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	Wavelet-Based Clustering Method for Geographical Flows Within a Linear Feature 期刊论文 OAI收割 TRANSACTIONS IN GIS, 2025, 卷号: 29, 期号: 4, 页码: e70079 作者: Gao, Meng; Pei, Tao; Jiang, Linfeng; Yan, Xiaorui; Fang, Zidong \| 收藏 \| 浏览/下载：1/0 \| 提交时间：2025/08/21 flow clustering geographical flow inhomogeneity of flow lengths spatial-frequency analysis wavelet transform
	Spatial Patterns and Scaling Distributions of Earthquake-Induced Landslides - A Case Study of Landslides in Watersheds Along Dujiangyan–Wenchuan Highway 期刊论文 OAI收割 Frontiers in Earth Science, 2021, 卷号: 9, 期号: 1, 页码: 1-12 作者: Xuemei Liu; 苏鹏程(Su PengCheng); Yong Li; Rui Xu; Jun Zhang \| 收藏 \| 浏览/下载：56/0 \| 提交时间：2022/03/25 Earthquake Landslide Hot Spot Analysis Frequency Curve Scaling Distribution Spatial Pattern
	Adjustment Strategy for Inclination Moire Fringes in Lithography by Spatial Frequency Decomposition 期刊论文 OAI收割 IEEE PHOTONICS TECHNOLOGY LETTERS, 2015, 卷号: 27, 期号: 4 作者: Zhu, Jiangping; Hu, Song; Su, Xianyu; You, Zhisheng 收藏 \| 浏览/下载：53/0 \| 提交时间：2015/07/10 Proximity lithography mask-wafer alignment phase analysis spatial frequency
	Comparison and simulation of subpixel imaging modes for linear CCD (EI CONFERENCE) 会议论文 OAI收割 2012 3rd International Conference on Information Technology for Manufacturing Systems, ITMS 2012, September 8, 2012 - September 9, 2012, Qingdao, China 作者: Li Y. 收藏 \| 浏览/下载：67/0 \| 提交时间：2013/03/25 Subpixel technique of linear CCD is effective to enhance the spatial resolution without increasing the focal length of optics and reducing the pixel size. To compare image quality of two main subpixel imaging modes quincunx sampling and four-point sampling a method to quantitatively evaluate image quality of subpixel based on MTF was proposed. The MTF of quincunx and four-point sampling modes were derived. Analytical results shows that theoretical limiting resolution of quincunx sampling and four-point sampling is improved to 1.4 and 1.86 times respectively and MTF values at Nyquist frequency of two modes are increased by 0.1106 and 0.1679 respectively. MTFA in (0 0.5) of two subpixel imaging modes were calculated and results illustrates that four-point sampling offers much more improvement with image quality than quincunx sampling at the cost of double amount of data. A model for simulating subpixel imaging using Matlab was established and simulation results of spoke target verify the theoretical analysis. (2012) Trans Tech Publications Switzerland.
	Evaluation of the operating range for ground-based infrared imaging tracking system (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China 作者: Zhang Z.-D. 收藏 \| 浏览/下载：65/0 \| 提交时间：2013/03/25 Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications on the other which should be calculated calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors without considering the effect of the background radiation. By improving of the traditional method including atmospheric attenuation a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end the dispersion of the image and the effect of image dispersion are not considered in the traditional method an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
	Design of high-resolution fourier transform lens (EI CONFERENCE) 会议论文 OAI收割 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China 作者: Zhang L.; Zhang L. 收藏 \| 浏览/下载：52/0 \| 提交时间：2013/03/25 With the development of optical information processing high-resolution Fourier transform lens has often been used in holographic data storage system spatial filtering and observation of particles. This paper studies the optical design method of high-resolution Fourier transform optical lenses system which could be used in particles observation and holographic data storage system. According to Fourier transform relation between object and its frequency plane and the theory of geometrical optics the system with working wavelength 532nm and resolution 3 m was designed based on ZEMAX. A multi-configuration method was adopted to optimize the system's lenses. In the optical system a diaphragm was placed at the system's spectrum plane and the system demanded a low vacuum to cut down the influences of atmosphere and other particles. The result of finite element analysis indicated that the influences of vacuum pumping to optics spacing and mirror surface shape very minor and the imaging quality not being affected. This system has many advantages such as simple structure good image quality and a high resolution of 3 m. So it has a wide application prospect and can be used both in holographic data storage system and particles observation.