地图点状符号及注记的自动配置   总被引：4，自引：1，他引：4  

游涟  何宏星 《测绘学报》1993,22(4):304-308

地图点状符号及注记的配置是自动制图综合及绘制中的一个普遍而困难的问题。本文针这一自动配置问题，研究出了软件模块，在一个具有大量点状符号和注记的实用区域地学数据库－黑龙江省库上，进行了较大程度的综合和取舍，对点状符号和注记进行了智能化地配置，取得了比较满意的效果。  相似文献   

Global Landscapes: Teaching Globalization through Responsive Mobile Map Design     

Robert Roth  Stephen Young  Chelsea Nestel  Carl Sack  Brian Davidson  Julia Janicki 《The Professional geographer》2018,70(3):395-411

This article reports on the design and evaluation of Global Madison, a mobile map designed to support teaching and learning about globalization using Madison, Wisconsin, as a situated classroom. Our experience of place increasingly is mediated by mobile devices, opening new opportunities and challenges for research, industry, and education. Despite this rising popularity, few guidelines exist for creating and using mobile maps. Following tenets of user-centered design studies, we conducted two mixed-method evaluations of Global Madison to improve the tool and generate design insights that are potentially transferable to similar mobile mapping contexts: 244 students participated in an online survey after completing the tour and eighteen students were observed in the field. The evaluations generated new design considerations for mobile maps supporting situated learning, include: focus on critical issues that might leave students stranded, append location-based services with traditional mapping, enforce cognitive association between map and landscape, supply a consistent feed of information for new learners, encourage collaborative learning in the landscape, and promote student safety above all else.  相似文献   

Big Data from the Ground Up: Mobile Maps and Geographic Knowledge     

Craig M. Dalton 《The Professional geographer》2018,70(1):157-164

Consumer users of maps on mobile devices are producing noteworthy geographic knowledges in the contexts of their own lives that are distinct from those of professional data scientists. By leveraging the streaming nature of big data in mobile maps and zooming multiscalar views, consumer users' mobile map practices produce a popular, multiscalar form of visual geographic knowledge that is both enabled and limited by its big data assemblage and associated technologies. The first half of this article outlines the role of consumer user practices amidst spatial big data assemblages, not for volunteered geographic information or aggregate analysis but for contextual, everyday use. Consumer users and their knowledges are coconstituted through mobile map viewing and as materially limited technological practices. This article focuses specifically on the consumer users' concept of scale in this context, for Web-based maps' multiscalar views differentiate them from older maps. The second half analyzes mobile map consumer users' concepts of scale in a series of focus groups that involved both questions and observing participants' actions with maps on their own phones. Instead of passively accepting maps at predetermined optimized scales from the map application, consumer users actively viewed the map across scales while searching but not while navigating.  相似文献   

地图综合中建筑物方向的计算方法及适用性分析     

张燕  ;邓敏  ;李志林 《测绘软科学研究》2008,(2):58-64

建筑物的方向是地图综合过程中的一个基本约束,目前仍没有一个计算建筑物方向的统一方法。本文详细阐述了五种常用的计算方法,分别为最长边法、加权平分线法、统计加权法、最小MBR法和基于墙的均值法。并从其基本原理出发,分析了这五种方法的适用性和局限性。通过两个实验设计和实现,进一步例证了这些方法的适用情况和存在的问题,并发现最小MBR方法较为稳健。  相似文献   

DLG空间要素网格综合法研究     

白建荣  于洪伟 《东北测绘》2008,31(1):74-78

通过将网格法用于DLG空间要素综合的数学计算过程的研究,提出DLG要素综合的一种新方法——网格综合法。通过对点、线、面要素网格综合法的系统分析,重点论述线、面典型空间要素的网格综合法的理论和方法,并提出数学模型,为空间要素自动地综合提出一种有效的技术途径,这在各级地理信息空间数据采集和建库中具有重要意义。  相似文献   

基于多种机器学习模型的西北地区蒸散发模拟与趋势分析          下载免费PDF全文

季鹏  袁星 《大气科学学报》2023,46(1):69-81

基于机器学习方法和多源数据构建高精度蒸散发（Evapotranspiration,ET）产品对研究气候变化背景下干旱、半干旱地区陆地水循环变化具有重要意义。本文利用西北地区12个草地通量站点与卫星遥感产品,基于随机森林、极端梯度提升、支持向量回归和人工神经网络4种机器学习方法构建ET估算模型,制作5 km分辨率ET产品,并分析ET的长期变化趋势。交叉验证结果表明,4种模型的均方根误差都低于0.57 mm·d^-1,R²高达0.73～0.88。SHAP （SHapley Additive exPlanation）可解释性分析表明,4种模型均将净辐射、植被和土壤湿度作为ET估算的重要因子,也能刻画出土壤偏干时土壤水分对ET的限制作用,有较好的物理解释性。多模型集合的ET结果相比单一机器学习模型以及现有遥感产品误差分别降低7％～20％和45％～70％。趋势分析结果显示,西北地区非裸地下垫面在2001—2018年间整体呈现ET增加趋势,平均速率为19 mm/（10 a）。在河套平原和内蒙古中部和东北部地区,ET的增长速率超过降水,这可能会进一步加剧这些地区的干旱化。  相似文献   

Shape-adaptive geometric simplification of heterogeneous line datasets     

Timofey E. Samsonov  Olga. P. Yakimova 《International journal of geographical information science》2017,31(8):1485-1520

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Comparison of input data with different spatial resolution in landscape pattern analysis – A case study from northern Latvia     

《Applied geography (Sevenoaks, England)》2017

A suitable spatial scale needs to be selected in geographical and landscape ecological research, and this requires great consideration as different scales have profound effect on derived landscape spatial patterns. Numerous studies have investigated the effects of different scales on landscape metrics using simulated patterns, but few have been conducted to compare different data sources with variable scale for regional- and landscape-scale assessments. Possibly this has occurred because researchers have been prone to use the best available source, a well-known standard, and easiest to use. This study was conducted to assess the impact of input data resolution on values of landscape pattern metrics in four landscapes at scales 1:10 000, 1:50 000 and 1:100 000. The aim was to determine the applicability of three data sources for thematic models in landscape pattern analyses in the Eastern Baltic region. We found that the utility of CORINE Land Cover data for comprehensive structural assessment in mosaic-type landscapes was very limited, as the level of cartographic generalization excluded many small and linear landscape structure elements with potentially high importance for landscape functioning, such as habitat continuity. We also found that actual area harvested using clearcuts was considerably higher than shown in CORINE data, due to clearcuts size being much smaller than the minimum mapping unit. In the light of this, we suggest using data with spatial resolution corresponding to a cartographic scale of at least 1:50 000, in cases when spatial patches have size up to 25 ha.  相似文献   

建构主义理论视域下的地图学理论与地图服务研究     

朵天林 《测绘科学技术学报》2017,34(4)

认知科学是地图学基础理论之一,作为近年来兴起的新思想,建构主义倡导的"知识主动建构"的理念被广泛接受。地图是地理空间环境认知的结果,同时也是认知地理空间环境的工具。建构主义认知理论所倡导的新理念与"互联网+时空大数据"时代地图服务的理念高度吻合。分析了建构主义视域下的地理信息传输和地图认知,提出了以建构主义为指导的地图服务模型。  相似文献   

基于核密度估计的点群密度制图应用研究   总被引：1，自引：0，他引：1  

卢敏  杨柳  王金茵  黄煌  王结臣 《测绘工程》2017,26(4)

随着信息技术的发展,点状专题数据激增,需要突破传统制图方法的表达局限,利用海量点群数据对专题信息进行快速、直观、综合的制图表达。文中以南京市银行的ATM网点数据以及全国KTV营业点分布为制图数据源,探讨了点群数据核密度估计图以及三维核密度曲面图的制作方法,并对其中的关键技术作了深入的研究。研究表明,基于核密度估计的网点密度制图方法,消除了边界分隔对密度计算精度的影响,能更好反映点群数据的空间分布密度、区域差异、动态变化等特征,具备更丰富的表现力。  相似文献