36results about How to "Improve azimuth resolution" patented technology

The invention relates to a re-focusing and imaging method for an on-board radar without any hi-precision motion compensation system, which comprises two procedures: (1) SAR initial compound image creation based on de-gradient processing; (2) Doppler signal phase error is measured based on improved PGA arithmetic, and compound image re-focusing for phase compensation is carried out. The second procedure comprises the following steps: the compound images are input; the center of the target with the most intensive point goes through cyclic movement; a window is added; Fourier transformation is done for orientation; estimation is made on the phase error; the phase is corrected; inverse Fourier transformation is done to return the compound image area. The invention allows to get on-board L-SARre-focused images with resolution of orientation obviously improved only by original signal data without any hi-accuracy on-board platform movement compensation system to provide the info on movementstate of an airplane; and the higher the contrast in the images, the better the focusing effect will be. As the SAR wavelength of L wave section is longer and penetrating, the invention can play highrole in military reconnaissance and monitoring any disaster in civil application.

The invention discloses a scanning radar forward-looking imaging method based on spatial embedded mapping. Specifically, on the basis of echo range pulse compression and range walking correction, the problem of improving azimuth resolution is transformed into a matrix solution problem; Value decomposition theory, analyze the singular value distribution of the antenna measurement matrix, determine the order of the space embedding matrix and generate the space embedding matrix under the premise of retaining the information of the antenna measurement matrix to the greatest extent; use the space embedding matrix to extract the information of the antenna measurement matrix, Reconstruct the antenna measurement matrix and the echo signal, reduce the order of the matrix, increase the uncorrelated characteristics of the matrix, and improve the ill-conditionedness of the antenna measurement matrix; according to the data model of the spatial embedding mapping, reduce the order of the antenna measurement matrix, thereby reducing the complexity of the operation degree; use the principle of least squares to solve the scattering coefficient of the target, and realize high-resolution and fast imaging of the target azimuth.

The invention discloses a mixed regularization azimuth super-resolution imaging method, which is applied in the field of radar imaging and aims at traditional L 2 Regularized imaging method has low resolution, traditional L 1 For the problem of poor anti-noise performance of the regularized imaging method, the present invention first establishes a convolution-like model of scanning radar azimuth echo; then, through L 2 The regularization method preprocesses the echo signal; finally, based on the preprocessing result, L 1 The norm characterizes the target sparse prior information to reconstruct the target function, and the method of iteratively reweighting the norm is used to solve the target function. The innovation of the present invention lies in: combining L 1 Regular term and L 2 The advantages of the regular term, use L 2 The norm weakens the influence of noise and avoids the noise being amplified in the iterative process, and then uses L 1 The sparse nature of the norm improves the azimuth resolution of imaging. This method is different from the conventional L 2 Compared with the regularization method, the azimuth resolution is improved, and compared with the traditional L 1 Compared with the regularization method, the noise is well suppressed.

The invention discloses a time-division ground-based MIMO landslide radar imaging method based on IFFT and mixed-matching tracking, which is used to solve the problems of large number of antennas and high data processing complexity in the existing imaging methods in the field of landslide monitoring, and aims at the false detection of multi-target imaging. The shadow point problem introduces a mixed-matching tracking algorithm, which greatly improves the imaging quality. The realization steps are: constructing an equivalent random sparse transceiver array; establishing an echo signal acquisition model; compressing processing in the range direction; compressing processing in the azimuth direction; completing two-dimensional target high-resolution imaging. The invention has the following advantages: the number of arrays is reduced, the cost of hardware is reduced; the complexity of data processing is reduced; and the resolution of distance direction and azimuth direction is improved.

The present invention provides a Ku-band phased array water surface target detection system with adaptive beam stabilization. The radar array antenna array included in the present invention is connected with the T / R component through the traveling wave coupling feeder line, and the T / R component is connected with a wave control The extension is connected to the calibration front end, the wave control extension is connected to the servo extension and the display control extension, the calibration front is connected to the T / R component and the traveling wave coupling feeder, the calibration front is connected to the transmission channel and the reception channel, the transmission channel is connected to the reception channel, and the reception channel It is connected with the signal processing extension, the signal processing extension is respectively connected with the wave control extension, the servo extension and the display control extension, the display control extension is connected with the wave control extension, and the modular power supply provides power for the detection system. The detection system of the present invention is small in size, can perceive the attitude information of the carrier in real time, and has stable self-adaptive beams.

The invention provides a synthetic aperture laser radar imaging method, instrument and system. The method includes: transmitting laser signals through an optical telescope arranged on the synthetic aperture lidar, and simultaneously receiving echo signals by using at least two optical telescopes arranged on the synthetic aperture lidar along the azimuth direction; The echo signal is subjected to along-track interference processing to obtain the along-track differential interferometric phase; the slant-range velocity error is obtained through the along-track differential interferometric phase, and the motion error caused by vibration is obtained by using the slant-range velocity error; The above motion error performs motion error compensation processing on the echo signals received by the at least two optical telescopes to obtain at least two azimuth image data to be compressed; perform Doppler signal coherent synthesis on the azimuth image data to be compressed , to complete the azimuth compression processing of the imaging.

The invention discloses a direction finding method based on time sequence packet filtering and amplitude difference gradual approximation, which comprises four steps of grouping of long and short pulses, selection of filter coefficients, determination of a pulse group of the current target and determination of a target direction. According to the direction finding method based on the time sequence packet filtering and amplitude difference gradual approximation strategy, on the basis of the prior art, a single pulse group inside a CPI is subjected to regrouping filtering processing to reduce width restrictions on the CPI, the target detection direction resolution can be improved, and the detection target direction precision can be improved.

The invention relates to a regularization least square subspace crossing target direction finding method. According to the method, the Tikhonov regularization method and the least square subspace crossing algorithm are combined to process received signals of a shallow-sea sonar apparatus. On a basis of constructing a least square problem through the utilization of the subspace crossing principle, and then through the regularization method, optimal regularization factors are determined, so that detection and accurate positioning of shallow-sea targets are finally realized. According to the regularization least square subspace crossing target direction finding method of the invention, the Tikhonov regularization method and the least square subspace crossing algorithm are combined for form a new direction finding algorithm. Compared with routine wave beam formation algorithms, the method is better in direction resolution performance and higher in accuracy degree, and the value calculating is stable.