This paper investigates a novel approach based on the deramping technique for squinted sliding spotlight Synthetic Aperture Radar (SAR) imaging to resolve the azimuth spectrum aliasing problem. First of all, the prope...This paper investigates a novel approach based on the deramping technique for squinted sliding spotlight Synthetic Aperture Radar (SAR) imaging to resolve the azimuth spectrum aliasing problem. First of all, the properties of the azimuth spectrum and the squint angle impacts on the azimuth spectrum aliasing problem are analyzed. Based on the analysis result, an operation of filtering is added to the azimuth preprocessing step of traditional Two-Step Focusing Approach (TSPA) to resolve the azimuth folding problem and remove the influence of the squint angle on the azimuth spectrum aliasing problem. Then, a modified Range Migration Algorithm (RMA) is performed to obtain the precise focused image. Furthermore, the focused SAR image folding problem of traditional TSPA is illuminated in this paper. An azimuth post-processing step is proposed to unfold the aliased SAR image. Simulation experiment results prove that the proposed approach can solve the spectrum aliasing problem and process squinted sliding spotlight data efficiently.展开更多
This paper summarizes our research work on optoelectronic devices with nanostructures. It was indi- cated that by manipulating so called ＂general energybands＂ of fundamental particles or quasi-particles, such as pho...This paper summarizes our research work on optoelectronic devices with nanostructures. It was indi- cated that by manipulating so called ＂general energybands＂ of fundamental particles or quasi-particles, such as photon, phonon, and surface plasmon polariton （SPP）, novel optoelectronic characteristics can be obtained, which results in a series of new functional devices. A silicon based optical switch with an extremely broadband of 24 nm and an ultra-compact （8 μm -17.6μm） footprint was demonstrated with a photonic crystal slow light waveguides. By proposing a nanobeam based hereto optomechanical crystal, a high phonon frequency of 5.66 GHz was realized experimentally. Also, we observed and verified a novel effect of two-surface-plasmon-absorption （TSPA）, and realized diffraction-limit-overcoming photolithography with resolution of-1/11 of the exposure wavelength.展开更多
文摘This paper investigates a novel approach based on the deramping technique for squinted sliding spotlight Synthetic Aperture Radar (SAR) imaging to resolve the azimuth spectrum aliasing problem. First of all, the properties of the azimuth spectrum and the squint angle impacts on the azimuth spectrum aliasing problem are analyzed. Based on the analysis result, an operation of filtering is added to the azimuth preprocessing step of traditional Two-Step Focusing Approach (TSPA) to resolve the azimuth folding problem and remove the influence of the squint angle on the azimuth spectrum aliasing problem. Then, a modified Range Migration Algorithm (RMA) is performed to obtain the precise focused image. Furthermore, the focused SAR image folding problem of traditional TSPA is illuminated in this paper. An azimuth post-processing step is proposed to unfold the aliased SAR image. Simulation experiment results prove that the proposed approach can solve the spectrum aliasing problem and process squinted sliding spotlight data efficiently.
基金This work was supported by the National Basic Research Program of China （No. 2013CB328704 and 2013CBA01704）, the National Natural Science Foundation of China （Grant No. 61307068）.
文摘This paper summarizes our research work on optoelectronic devices with nanostructures. It was indi- cated that by manipulating so called ＂general energybands＂ of fundamental particles or quasi-particles, such as photon, phonon, and surface plasmon polariton （SPP）, novel optoelectronic characteristics can be obtained, which results in a series of new functional devices. A silicon based optical switch with an extremely broadband of 24 nm and an ultra-compact （8 μm -17.6μm） footprint was demonstrated with a photonic crystal slow light waveguides. By proposing a nanobeam based hereto optomechanical crystal, a high phonon frequency of 5.66 GHz was realized experimentally. Also, we observed and verified a novel effect of two-surface-plasmon-absorption （TSPA）, and realized diffraction-limit-overcoming photolithography with resolution of-1/11 of the exposure wavelength.
