceiving module to generate a 3D image of the object to be detected; and an image display unit configured to display the 3D image generated by the data gathering and processing module. Besides, this invention also provides a method of millimeter wave holographic 3D imaging detection on an object to be detected using the above system thereof. The technical solution of this invention has the advantages of simple structure, high resolution, short imaging time, and larger field of view.

A method according to the present invention comprises the steps of: dividing SAR raw data into one or more sub-aperture data by a predetermined number in an azimuth direction; performing a spectral length extension FFT on the sub-aperture data in the azimuth direction; multiplying the sub-aperture data by a chirp scaling function; performing a range FFT on the sub-aperture data; performing range compression, SRC, and a bulk RCMC on the sub-aperture data; performing an inverse chirp-z transform on the sub-aperture data in a range direction; multiplying the divided sub-aperture data by a predetermined first function; performing an IFFT on the sub-aperture data in the azimuth direction; recombining the sub-aperture data; multiplying the recombined data by a second function and deramping same; performing an azimuth FFT on the recombined data; performing an azimuth IFFT on the recombined data; multiplying the recombined data by a third function and deramping same; performing the azimuth FFT on the recombined data; performing azimuth compression by multiplying the recombined data by a fourth function; performing an azimuth inverse chirp-z transform on the recombined data; and multiplying the recombined data by a fifth function for phase preservation.

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.

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 preprocessing technique for synthetic radar images. An embodiment of a method for preprocessing synthetic aperture radar images includes: receiving range-compressed radar data generated from raw radar image data on-board a satellite or an airborne vehicle; generating a preliminary SAR image by performing a pre-focusing on the range-compressed radar data; extracting image subsectors from the preliminary SAR image; transmitting the extracted image subsectors to an on-ground portion; reconstructing the range-compressed radar data pertaining to the extracted image subsectors; and making the range-compressed radar data pertaining to the extracted image subsectors available for a Nominal synthetic aperture radar processor, wherein the Nominal synthetic aperture radar processor is configured to generate a focused SAR image having a nominal value of image resolution that is higher than the resolution of the preliminary SAR image.

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.

A radar image processing device is provided for generating a radar image from a region of interest (ROI). The radar image processing device receives transmitted radar pulses and radar echoes reflected from the ROI at different positions along a path of a moving radar platform and stores computer-executable programs including a range compressor, a graph modeling generator, a signal aligner, a radar imaging generator and a focused image generator. The radar image processing device performs range compression on the radar echoes by deconvolving the transmitted radar pulses and a radar measurement to obtain frequency-domain signals, generate a graph model represented by sequential positions of the moving radar platform and a graph shift matrix computed using the frequency-domain signals, iteratively denoise and align the frequency-domain signals to obtained denoised data and time shifts by solving a graph-based optimization problem represented by the graph model, wherein the approximated time shifts compensate phase misalignments caused by perturbed positions of the moving radar platform, and perform radar imaging based on the denoised data and the estimated time shifts to generate focused radar images.

A method for increasing localization utilizing overlapped broadband pulses includes using a transform to convert broadband returns into wavelength based returns. The wavelength based returns are grouped into at least two wavelength group returns for each location having different focal diameters. Intra-return probabilities of object location are computed from the group returns. Inter-return probabilities are computed for overlapping regions of the pulse returns. A pixel grid is established for displaying the calculated object location probabilities. By further processing, the pixel grid can be refined to show finer details.

The present invention relates to the technical fields of optical imaging, microwave imaging, radar detection, sonar, ultrasonic imaging, and target detection, imaging identification and wireless communication based on media such as sound, light and electricity, and in particular, to a fast imaging method suitable for passive imaging and active imaging and application of the fast imaging method in the above fields. According to the method provided by the present invention, image field distribution corresponding to a target is achieved based on a lens imaging principle, in combination with an electromagnetic field theory, according to a target signal received by an antenna array, through the amplitude and phase weighting of a unit signal and by using an efficient parallel algorithm. The method provided by the present invention has the advantages of capability of being compatible with passive imaging and holographic imaging, good imaging effect, small operation amount, low hardware cost, high imaging speed and suitability for long-distance imaging, and can be widely applied in the fields of optical imaging, microwave imaging, radar detection, sonar, ultrasonic imaging, and target detection, imaging identification and wireless communication based on media such as sound, light and electricity.

A radar signal processing device includes: a forming unit to form beams by using reception signals; a compensation unit to compensate for a phase within a range frequency; a generation unit to generate an image of each beam by applying Fourier transform in an azimuth direction to the beams (with phases compensated; an identification unit to identify a position of a target object based on the image; a calculation unit to calculate power of each beam represented by the image of each beam at a position of the target object; a computing unit to compute an antenna gain of each beam at a position of the target object; and an angle measurement unit to measure angle on the target object by performing maximum likelihood estimation of comparing the power of each beam with the antenna gain of each beam at the position of the target object.