Wavelet-fractal based SAR （synthetic aperture radar） image processing is one of the advanced technologies in image processing. The main concept of analysis is that after wavelet transformation, multifractal spectrum...Wavelet-fractal based SAR （synthetic aperture radar） image processing is one of the advanced technologies in image processing. The main concept of analysis is that after wavelet transformation, multifractal spectrum of the signal is different from that of noise. This difference is used to alleviate the noise produced by SAR image.The method to denoise SAR image using the process based on wavelet-fractai analysis is discussed in detail. Essentially, the present method focuses on adjusting the Hoelder exponent α of multifractal spectrum. After simulation, α should be adjusted to 1.72-1.73. The more the value of α exceeds 1.73, the less distinctive the edges of SAR image become. According to the authors denoising is optimal at α=1.72-1.73. In other words, when α =1.72-1.73, a smooth and denoised SAR image is produced.展开更多
The calculation method about infrared multi-sites passive system location is introduced based on the principle of the weighted least square method, and the variance matrix of estimated error is offered. Through deduct...The calculation method about infrared multi-sites passive system location is introduced based on the principle of the weighted least square method, and the variance matrix of estimated error is offered. Through deduction, it can be found out that treated appraise precision can be directly analyzed and deduced without carrying out real measure and reaching estimation value. The simulation result shows that the system performance based on the weighted least square method is much better than the traditional passive location method, and it can be also used for reference to the research of the location algorithm of similar system.展开更多
The quantum key distribution(QKD) has been entering the practical application era. Subsequently, hybrid quantum private communication with discrete-variable signals, continuous-variable signals, and classic optical si...The quantum key distribution(QKD) has been entering the practical application era. Subsequently, hybrid quantum private communication with discrete-variable signals, continuous-variable signals, and classic optical signals becomes inevitable in the practical scenario. In this paper, we experimentally investigated the mutual effects between the discrete-variable QKD(DVQKD) and the continuous-variable QKD(CVQKD) via a fiber channel. The experimental results show that the DVQKD will be influenced by the continuous-variable quantum signals and classic optical signals, while the CVQKD is not sensitive to the discrete-variable quantum signals.展开更多
文摘Wavelet-fractal based SAR （synthetic aperture radar） image processing is one of the advanced technologies in image processing. The main concept of analysis is that after wavelet transformation, multifractal spectrum of the signal is different from that of noise. This difference is used to alleviate the noise produced by SAR image.The method to denoise SAR image using the process based on wavelet-fractai analysis is discussed in detail. Essentially, the present method focuses on adjusting the Hoelder exponent α of multifractal spectrum. After simulation, α should be adjusted to 1.72-1.73. The more the value of α exceeds 1.73, the less distinctive the edges of SAR image become. According to the authors denoising is optimal at α=1.72-1.73. In other words, when α =1.72-1.73, a smooth and denoised SAR image is produced.
基金Supported by the Research Fund for the Department of Science and Technology of Xi'an (No.GG9907)
文摘The calculation method about infrared multi-sites passive system location is introduced based on the principle of the weighted least square method, and the variance matrix of estimated error is offered. Through deduction, it can be found out that treated appraise precision can be directly analyzed and deduced without carrying out real measure and reaching estimation value. The simulation result shows that the system performance based on the weighted least square method is much better than the traditional passive location method, and it can be also used for reference to the research of the location algorithm of similar system.
基金supported by the National Natural Science Foundation of China(Grant Nos.61170228,61332019 and 61102053)China Postdoctoral Science Foundation(Grant No.2013M540365)+1 种基金the Natural Science Special Fund of Department of Education in Shaanxi(Grant No.12JK0497)Shaanxi Natural Science Foundation(Grant No.2013JM8036)
文摘The quantum key distribution(QKD) has been entering the practical application era. Subsequently, hybrid quantum private communication with discrete-variable signals, continuous-variable signals, and classic optical signals becomes inevitable in the practical scenario. In this paper, we experimentally investigated the mutual effects between the discrete-variable QKD(DVQKD) and the continuous-variable QKD(CVQKD) via a fiber channel. The experimental results show that the DVQKD will be influenced by the continuous-variable quantum signals and classic optical signals, while the CVQKD is not sensitive to the discrete-variable quantum signals.
