基于消费级无人机倾斜影像的三维测图技术探讨   总被引：2，自引：0，他引：2  

吴献文  张鹏  曾琳 《测绘通报》2019,(7):92-95

倾斜摄影测量技术作为一项新兴的测绘新技术，在各领域中得到了较好的应用，但是用于测绘专业的主流航测飞行器价值昂贵、操控复杂。本文提出了一种利用由消费级无人机获取的倾斜影像制作而成的实景三维模型测绘大比例尺地形图的方法，该方法充分利用了消费无人机价格低廉、操控简便的优点和自动化建模优势，可在短时间内生产出高质量、高精度的实景三维模型和1∶500地形图。实践表明，该方法操作简单，技术路线可行，产品精度符合相关标准规范要求，整体效率优于传统测绘方式，具有推广普及意义。  相似文献   

中国C2C淘宝网络店铺的地理分布   总被引：3，自引：0，他引：3  

王贤文  徐申萌 《地理科学进展》2011,30(12):1564-1569

近年来,随着网络的普及、公众对网络购物认识程度的提高、物流业和经济环境的支持,以淘宝网为代表的C2C电子商务在中国呈现出迅猛发展的态势。本研究基于中国最大的C2C电子商务网站——淘宝网的数据,以中国大陆354个地级城市为研究对象,利用GIS工具和空间计量经济学中的四分位分布、Cartogram分布、Moran’SI指数等方法,对淘宝网的网络店铺进行地理分布的实证研究。研究结果表明,中国的C2C电子商务发展和当地的经济发达程度非常相关。经济发展程度越高、物流业越发达的地区,其C2C淘宝网店数量越多。淘宝店铺的数量分布呈现出自东部沿海向内陆地区明显的梯度降低趋势。东部地区,尤其是以上海和杭州为核心的长江三角洲、以广州和深圳为核心的珠江三角洲地区,C2C网络店铺数量众多,网络购物经济非常发达。西部地区除了若干地区的省会城市之外,大部分地区的C2C电子商务均处于非常落后的状态。对354个城市的空间自相关分析结果表明,中国的C2C电子商务发展存在着非常显著的、正的空间自相关性。即使是考虑人均指标,发展的空间集聚程度仍然非常之高。  相似文献   

Vertical structure and seasonal variation of tidal and residual currents in the northern Huanghai Sea     

SONG Jun  GUO Junru  QIAO Lulu  MU Lin  YAO Zhigang  LIU Yang  LI Huan  BAO Xianwen  SUN Xiaoyan  GAO Jia 《海洋学报(英文版)》2011,30(5):14-22

Analysis of tidal current and sea level has been made based on the observations from the summer of 2006 to the winter of 2007,respectively.The result indicates that a two-layer structure of residual current exists in summer,with its upper layer going northwestward and the lower layer southeastward.In addition,some strong residuals exist in the neighboring depth of the pycnocline during the current period of astronomical tide.In winter,except some individual layersthe residual currents mostly direct to the northwest,from which we can see the fluctuation of abnormal sea-level and the appearance of associated current because of the changes of the wind field.The analysis of tidal ellipse indicates that the direction of the maximum semidiurnal component is clockwise from summer to winter,with an angle of 16-18.Moreover,in summer the semidiurnal component rotates with depth clockwise while the diurnal component counterclockwise.However,the vertical structure is almost homogeneous in winter.  相似文献   

郯庐断裂系研究的新进展——兼论东亚北东向走滑断裂系统   总被引：2，自引：0，他引：2  

刘先文  单巨仁 《地球科学进展》1995,10(2):176-182

对郯庐断裂系研究的最新进展作了介绍。郯庐断裂是多期活动，性质多次转换的巨型断裂，最初的启动时间在晚三叠世末，与南北大陆的碰撞有着直接的关系，早期以走滑（左行）运动为主，伴随挤压和拉伸，范围限于华北地块内部，断裂纵向伸展的高峰期为白垩纪到早始新世，这一时期也是裂陷作用最强的时期，始新世以来以挤压作用为主，东亚走滑断裂系各组成断裂性质复杂，不能以中生代左行平移运动简单概括，走滑断裂系的发展和演化与同时  相似文献   

不同云重叠参数对全球和东亚地区模拟总云量的影响     

王海波  张华  荆现文  谢冰 《气象学报》2018,76(5):767-778

在国家气候中心全球大气环流模式BCC_AGCM2.0中引入一组基于CloudSat/CALIPSO卫星观测的、能够体现真实时空变化特征的云垂直重叠参数（抗相关厚度,L_cf）数据,以减小由云的重叠描述造成的辐射场的不确定性。对比了采用时空变化的云重叠参数和采用恒定云重叠参数的气候模拟结果,发现无论在全球还是东亚区域,采用基于卫星观测的云重叠参数对模拟的总云量都有一定程度的改进。采用时空变化的云重叠参数后,冬、夏两季全球平均总云量与云和地球的辐射能量系统（CERES）卫星资料的误差都减少了1.6%,其中热带对流区域总云量的正偏差和副热带地区总云量的负偏差都明显减少,这些有助于正确模拟不同区域间的能量收支差异。在东亚区域,采用时空变化的云重叠参数后,冬、夏两季的东亚区域平均总云量与CERES卫星资料的误差分别减少了1.8%和1.4%。综上所述,基于CloudSat/CALIPSO卫星资料计算得到的L_cf有助于改进大气环流模式对总云量的模拟,从而提高模式对辐射场的模拟精度。   相似文献   

Case analysis of water exchange between the Bohai and Yellow Seas in response to high winds in winter     

Ju  Xia  Ma  Chao  Yao  Zhigang  Bao  Xianwen 《中国海洋湖沼学报》2020,38(1):30-41

Journal of Oceanology and Limnology - Based on the data from a special project titled China’s Offshore Marine Integrated Investigation and Evaluation as well as Regional Ocean Modeling...  相似文献   

城市产业用地集约利用评价研究——以合肥市为例     

路振华  张军连  李宪文  汪秀莲  白晓飞  张嘉 《地域研究与开发》2013,32(2)

以产业用地综合数据库为基础,通过评价指标体系、评价标准和评价模型构建,实现基于区域的城市产业用地集约利用评价.根据产业发展的影响因素,在传统强度评价的基础上,新增规模、结构和布局评价,并构建三级收敛评价指标体系;以全国综合功能型城市为样本,构建了能适应不同经济发展水平的动态评价标准;引入相对权重模型,通过隶属函数计算构建评价模型.以合肥市为样本,开展集约利用评价,结果显示:(1)禁止发展产业用地面积偏大是总体集约度偏低的最主要因素;(2)距离聚集度也是限制性因子之一;(3)规模合意度与强度合意度评价结果适中.  相似文献   

曲折海湾中潮汐和环流的数值研究   总被引：1，自引：1，他引：0  

YU Huaming  WANG Zhaohu  KUANG Liang  WANG Lu  BAO Xianwen  WU He  WANG Xin  DENG Xiaodong 《海洋学报(英文版)》2015,34(1):119-128

The Shacheng Bay(SCB) is one of the most complex coastal bays in southeast China and due to the fact of complicated geometry and dynamic coastal processes, it is considered as a challenging area for the numerical simulation of its hydrodynamic characteristics. The most advanced finite volume ocean model, finite-volume coastal ocean model(FVCOM), has adopted to simulate this hydrodynamic system, where tidal currents, tidal residual current and dye diffusion processes were studied and analyzed quantitatively. The validation of this numerical model matches well with various observation data, including elevation and current data. The misfit of a tidal elevation has a relative standard error of 3.66% and 4.67% for M2 and S2 tide components. The current validation shows a good match with an average error of 10 cm/s and 8° in the speed major axis and its direction respectively between the simulation and the measurement. This proves the robustness and reliability of this model. It is also found that the cape effect is significant and important in this system. The dye diffusion simulations show a 53 d flushing period for the whole inner bay waterbody. The results are of its first kind for understanding the hydrodynamic system in the SCB and they can provide helpful and trustful scientific information for others.  相似文献   

Evaluating the Impacts of Cloud Microphysical and Overlap Parameters on Simulated Clouds in Global Climate Models     

Haibo WANG  Hua ZHANG  Bing XIE  Xianwen JING  Jingyi HE  Yi LIU 《大气科学进展》2022,39(12):2172-2187

The improvement of the accuracy of simulated cloud-related variables, such as the cloud fraction, in global climate models (GCMs) is still a challenging problem in climate modeling. In this study, the influence of cloud microphysics schemes (one-moment versus two-moment schemes) and cloud overlap methods (observation-based versus a fixed vertical decorrelation length) on the simulated cloud fraction was assessed in the BCC_AGCM2.0_CUACE/Aero. Compared with the fixed decorrelation length method, the observation-based approach produced a significantly improved cloud fraction both globally and for four representative regions. The utilization of a two-moment cloud microphysics scheme, on the other hand, notably improved the simulated cloud fraction compared with the one-moment scheme; specifically, the relative bias in the global mean total cloud fraction decreased by 42.9%–84.8%. Furthermore, the total cloud fraction bias decreased by 6.6% in the boreal winter (DJF) and 1.64% in the boreal summer (JJA). Cloud radiative forcing globally and in the four regions improved by 0.3%?1.2% and 0.2%?2.0%, respectively. Thus, our results showed that the interaction between clouds and climate through microphysical and radiation processes is a key contributor to simulation uncertainty.  相似文献   

云南大红山铜铁矿床构造地球化学特征          下载免费PDF全文

肖斌  范玉华  李俊  杨光树  戚金栋  孙明书  覃龙江  武贤文  赵应班 《地质找矿论丛》2015,30(3):366-373

选取大红山铜铁矿床典型穿脉进行构造-岩石地球化学编录、系统取样,并对样品稀土元素进行化验分析。研究表明,1该矿区内各类岩(矿石)从矿化构造岩→矿石→未矿化构造岩的稀土总量呈现出逐渐降低的趋势,反映出成矿流体与不同构造岩的水岩反应程度上的差异;2从(La/Yb)N看,矿区同类断裂构造岩的轻稀土分异程度较大,但不同断裂构造岩间的分异性却较为均一,从该区围岩、矿石、构造断裂岩的LREE/HREE与(La/Yb)N值特征中可以看出,轻重稀土元素间的分异程度具有一定的相似性,反映出成矿流体对地层岩石存在着一定的继承性和阶段演化性特征;3从地层岩石→未矿化断裂构造岩→矿化断裂构造岩→块状、条带状矿石,LREE/HREE(5.66~13.27)有逐渐增大的趋势,反映出在断裂过程中,稀土元素发生了迁移。矿区内各类岩(矿)石的δ(Eu)1,δ(Ce)呈弱负异常,显示出成矿作用主要是在相对氧化的环境下进行。  相似文献