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Research on spatial-variant property of bistatic ISAR imaging plane of space target 被引量:5
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作者 郭宝锋 王俊岭 +2 位作者 高梅国 尚朝轩 傅雄军 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第4期507-520,共14页
The imaging plane of inverse synthetic aperture radar (ISAR) is the projection plane of the target. When taking an image using the range-Doppler theory, the imaging plane may have a spatial-variant property, which c... The imaging plane of inverse synthetic aperture radar (ISAR) is the projection plane of the target. When taking an image using the range-Doppler theory, the imaging plane may have a spatial-variant property, which causes the change of scatter's projection position and results in migration through resolution cells, In this study, we focus on the spatial-variant property of the imaging plane of a three-axis-stabilized space target. The innovative contributions are as follows. 1) The target motion model in orbit is provided based on a two-body model. 2) The instantaneous imaging plane is determined by the method of vector analysis. 3) Three Euler angles are introduced to describe the spatial-variant property of the imaging plane, and the image quality is analyzed. The simulation results confirm the analysis of the spatial-variant property. The research in this study is significant for the selection of the imaging segment, and provides the evidence for the following data processing and compensation algorithm. 展开更多
关键词 space target bistatic ISAR imaging plane spatial-variant property
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Spatial-Variant Geometric Phase of Hybrid-Polarized Vector Optical Fields
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作者 司宇 孔令军 +5 位作者 张瑜 任志成 潘岳 涂成厚 李勇男 王慧田 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第4期50-54,共5页
We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young's two-slit interferometer instead of the widely used Mach-Zehnder ... We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young's two-slit interferometer instead of the widely used Mach-Zehnder interferometer. This spatial geometric phase can be manipulated by engineering the spatial configuration of hybrid polarizations, and is directly related to the topological charge, the local states of polarization and the rotational symmetry of hybrid-polarized vector optical fields. The unique feature of geometric phase has implications in quantum information science as well as other physical systems such as electron vortex beams. 展开更多
关键词 spatial-variant Geometric Phase of Hybrid-Polarized Vector Optical Fields VOF HP
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贵州威宁1997-2017年冰雹时空变化特征分析 被引量:7
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作者 曾勇 邹书平 +2 位作者 曹水 陈林 黄钰 《高原山地气象研究》 2018年第2期23-27,96,共6页
利用威宁县37个人影作业点收集1997~2017年35个乡镇的地面降雹资料,应用统计学方法和Arc Gis地理信息分析工具,分析了威宁县冰雹日的年际、月际、日变化特征、空间分布特征以及海拔高程与降雹频次相关性。分析结果表明:威宁县年平均冰... 利用威宁县37个人影作业点收集1997~2017年35个乡镇的地面降雹资料,应用统计学方法和Arc Gis地理信息分析工具,分析了威宁县冰雹日的年际、月际、日变化特征、空间分布特征以及海拔高程与降雹频次相关性。分析结果表明:威宁县年平均冰雹日数为15.3d,冰雹日数的年际变化总体呈现先减少后增加趋势,但冰雹日数均小于20世纪末期;冰雹日数M-K检验表明从2003年开始冰雹日数呈逐渐上升趋势,在2010年后出现冰雹日数突变现象;冰雹主要发生在4~8月,占整个降雹日的98.36%,春季、夏季多,秋季、冬季少。春季冰雹日数占31.15%,夏季冰雹日数占67.21%;一天内冰雹主要发生在13~21时,占全部冰雹发生次数的85.07%,即午后到傍晚发生频率高;冰雹主要出现在县的北部、中部、西部至西北部、南部至西南部一线,各个乡镇海拔高程与降雹次数存在正相关,相关系数为0.412,降雹次数随地形高程增加呈现增加趋势,降雹次数与经纬度差异没有相关性。以上这些结论可为威宁县冰雹预报指标研究和开展人工防雹提供科学参考,为冰雹防灾减灾提供技术支撑。 展开更多
关键词 冰雹 冰雹日 年际变化 降雹频次 时空分布
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