An address regional tessellation method for spatial subdivision and geocoding in digital earth system     

《International Journal of Digital Earth》2013,6(10):825-839

With the increased use of locational information, spatial location referencing and coding methods have become much more important to the mining of both geographical and nongeographical data in digital earth system. Unfortunately, current methods of geocoding, based on reverse lookup of coordinates for a given address, have proven too lossy with respect to administrative and socioeconomic data. This paper proposes a spatial subdivision and geocoding model based on spatial address regional tessellation (SART). Given a hierarchical address object definition, and based on the ‘region of influence’ characteristics of an address, SART creates multiresolution spatial subdivisions by irregular and continuous address regions. This model reflects most of the geographical features and many of the social and economic implications for a given address. It also better reflects the way people understand addresses and spatial locations. We also propose an appropriate method of geocoding for standard addresses (SART-GC). The codes generated by this method can record address footprints, hierarchical relationships, and spatial scales in a single data structure. Finally, by applying our methods to the Shibei District of Qingdao, we demonstrate the suitability of SART-GC for multi-scale spatial information representation in digital earth systems.  相似文献   

A piecewise based high-precision registration of InSAR data     

Yang Jie  Liao Mingsheng  Yang Wen  Zhang Li 《地球空间信息科学学报》2013,16(1):100-103

In Synthetic Aperture Radar (SAR) interferometry, the precise co-registration is a key problem to obtain the fine interferogram. Theoretically, 1/10 pixel accuracy is essential. Once the control points are determined, the relative rectification (pixel re-sampling) is also the important procedure. In this paper, a piecewise transformation algorithm based on Delaunay Tessellation algorithm is developed. The strategy is to “anchor” geographically all control points and transform the imagery on the basis of triangle by triangle. The piecewise algorithm, the accuracy evaluation and the preliminary results are described. The experiment result shows that the piecewise transformation out-performes the traditional polynomial transformation.  相似文献   

ESP: a tool to estimate scale parameter for multiresolution image segmentation of remotely sensed data     

Lucian Drǎguţ  Dirk Tiede  Shaun R. Levick 《International journal of geographical information science》2013,27(6):859-871

The spatial resolution of imaging sensors has increased dramatically in recent years, and so too have the challenges associated with extracting meaningful information from their data products. Object-based image analysis (OBIA) is gaining rapid popularity in remote sensing science as a means of bridging very high spatial resolution (VHSR) imagery and GIS. Multiscalar image segmentation is a fundamental step in OBIA, yet there is currently no tool available to objectively guide the selection of appropriate scales for segmentation. We present a technique for estimating the scale parameter in image segmentation of remotely sensed data with Definiens Developer®. The degree of heterogeneity within an image-object is controlled by a subjective measure called the ‘scale parameter’, as implemented in the mentioned software. We propose a tool, called estimation of scale parameter (ESP), that builds on the idea of local variance (LV) of object heterogeneity within a scene. The ESP tool iteratively generates image-objects at multiple scale levels in a bottom-up approach and calculates the LV for each scale. Variation in heterogeneity is explored by evaluating LV plotted against the corresponding scale. The thresholds in rates of change of LV (ROC-LV) indicate the scale levels at which the image can be segmented in the most appropriate manner, relative to the data properties at the scene level. Our tests on different types of imagery indicated fast processing times and accurate results. The simple yet robust ESP tool enables fast and objective parametrization when performing image segmentation and holds great potential for OBIA applications.  相似文献   

对称荷载正多边形孔洞弹性应力解析逼近方法     

朱大勇  蔡永祥 《岩土力学》2016,37(Z2):60-66

提出一种简单有效的计算方法,求解对称荷载作用下含正多边形孔洞无限平面体的弹性应力解。将孔洞内边界向两侧延伸至应力可忽略的远处,其外侧构成半无限平面体。相邻两个半无限平面体有一个公共域,其中一个半无限平面体顶边延伸至相邻两个半限平面体体内。孔洞内边界上面力是已知的,延伸至两相邻半无限平面体体内的顶边上面力可先假设,由弹性理论求出半无限平面体体内应力,再计算相邻半无限平面体顶边上面力,根据对称性得到本半无限平面体顶边上面力改进值,迭代求解直至收敛。该方法具有计算过程简单、精度高等优点。算例分析表明,该方法求解的工程尺度下孔洞周边应力场与复变函数方法、有限元方法计算结果吻合,拟合计算的孔边角点处应力奇异性次数与理论解基本一致。  相似文献   

明基床上开孔沉箱总力矩试验研究     

张玉彬  孙大鹏  夏志盛 《海洋工程》2012,30(3):51-58

通过二维水槽内规则波以及不规则波作用下开孔沉箱的受力试验研究,分析研究了明基床上开孔沉箱所受的总力矩与相对基床高度、消浪室相对宽度、相对水深、波陡以及开孔率等影响因素间的相关关系,并利用最小二乘法给出总力矩比值(开孔沉箱/实体沉箱)与其影响因素间的拟合公式,同时将计算值与试验值对比,二者吻合较好,所得经验关系式可供工程设计参考。  相似文献   

基于1∶10000地形数据更新1∶50000 DEM的研究试验     

段修梅  王东华  赵仁亮 《地理信息世界》2012,(1):39-42

对1:50 000 DEM数据库的现状进行了分析,提出了利用1:10 000地形数据更新1:50 000 DEM的主要内容和两种方法,简要介绍了地形变化检测方法。通过对试验区规则格网DEM成果的精度检查验证了方法的可行性。客观分析了本次试验的特点和不足,为以后大比例尺地形数据更新小比例尺DEM等相关工作提供了技术参考。  相似文献   

����ƽ��ϵͳģ�����İ������������     

高宁  崔希民  高彩云  王果  赵万东 《大地测量与地球动力学》2012,32(1):114-117

????????????У????????????д???????????????????????????????????????????????????????????????????e??????????С????????????????????????????????R??????????????????????????????????????????????????????????????????С??????????????б?????????????????????????Ч??????????????д?????????????н?????????????  相似文献   

测量中不适定问题的统一解的推导     

黄河 《测绘与空间地理信息》2012,35(11):196-198,201

病态问题和秩亏问题是测量中常见的不适定问题,从正则化矩阵和正则化参数入手对存在于测量中的控制网平差、大地测量反演、GPS快速定位、拟合推估系统误差处理等不适定问题进行处理,成为当前的研究热点。同时,经过统一解的建立,对秩亏问题病态性问题实行新的解法,改进了生产实践中的测量精度,具有一定的学术价值和商业价值。  相似文献   

A new formulation of garnet–clinopyroxene geothermometer based on accumulation and statistical analysis of a large experimental data set     

D. NAKAMURA 《Journal of Metamorphic Geology》2009,27(7):495-508

Published experimental data including garnet and clinopyroxene as run products were used to develop a new formulation of the garnet–clinopyroxene geothermometer based on 333 garnet–clinopyroxene pairs. Only experiments with graphite capsules were selected because of difficulty in estimating the Fe³⁺ content of clinopyroxene. For the calibration, a published subregular‐solution model was adopted to express the non‐ideality of garnet. The magnitude of the Fe–Mg excess interaction parameter for clinopyroxene (W_FeMg^Cpx), and differences in enthalpy and entropy of the Fe–Mg exchange reaction were regressed from the accumulated experimental data set. As a result, a markedly negative value was obtained for the Fe–Mg excess interaction parameter of clinopyroxene (W_FeMg^Cpx = ? 3843 J mol^?1). The pressure correction is simply treated as linear, and the difference in volume of the Fe–Mg exchange reaction was calculated from a published thermodynamic data set and fixed to be ?120.72 (J kbar^?1 mol^?1). The regressed and obtained thermometer formulation is as follows: where T = temperature, P = pressure (kbar), A = 0.5 X_grs (X_prp ? X_alm ? X_sps), B = 0.5 X_grs (X_prp ? X_alm + X_sps), C = 0.5 (X_grs + X_sps) (X_prp ? X_alm), X_prp = Mg/(Fe²⁺ + Mn + Mg + Ca)^Grt, X_alm = Fe/(Fe²⁺ + Mn + Mg + Ca)^Grt, X_sps = Mn/(Fe²⁺ + Mn + Mg + Ca)^Grt, X_grs = Ca/(Fe²⁺ + Mn + Mg + Ca)^Grt, X_Mg^Cpx = Mg/(Al + Fe^total + Mg)^Cpx, X_Fe^Cpx = Fe²⁺/(Al + Fe^total + Mg)^Cpx, K_D = (Fe²⁺/Mg)^Grt/(Fe²⁺/Mg)^Cpx, Grt = garnet, Cpx = clinopyroxene. A test of this new formulation to the accumulated data gave results that are concordant with the experimental temperatures over the whole range of the experimental temperatures (800–1820 °C), with a standard deviation (1 sigma) of 74 °C. Previous formulations of the thermometer are inconsistent with the accumulated data set; they underestimate temperatures by about 100 °C at >1300 °C and overestimate by 100–200 °C at <1300 °C. In addition, they tend to overestimate temperatures for high‐Ca garnet (X_grs ≈ 0.30–0.50). This new formulation has been tested against previous formulations of the thermometer by application to natural eclogites. This gave temperatures some 20–100 °C lower than previous formulations.  相似文献   

卷破波作用下沙质岸滩剖面形态判别式初探     

蒋昌波  伍志元  陈杰  邓斌  隆院男  李廉洁 《海洋学报(英文版)》2017,36(9):91-100

通过波浪水槽实验,开展不同类型波浪作用下的沙质岸滩演化规律研究工作。本次实验研究不考虑比尺,采用1:10与1:20组成的复合沙质斜坡对岸滩进行概化,选取规则波和椭圆余弦波两种典型波浪作用,对波浪的传播、变形和破碎、上爬、回落过程以及波浪作用前后沙质岸滩床面地形进行了观测,探讨波浪作用下沙质岸滩剖面演化规律。本文实验工况中,规则波作用下,岸滩剖面呈现出沙坝剖面和滩肩剖面,椭圆余弦波作用下的岸滩剖面均呈滩肩形态,发现岸滩剖面形态不仅与波浪作用类型、强度、周期等因素相关,还与波浪破碎的强度等因素有关。通过对实验过程中现象的进行观察和分析,引入了卷破波水舌冲击角的概念。对波浪卷破破碎后形成的水流挟沙运动与岸滩剖面形态的关系进行定性分析,对水舌冲击角与Irribarren参数之间的关系进行定量分析,基于Irribarren参数与岸滩剖面形态的关系初步建立了波浪作用下沙质岸滩剖面形态判别关系式。通过本文实验结果和前人实验结果对趋势线进行拟合,求得其判别系数,判别式能够较好地划分淤积型岸滩、侵蚀型岸滩及过渡型岸滩三种岸滩形态。  相似文献