南海区域卫星多光谱影像太阳耀斑消除方法

太阳光线被水面直接反射到传感器会造成耀斑污染的现象。高分辨率卫星影像可利用近红外波段消除太阳耀斑。在分析耀斑产生的辐射传输过程的基础上,利用World View-2卫星4波段和8波段多光谱影像设计实验,比较了3种常见的高分辨率太阳耀斑消除算法。结果表明,各种耀斑消除算法的目视效果都较为优秀,定量应用场合下Hedly算法和Goodman算法更有优势。     

面向叙事结构的地理空间情报可视分析方法

以地理空间情报服务于反恐为需求牵引,采用全球恐怖主义数据库(GTD)为数据源,将时空叙事结构作为分析模型,以时间要素和空间要素作为线索,进行地理空间叙事,对事件和对象的多维属性进行可视化,借助多视图人机交互式分析方法和交互技术,构建了基于JavaScript的地理空间情报可视分析平台,并根据分析任务进行了案例分析,为基于活动的地理空间情报研究探索一条新的思路。     

Factors affecting habitat occupancy of fish assemblage in the Gulf of Trieste (Northern Adriatic Sea)

Species composition, richness and abundance of the fish assemblage were studied over six different inshore macrohabitats in the southern part of the Gulf of Trieste (Northern Adriatic Sea) using the visual counts technique. Fifteen environmental variables were taken into consideration in order to determine microhabitat preferences of fish species, using canonical correspondence analysis and electivity indices. The results suggest that the structure of the fish assemblage in shallow habitats is affected by a large number of interplaying factors. Depth, type of bottom and vegetation cover – incorporating both abiotic and biotic variables – are some of the factors responsible for coastal fish distribution. Microhabitat preferences for 29 fish species are presented in the depth range from 0.5 to 3 m.     

校园三维景观建模及其飞行漫游的实现

三维景观建模技术是地理信息系统的重要发展领域。文中以AutoCAD格式的施工设计图为基础,利用三维可视地理信息系统软件IMAGIS 2.3,通过数据的预处理、三维建模、纹理映射,建立了福建师范大学新校区理工楼群模型,并就有关技术问题进行了讨论。     

Follow‐up spectroscopic observations of HD 107148 B: A new white dwarf companion of an exoplanet host star

We report on our follow‐up spectroscopy of HD 1071478 B, a recently detected faint co‐moving companion of the exoplanet host star HD 107148 A. The companion is separated from its primary star by about 35″ (or 1790 AU of projected separation) and its optical and near infrared photometry is consistent with a white dwarf, located at the distance of HD 107148 A. In order to confirm the white dwarf nature of the co‐moving companion, we obtained follow‐up spectroscopic observations of HD 107148 B with CAFOS at the CAHA 2.2 m telescope. According to our CAFOS spectroscopy HD 107148 B is a DA white dwarf with an effective temperature in the range between 5900 and 6400K. The properties of HD 107148 B can further be constrained with the derived effective temperature and the known visual and infrared photometry of the companion, using evolutionary models of DA white dwarfs. We obtain for HD 107148 B a mass of 0.56 ± 0.05 M_⊙, a luminosity of (2.0 ± 0.2) × 10^–4 L_⊙, log g [cm s^–2]) = 7.95 ± 0.09, and a cooling age of 2100 ± 270 Myr. With its white dwarf companion the exoplanet host star HD 107148 A forms an evolved stellar system, which hosts at least one exoplanet. So far, only few of these evolved systems are known, which represent only about 5 % of all known exoplanet host multiple stellar systems. HD 107148 B is the second confirmed white dwarf companion of an exoplanet host star with a projected separation to its primary star of more than 1000 AU. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

盆地模拟数据可视化系统研究

盆地模拟技术在油气资源研究中具有非常重要的意义。但是,没有数据可视化技术的支持,庞大而丰富的成果资料往往使地质学家在地质分析、地质解释中难以达到理想的效果。为此,本文利用计算机图形学的基本理论和计算机可视化技术,并综合应用盆地模拟数据结构特点,设计开发了盆地模拟数据可视化软件系统。该系统在用于塔里木盆地的三维盆地模拟中,发挥了非常重要的作用,并为塔里木盆地的油气资源进一步研究提供了依据。     

GeoSQL: 一种可视化空间扩展SQL查询语言

根据结构化查询语言ＳＱＬ的基本原理,设计了空间查询语言ＧｅｏＳＱＬ及其表达形式、界面设计和实现方法。ＧｅｏＳＱＬ的特色为：①采用子查询（ｓｕｂｑｕｅｒｙ） 重组ＦＲＯＭ 语句,使其符合一般空间操作的程序;②ＧｅｏＳＱＬ的界面设计融入了Ｉｃｏｎ、Ｌｉｓｔｂｏｘ 等可视化部件,易于查询文本的形成,且减少了语法错误。     

基于Anubis的北斗观测数据质量分析

为分析BDS在亚太地区及其他范围内的数据质量差异,选取2个国内和3个境外MGEX连续跟踪站10 d的数据,利用Anubis软件对BDS及GPS数据质量进行对比和可视化分析,同时着重分析C37以上不同类型轨道卫星的多路径效应及信噪比.结果表明,BDS各测站的数据完整率均为100％;各频段各类型卫星的伪距多路径平均值均低于...     

Time‐lapse video observation of erosion processes on the Black Marls badlands in the Southern Alps,France

In order to clarify the erosion processes on a marly bare slope in the Southern Alps, the erosion processes in a steep and erodible slope composed of the Black Marls Formation were observed by a time‐lapse video camera. The observations revealed that miniature debris flows (MDFs) occurred at the time of the rainfall‐runoff event in which the most severe erosion took place in the whole observation period of 3 months. Analysis of the camera images showed some characteristics of the MDFs, and these are discussed in the context of real rainfall‐runoff phenomena observed at the outlet of a small experimental basin including the visually observed slope. The following results were obtained. (1) A rough estimation of the total amount of sediment discharge by the MDFs showed that it was not negligible quantitatively. (2) The MDFs occurred only during the rising limb of the hydrograph during 6 minutes. (3) Based on this observation and a review of the literature, in a very steep and highly erodible slope, MDFs or similar phenomena might play an important role in the erosion and transport processes. Copyright © 2008 John Wiley and Sons, Ltd.