北京太平桥街道POI数据的步行指数计算方法

步行指数是量化评估区域可步行性、生活便利程度的有效方法之一。在原始步行指数计算方法基础上加以优化,改变了设施权重使之更加适合我国居民的生活习惯;改变了出行点的选取,使计算结果更加准确。并以北京市丰台区太平桥街道为例计算了该区域步行指数,结果显示太平桥街道可步行性一般,教育、医疗设施较缺乏。     

改进相似性测度的高光谱影像FCM聚类分析

高光谱遥感将反映目标辐射属性的光谱信息与反映目标空间几何关系的图像信息有机地结合在一起,能够实现地面目标的精细分类识别。FCM是一种有效的聚类算法,但存在相似性测度模型单一、分类精度的提高受到限制等问题。文中结合高光谱影像的技术特点,综合考虑光谱曲线的形状、地物辐射亮度及其权重,提出可以更好描述光谱向量之间的相似性的距离测度,并将其引入到FCM聚类模型中。聚类分析试验结果表明：通过改进和优化相似性测度的FCM,可以显著提高高光谱影像聚类精度。     

基于步行安全的生活圈可达性分析——以武汉市为例

在城市交通出行中,行人作为弱势群体,步行安全显得尤为重要.本研究通过街景图片识别三类步行设施,并叠加机动车流量与人口分布综合计算步行安全性.以步行安全性为道路网阻抗,计算分析了武汉市步行指数及医疗、绿地资源的可达性.结果表明:武汉市步行设施建设有待提升;步行安全存在明显的地区分异,在"两江三镇"分割的情况下,汉口地区步行设施建设总体较为良好,但尚无法负担本地区的车辆及行人需求.在基于步行安全的可达性方面,居民生活步行圈建设良好,汉口地区处于较好区域.     

社区尺度下南京鼓楼区养老设施综合评价研究

针对南京市鼓楼区提出的打造"15 min养老圈"规划,该文选取养老助餐设施为研究对象,基于百度交通距离,结合社区精细尺度,从养老助餐设施数量、服务规模、空间可达性等多维度构建养老助餐设施综合评价模型,测度鼓楼区各社区养老助餐设施建设成果.结果表明:①鼓楼区现有养老助餐设施已覆盖95.5％的老龄人口,基本实现"15 min养老圈"规划,并揭示了未来养老助餐设施重点布局区域;②高斯两步移动搜索法有效地测度了鼓楼区养老助餐设施的空间可达性,鼓楼区约有91个社区的可达性属于中等及以上水平,占比75.8％;③鼓楼区养老助餐设施综合评价达到中等及以上水平的社区占比93.3％,同时也存在养老供需不匹配的问题.     

POI辅助下的道路选取

针对已有的道路选取方法主要考虑道路的几何和拓扑信息,而未考虑道路邻接的设施点对道路的重要性影响,该文利用POI数据,提出一种顾及道路的几何、拓扑和邻接设施点信息的道路选取方法.该方法借助德尔菲法为不同类型POI打分构建道路上下文特征指标,将其与描述道路结构特征的指标整合求得道路重要性值,进而按照方根模型选取排名在前的道路组成选取后的路网.实验结果表明本文方法选取的路网在保持了原始路网的整体结构、密度分布及连通性的同时,较好地顾及了道路上下文设施对道路重要性的影响.     

多源遥感影像水体指数的交互对比

在对地观测系统中,Landsat和EO-1数据比较适合于监测城市水体变化。但是这两种传感器数据的水体指数之间的关系不清楚,针对这一问题。该文利用两对同日过空的Landsat-7ETM+与EO-1ALI影像来查明二者水体指数之间的定量关系,通过回归统计分析来求出两种传感器水体指数之间的转换方程。结果表明,Landsat-7ETM+与EO-1ALI影像分别基于DN数据、IACM反射率数据计算的MNDWI水体指数间,均存在较好的线性相关关系,决定系数均在0.75以上;基于EO-1ALI的MNDWI指数影像信息更为丰富,因为其动态范围大于Landsat-7ETM+。     

基于有向无环图的滑坡-堰塞湖-洪水灾害链模型服务动态编排方法

现有地质灾害模型多以单灾种为主,部署于各类孤立的业务系统中,较少考虑不同灾害之间的复杂链式关系,难以满足多灾种或复杂灾害链等耦合场景数据-模型资源交互运算的综合分析需求。针对上述问题,本文介绍了一种基于改进有向无环图的滑坡-堰塞湖-洪水灾害链模型服务动态编排方法,设计了显式描述灾害链模型的统一描述模型,提出了灾害链有向无环图构建方法,动态构建面向多任务的灾害信息服务链。最后,以白格滑坡-堰塞湖-洪水灾害链复杂场景为例,验证了本文方法的有效性。     

基于综合景观指数的城乡结合部边界划分

总结单一景观指数模型提取城乡结合部边界存在的问题,提出综合景观指数模型。同时指出,唯有将城市扩展方向信息与指数模型相结合,才能提高城乡结合部的提取精度。以成都市为例,应用遥感和GIS技术,根据建立的模型,计算出各判别单元的综合景观指数,并将综合景观指数在0~22之间的判别单元划分为城乡结合部。     

空间主成分分析的城市生活便利度指数研究 ——以长沙市为例

基于高德地图POI(point of interest)开放性数据,以长沙市为研究区域,利用ArcGIS10.4的核密度、空间主成分等空间分析工机具,分析城市公共服务设施的布局特点,并对市域生活便利度进行评价,再结合数理统计中的回归分析,对城市生活便利度进行驱动力因素的综合分析,以探讨城市公共服务设施规划实施的内在机制,为大数据在城乡规划中的应用提供新方法与思路.主要结论如下:①长沙市的各类服务设施城乡空间布局差异明显.②长沙市整体的生活便利度指数偏低,宜居性较差.③第三产业是影响长沙市生活便利度指数的主要因素.④研究区的生活便利度指数与路网核密度空间上的空间关联性明显,需重视路网结构调整与完善,以增加城市生活便捷程度.     

融合纹理信息的实景三维模型简化算法

针对二次误差测度(QEM)网格简化算法难以保留局部细节特征的缺点,该文提出了一种融合纹理信息的网格简化算法.该算法通过高斯滤波和拉普拉斯运算对纹理贴图预处理来获取像素点的纹理高低值,并以此改变边折叠代价来优化简化效果,从而有效保留三维网格模型的细节特征,助于多层次细节特征等后续操作.该文依据倾斜摄影获取影像构网生成的三维网格数据为试验数据,采用该文算法进行试验,并与传统QEM算法比较.结果表明,该文算法简化效率及简化精度均高于QEM算法.     

阿克苏河-塔里木河水系水质污染遥感监测与评价

 采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的 污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体 污染变化曲线,得出污染物浓度随着远离上游而增加。     

Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data

The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw.     

Landslide risk analysis between Giri and Tons Rivers in Himachal Himalaya (India)

The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies.     

Gravity Changes Before Large Earthquakes in China: 1998-2005

Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200...     

GNSS系统及其技术的发展研究

阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议.     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Virtual Australia: its key elements – know,think, communicate

Abstract

Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised.     

地理数据库的关系模型及其实现

本文从以图论观点分析地理实体入手,系统阐述了地理数据库关系模型的设计法和过程。作者于1984年4～9月间在微型机上设计建立了关系型地理数据库的实方验系统(RGDB)。该系统采用了本文提出的关系模型,采用了可动态扩库的子库组合结构,这种结构具有灵活性和提高空间利用率的优点。RGDB含有多种功能的数据操作命令,除了具有一般检索功能外,还能进行“开窗”选取和十分“自由”的映象选取。本文对RGDB系统的主要性能和实现途径作了扼要介绍。     

Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services

Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.     

基于WebGL的三维智慧管网系统的设计与实现

随着城市面貌日新月异,地下管网的建设也在持续推进,作为城市的地下“神经网络”,全天24 h保障城市的正常运转和发展。本文以实现城市管网管理系统的高可用、无插件、智能化为目标,采用“地上地下一体”“二三维一体”的设计理念,研究基于WebGL的三维智慧管网系统的关键技术,实现了管线设施管理的信息数字化、空间化与图形化。