Skyline在城市部件管理中的应用

城市部件作为城市网格化管理的重要内容,是我国数字城市技术应用领域的重大突破。针对目前城市部件网格化管理主要是2维展现的技术特点,提出一种基于Skyline的3维技术在城市部件管理中的应用方案。结合城市部件网格化管理的原则,利用Oracle存储数据,以Skyline6．1为3维软件平台,使用．Net系列可视化程序开发工具,采用B／S框架,实现了城市部件在3维可视化技术的基础上进行网格化管理。     

Characterization of agroecosystem based on land utilization indices using remote sensing and GIS

Information on various agricultural resource parameters at various levels is essential for proper management and efficient resource allocation for sustainable agricultural development. Limitations in ground-based method have encouraged the use of satellite data coupled with geographical information system (GIS) in providing spatial as well as temporal information over large and inaccessible areas. In the present study, an attempt has been made to generate raster maps using remote sensing and GIS techniques to characterize the agroecosystem of South 24 Paraganas district of West Bengal, based on land utilization indices. Information on multi-season landcover derived from the analysis of the multi-temporal RADARSAT-1 SAR and IRS-ID LISS III data as well as other ancillary information in GIS environment are the basic inputs used in the study. The present analysis shows that northern and northwestern parts are more diverse in terms of agricultural intensification as compared to the southern and northeastern parts whereas the central parts show moderate density. In terms of carrying capacity, the high carrying capacity has been observed in the southern to northeastern parts whereas the northwestern and central parts show moderate and northern parts show low carrying capacity. Overall, the characterization of agroecosystem using land utilization indices can be identified as major input to formulate a management plan for sustainable agriculture with concerns for the environment.     

土地利用数据库中大比例尺面状道路数据缩编研究

根据建立大比例尺多级土地利用数据库的需要,在进行面状道路数据综合时,对道路进行分类,保留需保持面状的道路面,将不符合要求的道路从网络状道路面中分离出来,并根据需要予以转线或删除,形成新的小比例尺的线面混合道路数据。同时,将删除的道路面分割并归并进相邻图斑,以保证土地数据面状连续的特点。     

GPS-RTK在城市部件普查中的应用

部件普查是建立数字化城市中一项重要的基础工作。城市部件普查一般工作量大、工期短,借助先进的GPS-RTK定位技术,不仅可以提高定位的精度,而且可以大大提高工作效率。文章探讨了GPS-RTK定位技术在城市部件普查中工作步骤和工作方法。     

航空工件结冰进程的视觉量测方法研究

航空工件在低温高湿度条件下表面很容易结冰,结冰的速度和结冰的厚度影响航空工件上传感器的性能,这类传感器在设计制造过程中需要在模拟工作环境下进行试验和测试,以确定对传感器进行保温或加热处理设计。本文研究了利用计算机视觉测量技术对冰风洞内工件结冰进程进行视觉测量的方法,并进行了模拟试验,取得了良好的效果,为以后类似工件检测工作提供技术参考。     

基于近景摄影测量的规则几何部件的建模研究

基于近景摄影测量的方法重建具有规则的几何模型的部件需要参数化的表达方法,利用已知模型确定的几何性质,在影像上提取特征并量测确定模型的空间位置和自由度,在精度要求较高的情况下,需要结合影像进行高精度的匹配量测。通过对线框模型的三角化获取适合纹理映射的表面模型,从而尽可能的构建出真实感的部件。     

利用剖面测线磁场数据反演三度磁性体参数

常规的格网状加密探测方式很难适用于航空手段对水下动态磁性体进行快速定位与识别,为此,尝试采用磁性体周围少量的几条测线对其进行探测,并利用改进的最小二乘法反演三度磁性体空间位置及磁性参数。根据观测值与磁矩的线性关系以及磁性体中心位置的非线性关系,对磁性体位置与磁性参数分步求解。理论模型推导过程中,顾及了地磁背景场影响和多磁性体情况,给出了相应的数据处理方法。通过实测数据验证表明,提出的方法是收敛的,能达到很高的磁性体几何及磁性参数解算精度。     

由直线和曲线混合组成的地形符号在DCS中的处理

在ＤＣＳ输出的地籍图上，有许多由直线段和曲线段组成的地物符号，用传统方法处理难以取得理想的绘图效果。本文在分析ＤＣＳ数据结构和属性码的基础上，提出了曲线部分按三次参数样条曲线逼近，讨论了直线段和曲线段的各种组合情况，并且通过正确地选择边值条件使二者之间．的连接比较符合实际。最后扼要分析了该类线段按虚线绘出时的处理方法。     

附约束条件的零件轮廓线的多特征提取

在常用的多特征提取方法的基础上提出一种附加约束条件的零件轮廓线的多特征提取方法,即在已有方法提取的多特征结果上附加轮廓上圆弧与直线相切、相邻圆弧与圆弧相切等约束条件,对轮廓上的特征进行迭代精确提取,将组成轮廓的各特征如直线、圆弧和圆,进行精确分段识别,获得各特征的参数。最后使用模拟图像和实际的工业零件图像分别进行了试验验证,结果证明约束关系的引入能够有效地提高轮廓线多特征提取的精确度。     

MASNUM海浪数值模式并行化实现

通过对MASNUM海浪数值模式的串行程序的结构研究和对串行模式进行并行化分析,提取了可并行部分的程序计算模块。利用消息传递接口(MPI)和Fortran语言,将模式中可并行计算部分进行了划分,同时分配多个进程并行计算。测试结果表明,MASNUM并行模式的效率较高,满足业务化预报的要求。     

Consistency among parts and aggregates: A computational model

Heterogeneous geographic databases contain multiple views of the same geographic objects at different levels of spatial resolution. When users perceive geographic objects as one spatial unit, although they are physically separated into multiple parts, appropriate methods are needed to assess the consistency among the aggregate and the parts. The critical aspect is that the overall spatial relationships with respect to other geographic objects must be preserved throughout the aggregation process. We developed a systematic model for the constraints that must hold with respect to other spatial objects when two parts of an object are aggregated. We found three sets of configurations that require increasingly more information in order to make a precise statement about their consistency: (1) configurations that are satisfied by the topological relations between the two parts and the object of interest; (2) configurations that need further information about the topological relation between the object of concern and the connector in order to be resolved unambiguously; and (3) configurations that require additional information about the topological relation between the aggregate's boundary and the boundary or interior of the object of interest to be uniquely described. The formalism extends immediately to relations between two regions with disconnected parts as well as to relations between a region and an arbitrary number of separations.     

棕版地形图上等高线的自动提取和批量赋值

地形等高线在地学研究中有重要意义,地形图上等高线的自动提取和赋值是地理信息系统中的一个重要课题。本文引入图像分割技术,将全要素棕版地形图尺度分割生成图斑后,再通过在红、绿、蓝各波段上设置平均属性范围,对地形等高线进行了自动提取。借助图像处理技术对不同类型的等高线断点进行了连接。通过编写程序对获取的地形等高线进行交互批量赋值,最终较好地解决了等高线提取中的间断、交叉和粘连等问题。     

重庆市城市部件普查确权方法研究及应用

作为数字城管的工作基础,城市部件的权属准确性已成为提升案件派遣效能的关键性因素,笔者结合重庆市部件普查工作情况和经验总结,提出了“总协调”、“分类别”、“划区域”的部件确权工作思路。这种新的工作思路应用到实际工作中,可以进一步提高确权工作的效率和质量。本文对这种确权工作方法进行了详细的介绍,并结合实际应用情况进行了简要的探讨。     

浅析城市部件的数字化采集方法

为了提高城市管理水平、实现科学和规范化管理,借鉴"数字城市管理系统"模式的成功案例,根据网格化城市管理系统的要求,实施网格化管理信息化建设工程,进行城市部件的数据采集工作,并将所获取的数据成功地转入数据库。本文根据城市部件数字化采集工作的实际经验和做法,从城市部件的类型及编码、城市部件数据采集方法和精度要求以及城市部件成果数据库的建立三个部分进行了分析和阐述,以供测绘工作者参考。     

图形存储结构对地图制图软件中图形编辑功能的影响

地图制图软件中,图形编辑功能与其撤消/重做(Undo/Redo)功能是必不可少的,一个好的图形存储结构能方便图形编辑操作及其Undo/Redo功能的实现。文中介绍了基于Oracle数据库的地图制图软件中图形数据的储存结构,其中包括数据库中的图形储存;图形数据从数据库中读入内存后的存储结构和图形编辑数据存储结构。在储存结构的基础上提出图形编辑及其Undo/Redo执行方法,并给出具体的实现代码,实验证明该方法提高了运行效率,减少了内存消耗。     

全国铀矿资源空间数据库建模

全国铀矿资源空间数据库的建设是开展全国铀矿资源成矿规律总结及潜力评价的研究工作的重要前提,为今后开展矿产勘查的规划部署研究奠定了扎实的信息基础,有利于积极开展矿产远景调查和综合研究,科学评估区域矿产资源潜力。本文主要介绍了全国铀矿资源空间数据库建模的方法、步骤,并将空间数据库中的图层划分为地理类逻辑层、基础地质类逻辑层、铀矿地质类逻辑层、物化遥逻辑层、整饰逻辑层共五个主类,最后详细阐述了空间数据库中的信息编码问题——图件编码、图层编码及属性表编码。     

Subdivision of polygon parcel in land-use data generalization

In land-use data generalization, the removal of insignificant parcel with small size is the most frequently used operator. Traditionally for the generalization method, the small parcel is assigned completely to one of its neighbors. This study tries to improve the generalization by separating the insignificant parcel into parts around the weighted skeleton and assigning these parts to different neighbors. The distribution of the weighted skeleton depends on the compatibility between the removed object and its neighbor, which considers not only topological relationship but also distance relationship and semantic similarity. This process is based on the Delaunay triangulation model. This paper gives the detailed geometric algorithms for this operation.     

基于多尺度分析的遥感影像融合研究

本文对SPOT5的多光谱波段和全色波段在像素级的融合层次上运用多尺度分析的方法进行了融合试验,主要用了小波变换和Curvelet变换的方法,这两种变换方法都能把图像分解为低频的近似图像和高频的细节图像,采用一定的融合规则对分解后的图像进行融合,并进行反变换得到融合后的图像,并把基于多尺度分析的融合结果与传统的融合方法进行了对比分析。结果表明,基于多尺度分析的融合方法比传统的PCA、Brovey融合方法效果要好;而Curvelet变换融合在光谱保持度及空间信息提高方面都比小波变换融合有所提高。     

Coregistration Based on Three Parts of Two Complex Images and Contoured Windows for Synthetic Aperture Radar Interferometry

The coregistration of complex image pairs is a very important step in synthetic aperture radar interferometry (InSAR) data processing. This letter proposes a novel coregistration method that only needs three arbitrary parts of the two complex images instead of four parts in the existing coregistration methods. This method constitutes an integrated three-part method for InSAR data processing with our contoured-correlation-interferometry method for phase-image generation. Saving one part transmission makes a significant advantage when processing SAR images on satellites. Furthermore, we demonstrate that, by means of using fringe contoured windows instead of squared windows, the accuracy of the coregistration for both the three-part coregistration method and the existing methods can be improved considerably     

Subdivision of polygon parcel in land-use data generalization

In land-use data general-ization, the removal of insignificant parcel with small size is the most fre-quently used operator. Traditionally for the generalization method, the small parcel is assigned completely to one of its neighbors. This study tries to improve the generalization by sepa-rating the insignificant parcel into parts around the weighted skeleton and assigning these parts to different neighbors. The distribution of the weighted skeleton depends on the com-patibility between the removed object and its neighbor, which considers not only topological relationship but also distance relationship and semantic sim-ilarity. This process is based on the Delaunay triangulation model. This paper gives the detailed geometric al-gorithms for this operation.