Entity

Time filter

Source Type

Sanyuan, China

A new technique for image fusion based on nonsubsampled shearlet transform (NSST) and improved pulse-coupled neural network (PCNN) is proposed. NSST, as a novel multiscale geometric analysis tool, can be optimally efficient in representing images and capturing the geometric features of multidimensional data. As a result, NSST is introduced into the area of image fusion to complete the decompositions of source images in any scale and any direction. Then the basic PCNN model is improved to be improved PCNN (IPCNN), which is more concise and more effective. IPCNN adopts the contrast of each pixel in images as the linking strength β, and the time matrix T of subimages can be obtained via the synchronous pulse-burst property. By using IPCNN, the fused subimages can be achieved. Finally, the final fused image can be obtained by using inverse NSST. The numerical experiments demonstrate that the new technique presented in this paper is competitive in the field of image fusion in terms of both fusion performance and computational efficiency. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE). Source


Li S.,Missile Institute | He J.,Telecommunication Engineering Institute | Feng Y.-Q.,Science Institute | Liu C.-Y.,Missile Institute | And 2 more authors.
Yuhang Xuebao/Journal of Astronautics | Year: 2012

A novel algorithm for ISAR (inverse synthetic aperture radar) jamming based on the micro-Doppler effect is proposed in the paper. A deception jamming method is presented first, in which the radar signals are repeated by the jammer with additional illusive micro-Doppler signatures after frequency-shift and amplitude-modulation. When receiving these jamming signals, the imaging radar will be confused. On the other hand, because of the additional modulation of the micro-Doppler effect to the radar echoes, the illusive micro-Doppler signals transmitted by the jammer can reduce the correlation between the range profiles, distort the initial phases, and form interference stripes along the azimuth direction. Therefore, another "smart" barrage jamming method is presented based on the micro-Doppler effect. The results of both simulated and measured data prove the effectiveness of these methods with relatively low jam-to-signal ratio. Source


Zhang W.,Missile Institute | Tong C.-M.,Missile Institute | Zhang Q.,Institute of Telecommunication Engineering
Yuhang Xuebao/Journal of Astronautics | Year: 2011

Under the configuration of single-channel, if the radius of the rotating blade is comparatively big, the relationship between the pulse repetition frequency (PRF) and the bandwidth of micro-Doppler will not follow the Shannon sampling theorem, i.e. sub-sampling occurs, which would lead to the phenomenon of micro-Doppler ambiguity. To solve this problem, a method for resolving the micro-Doppler ambiguity for targets with big rotating blades based on the dual-channel ATI technique is presented. The mathematical expressions of micro-Doppler frequency and the bandwidth of micro-Doppler are deduced in detail. The analysis indicates that the bandwidth of micro-Doppler under this configuration is modulated by using a sinusoidal function, which makes it much smaller than that of the single-channel situation, so the Shannon sampling theorem is satisfied and the whole time-frequency distribution without ambiguity can be gained. Finally, the simulation results are given to prove the validity of the presented method. Source


Zhang W.,Missile Institute | Tong C.,Nanjing Southeast University | Zhang Q.,Institute of Telecommunication Engineering | Zhang X.,Xian Communication Institute
2010 2nd IITA International Conference on Geoscience and Remote Sensing, IITA-GRS 2010 | Year: 2010

Aiming at extracting the time-varying micro-Doppler feature of the ground vibrating target within ground clutter environment, the method of micro-Doppler extraction based on dual-channel ATI technique is presented. The ATI technique is utilized to suppress the ground clutter, and preserve the interferometric signal of the vibrating target in the raw data domain, which is presented as a straight line along the azimuth direction. According to this feature, we can find out which range cell the signal locates at, and then by taking the time derivative of its phase, the micro-Doppler modulation can be obtained. Compared to the single-channel situation, there is no need to compensate for the Doppler shift caused by the radar's translation in advance, and we can obtain the micro-Doppler feature induced by the vibration in any direction, which will help to reduce the computation burden and improve the target detectability. Simulated results verify the validity of the proposed method. © 2010 IEEE. Source


Zhang W.,Missile Institute | Tong C.-M.,Missile Institute | Tong C.-M.,Nanjing Southeast University | Zhang Q.,Institute of Telecommunication Engineering
Tien Tzu Hsueh Pao/Acta Electronica Sinica | Year: 2011

Aiming at extracting the time-varying micro-Doppler feature of the vibrating target in ground clutter environment, the method of micro-Doppler extraction based on dual-channel ATI technique and Radon transform is presented. The ATI technique is utilized to suppress ground clutter and obtain the interferometric signal of the vibrating target, which is presented as a straight line along the azimuth direction in the range-compressed data domain. The Radon transform is utilized to detect the weak straight line and find out which range cell it locates at. And the mathematical expressions of micro-Doppler with different vibrating directions are derived and discussed in detail. Compared with the single-channel situation, it is no need to compensate for the Doppler shift caused by the radar's translation, and the target vibrating along the azimuth direction could be effectively detected, whose micro-Doppler presents remarkably nonperiodic feature. Simulated results verify the accuracy and availability of the proposed method. Source

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