以符号为中心的统计地图制图模板技术研究     

张晓楠  华一新  李鹤元  朱玲  张政 《测绘科学技术学报》2015,(3):300-304

地图制图自动化与智能化是当前制图领域研究的热点问题,模板制图是实现制图自动化,提高制图效率的一种手段。在探讨模板制图原理的基础上,分析了现有制图模板的特点及其应用模式上存在的不足,设计了以符号为中心的统计地图制图模板的应用模式,提出了以符号为中心的统计地图制图模板技术,凸显了统计地图制作过程中符号的重要地位。以此为基础,深入剖析了统计制图模板、统计专题图层、图面表达结果三者之间的区别与联系,研究了以符号为中心的统计地图制图模板构建技术、存储技术以及匹配技术,并进行了系统应用,验证了这一技术的可行性和有效性。  相似文献   

基于灭点的真正射影像阴影自动剔除方法     

王晓南  黎书芬 《测绘通报》2011,(4)

真正射影像是利用数字表面模型反投原始影像重采样得到的,在得知太阳方位后便能够自动剔除原始影像上的阴影。基于灭点理论,提出一种计算太阳方位的方法,以达到剔除真正射影像阴影的目的。  相似文献   

Evaluation of the diagnostic ratios for the identification of spilled oils after biodegradation   总被引：3，自引：1，他引：2  

Chuanyuan Wang  Xuelu Gao  Zhigao Sun  Zhijiang Qin  Xiaonan Yin  Shijie He 《Environmental Earth Sciences》2013,68(4):917-926

Biodegradation, one of the most important weathering processes, alters the composition of spilled oil, making it difficult to identify the source of the release and to monitor its fate in the environment. A laboratory experiment was conducted to simulate oil spill weathering process of microbial degradation to investigate compositional changes in a range of source- and weathering-dependent molecular parameters in oil residues, and the conventional diagnostic ratios for oil spill identification were also evaluated. The conventional diagnostic ratios of n-alkane displayed obvious changes after biodegradation, especially for Pr/n-C₁₇ and Ph/n-C₁₈ with relative standard deviation more than 118.84 %, which suggests they are invalid for oil source identification of the middle-serious spill. Many polycyclic aromatic hydrocarbons (PAHs) are more resistant to biodegradation process than their saturated hydrocarbon counterparts, thus making PAHs to be one of the most valuable fingerprinting classes of hydrocarbons for oil identification. Biomarker ratios of hopanes and steranes were also useful for source identification even after moderate biodegradation, and the diagnostic ratios from them could be used in tracking origin and sources of hydrocarbon pollution. Finally, the carbon isotopic type curve may provide another diagnostic means for correlation and differentiation of spilled oils, and be particularly valuable for lighter refined products or severely biodegraded oils, the source of which may be difficult to identify by routine biomarker techniques.  相似文献   

应急公安专题符号库制作技术研究     

张晓楠  刘汉生  王慧芳 《测绘工程》2017,26(6)

从公安应急指挥保障和业务需求出发,针对目前应急公安专题符号存在的样式欠完善、规范欠统一、制作程序繁杂等问题,提出应急公安专题符号的概念及分类分级体系,基于Illustrator制作了应急公安专题符号,并基于ArcGIS构建了应急公安专题符号库,取得了较好的用户评价效果,并为提高应急公安专题地图的制作效率和显示效果发挥作用。  相似文献   

地缘环境分析模型图形化建模   总被引：2，自引：0，他引：2  

冯长强  江南  张晓楠  丁昊  武丽丽 《测绘科学技术学报》2017,34(1)

针对日益增加的地缘环境分析模型(GEAM)组织管理需求,在对当前GEAM进行元模型剖分及分类的基础上,重点对GEAM图形化建模进行研究。将图形化建模任务划分为模型组织管理、模型编辑及模型验证与运行3个模块,界定各模块的主要功能,构建GEAM图形化建模框架。利用面向对象思想对图元语义映射与关联、模型验证与运行、模型输出与加载等关键技术进行深入研究与剖析。开发GEAM图形化建模原型系统,并通过对地缘环境单元划分模型进行图形化组建,验证可行性。  相似文献   

一种提取城市多种不透水层的垂直不透水层指数   总被引：1，自引：0，他引：1  

田玉刚  徐韵  杨晓楠 《测绘学报》2017,46(4):468-477

针对中低分辨率影像中不透水层的异质性及其与裸土光谱的易混性两类问题,选用蓝、近红外波段进行线性组合,构建了一种新的不透水层提取指数——垂直不透水层指数(PII)。该指数考虑了不透水层和其他地物在光谱空间的差异与不透水层的内部异质性,并以"不透水层线"与"土壤线"夹角的角平分线作为PII的参照线,实现了自适应的不透水层提取。本文将PII指数应用于武汉和北京不同场景中,并对比归一化建筑物指数(NDBI)、比值居民地指数(RRI)以及生物物理组份指数(BCI)的提取结果。试验表明:1在裸土较少、地形平坦的武汉市区域和裸土较多、地形起伏的北京市区域,PII指数均能有效减弱裸土的混淆影响,不透水层提取精度分别达到96.05%和96.76%,优于其他3种指数;2PII指数不仅增强了不透水层与其他地物的可区分性,还保持了不透水层类内的相似性,在城市不同场景中的不透水层提取精度均能达到90%以上。由于PII指数是一种线性组合形式的指数,能够根据研究区的地物光谱自适应调整指数的方程系数,从而能适用于不同研究区,在裸地较多的地区优势尤为明显。  相似文献   

巴拿马科隆自贸区的发展历程及启示   总被引：4，自引：1，他引：3  

孟广文  刘函  赵园园  王春智  王红梅  鲁笑男 《地理科学》2017,37(6):876-884

采用文献归纳、案例分析等方法,依据贸易与经济地理等理论对科隆自由贸易区的发展历程、特征以及影响因素进行系统归纳与梳理;在此基础上,对科隆自贸区发展的成功经验与存在的问题与挑战进行了系统的总结与分析;最后对中国自由贸易试验区的启示作了初步的分析与探讨。  相似文献   

Zircon U–Pb dating of Pubei granite and strontium isotope from sphalerite of the Xinhua Pb–Zn–(Ag) deposit,Yunkai Area of Guangxi Province,South China     

Minfang Wang  Xubo Zhang  Daohui Pi  Xiaonan Guo 《中国地球化学学报》2016,35(2):156-171

The Yunkai Area is located at the southern South China Block and is part of the Qinzhou Bay-Hangzhou Bay Metallogenic Belt, which is a famous polymetallic mineralization belt. The Xinhua Pb–Zn–(Ag) deposit is located in the western part of Yunkai Area, with an abundance of Pubei batholiths. Zircon U–Pb geochronology of Pubei batholiths shows that crystallization age ranges from 251.9 ± 2.2 to 244.3 ± 1.8 Ma, thus belonging to Indosinian orogeny. Geochemistry and Sr isotopic compositions of the Pubei batholiths show that it is derived from the partial melting of large scale crustal melting during the stage of exhumation and uplifting of the lower-middle crust. In addition, strontium isotope of sphalerite from the Xinhua Pb–Zn–(Ag) deposit, has limited ranges in ⁸⁷Rb/⁸⁶Sr and ⁸⁷Sr/⁸⁶Sr, ranging from 0.4077 to 1.0449, and 0.718720 to 0.725245, respectively. The initial ⁸⁷Sr/⁸⁶Sr ratios of sphalerite ranges between 0.718720 and 0.725245, which is higher than that of upper continental crust and lower than that of the Pubei batholiths, illustrating the fluid might be derived from the mixing of Pubei pluton and upper continental crust.  相似文献   

三维点云初始配准方法的比较分析     

王佳婧  王晓南  郑顺义  朱锋博 《测绘科学》2018,(2):16-23

针对多种多样的三维点云自动初始配准算法,该文依照配准过程中侧重点的不同将其分为基于局部特征描述、基于全局搜索策略和基于统计学概率3个算法类别,对其中具有代表性的FPFH、4PCS、NDT 3种算法进行了配准效率和数据适应性的比较分析。采用4组数据分别使用这3种算法进行配准实验,提出了算法中相关参数的设置方法,验证了它们用于最近点迭代精配准的适用性,并记录相应的配准耗时。实验结果表明,不同算法适用的数据不同,初始配准时可以依据数据的特点选取合适的方法。  相似文献   

Spatial–temporal variations of methane emissions from the Ertan hydroelectric reservoir in southwest China     

Hua Zheng  Xiaojie Zhao  Tongqian Zhao  Falin Chen  Weihua Xu  Xiaonan Duan  Xiaoke Wang  Zhiyun Ouyang 《水文研究》2011,25(9):1391-1396

Methane emissions from hydroelectric reservoirs can comprise a considerable portion of anthropogenic methane. However, lack of data on CH₄ emissions in different geographical regions and high spatial‐temporal variability in the emission rates of reservoirs has led to uncertainties regarding regional emission estimates of CH₄. In the subtropical plateau climate region, we used the Ertan hydroelectric reservoir as a study area. The CH₄ flux at the air‐water interface was assessed by floating chambers and factors influencing emissions, including the distance from the dam, water depth, seasonal variation in wet and dry season, air‐water temperature gradient and wind speed, and was also studied through a year‐long systematic sampling and monitoring experiment. The results showed that the surface of the reservoir was a source of CH₄ during the sampling period and the annual average CH₄ flux was 2·80 ± 1·52 mg m^?2 d^?1. CH₄ flux (and its variation) was higher in the shallow water areas than in the deep‐water areas. CH₄ flux near the dam was significantly higher than that of other locations farther from the dam in the dry season. The seasonal variations of CH₄ emission in wet and dry seasons were minor and significant diurnal variations were observed in wet and dry seasons. Exponential relationships between the CH₄ flux and air‐water temperature gradient were found. Air‐water temperature gradient was an important factor influencing diurnal variations of CH₄ flux in the Ertan hydroelectric reservoir. These results indicate that systematic sampling is needed to better estimate CH₄ flux through coverage of the spatial variation of different water depths, measuring‐point distance from the dam, seasonal variation in wet and dry seasons and changes in climate factors (such as air‐water temperature gradient). Our results also provide a fundamental parameter for CH₄ emission estimation of global reservoirs. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献