Time filter

Source Type

The present disclosure provides a method for improving capability of resisting image noise of a co-phasing system of a dispersed fringe sensor. The method comprises the following steps: carrying out a coarse co-phasing adjustment by utilizing the dispersed fringe sensor until the coarse co-phasing is stabilized in a closed loop; collecting a two dimensional dispersed fringe image by the dispersed fringe sensor; superposing the dispersed fringe image along a dispersed direction so as to convert the two dimensional dispersed fringe image to a one dimensional image along an interferential direction; extracting peak values of the main peak, a left side lobe and a right side lobe of the one dimensional image along the interferential direction, and calculating corresponding piston error value of the image by carrying out a Left-subtracting-right LSR algorithm on these peak values.


Patent
CAS Institute of Electronics | Date: 2017-03-29

Disclosed is a real-time elevation DBF processing method, which includes: weighting and summing processing is performed on an intermediate frequency signal obtained from sampling made on each channel to obtain two channels of combined intermediate frequency signals; frequency mixing-based orthogonal demodulation is performed on signals in real number field of the two channels of combined intermediate frequency signals respectively; and cross summation is performed on two channels of demodulated intermediate frequency signals and resulting signals are low-pass filtered. Further disclosed is a real-time elevation DBF processing device.


Patent
CAS Institute of Electronics | Date: 2017-03-22

A method and device for generating a NLFM signal are provided, and the method includes: a power spectral density is determined according to a required PSLR; a frequency-time structures function of the signal is determined according to the power spectral density; a time-frequency structures function of the signal is determined according to the frequency-time structures function of the signal; the time-frequency structures function of the signal are integrated to obtain a phase, and discrete values of the signal using the obtained phase are calculated; and the series of digital signals are generated according to the discrete values of the signal, and digital-to-analog conversion is performed on the series of digital signals to obtain the NLFM signal.


A method and device for SAR imaging based on a NLFM signal are provided, and the method includes: performing range pulse compression on echo data according to a transmitted NLFM signal; compensating, according to a determined slant range error, the data subjected to the range pulse compression for a motion error at a reference distance to obtain compensated data; performing modified Stolt mapping on the compensated data; and compensating the data subjected to the modified Stolt mapping for a residual motion error and performing azimuth focusing on the data subjected to the compensation of the residual motion error so as to complete imaging of an NLFM signal.


Patent
CAS Institute of Electronics | Date: 2016-02-17

Disclosed is a method for improving quality of a ScanSAR image, and the method includes that range compression and RCMC are performed on each sub-swath of ScanSAR data; sub-aperture segmentation is performed on the ScanSAR data subjected to the range compression and the RCMC; aperture interpolation is performed on each sub-aperture data; and azimuth compression is performed on the sub-aperture data subjected to the aperture interpolation. Further disclosed is a device for improving quality of an ScanSAR image.


Patent
CAS Institute of Electronics | Date: 2016-03-02

Provided are a method and device for assessing damage in a disaster area, which can assess damage in the disaster area using a single post-event Very High Resolution (VHR) SAR image of the disaster area, and the method includes: a captured post-event Very High Resolution (VHR) Synthetic Aperture Radar (SAR) image of the disaster area is divided into at least one sub-image region; a Gray Level Co-occurrence Matrix (GLCM) corresponding to an ith sub-image region is acquired, and at least one texture feature value of the ith sub-image region is acquired according to the GLCM; texture feature value levels corresponding to respective texture feature values of the ith sub-image region are determined according to a preset ranking strategy; and a damage level of the ith sub-image region is acquired according to the texture feature value levels corresponding to respective texture feature values of the ith sub-image region and preset weights of respective texture feature values.


Patent
CAS Institute of Electronics | Date: 2016-04-26

The present disclosure provides an adaptive optical retina imaging apparatus and method. The adaptive optical retina imaging apparatus comprises an optical processing unit, an adaptive optical unit, a two-dimensional scanning unit and a primary aberration correcting unit, in which an imaging unit included in the optical processing unit is imaging based on the signal after high order aberration compensation and low order aberration compensation. By combining the adaptive optical technique, a con-focal scanning technique and the optical coherence tomography technique, two wave front sensors are utilized to detect wave front aberrations between the con-focal scanning optical path and the optical coherence tomography optical path and two wave front correctors are utilized to correct low order aberration and high order aberration of humans eyes, so as to implement low order aberration and high order aberration for the two optical paths and to implement imaging of humans eyes in a higher transverse resolution and a higher longitudinal resolution.


Patent
CAS Institute of Electronics | Date: 2016-04-27

Disclosed are a method and device for implementing Synthetic Aperture Radar (SAR) imaging, and the method include: an SAR signal is modulated and demodulated to obtain a demodulated echo signal; the demodulated echo signal is filtered to obtain a filtered echo signal; and imaging processing is performed on the filtered echo signal to obtain an imaging result.


Patent
CAS Institute of Electronics | Date: 2016-08-03

Provided are apparatuses and methods for super resolution imaging photolithography. An exemplary apparatus may includean illumination light generation device configured to generate illumination light for imaging a pattern included in a mask through the mask. The illumination light may include a high-frequency spatial spectrum such that a high-frequency evanescent wave component of spatial spectrum information for the light is converted to a low-frequency evanescent wave component after being transmitted through the mask pattern. For example, the illumination light generation device may be configured to form the illumination in accordance with a high numerical aperture (NA) illumination mode and/or a surface plasmon (SP)wave illumination mode.


A method and a system for detecting geological structure of an extraterrestrial solid planet by using a single-transmitter and multiple-receiver (STMR) radar are provided. According to the method, the detection of thickness distribution and geological structure of each geological layer on the extraterrestrial solid planet can be obtained by using a single-transmitter and multiple-receiver mode. Then information of the dielectric coefficients and the depth of the respective geological layer can be calculated accurately. Further, in the system, there are two detection channels, in which a first detection channel CH1 operates in a HF/VHF band for detecting geological structure of rocks on the extraterrestrial solid planet with a depth of detection over 100 meters and a depth resolution of several meters, and a second detection channel CH2 operates in a UHF band for detecting geological structure of regolith on the extraterrestrial solid planet with a depths of over 30 meters and a depth resolution less than 30cm. These two detection channels can cooperate with each other, ensuring accuracy and reliability of the detection.

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