以我国区域为研究对象,分析了OpenStreetMap土地覆被信息的时空特征。结果表明,该数据在我国东北、华北、西北、华中、东南和西南6个地理分区均呈聚集状态分布,且数量表现出明显的差异性,东南区域是土地覆被信息最为集中的区域,该区域...以我国区域为研究对象,分析了OpenStreetMap土地覆被信息的时空特征。结果表明,该数据在我国东北、华北、西北、华中、东南和西南6个地理分区均呈聚集状态分布,且数量表现出明显的差异性,东南区域是土地覆被信息最为集中的区域,该区域仅占研究区域总面积的5%,却集中了土地覆被信息总量的33%;土地覆被信息以人工地表和水体为主,二者之和约占土地覆被信息总量的80%,其次为林地、草地、耕地,裸地数量最小;随着空间分辨率从30 m升尺度至500 m,各种类别的样本数据均随之减少,但林地、草地及耕地的减少速度明显低于人工地表和水体;年际及月季尺度分析表明,除裸地外,其余5种土地覆被类别均呈现较为显著的增加趋势,这说明Open Street Map数据具有稳定的数据来源,具有较好的现势性,可以形成一定的时间序列。该研究为未来大尺度土地覆被遥感产品生产及验证过程中训练、参考数据的选择,特别是人工地表和水体,提供了一定参考,也为土地覆被遥感产品更新完善提供了有效的数据来源。展开更多
随着Web2.0的高速发展,基于用户创建的地理数据共享平台为广大用户提供了丰富的数据源。这种基于用户的自发地理信息(VGI)受到其数据采集、表达等特点的限制,其数据质量严重影响其进一步地应用。以VGI中较成功的案例——Open Street Map...随着Web2.0的高速发展,基于用户创建的地理数据共享平台为广大用户提供了丰富的数据源。这种基于用户的自发地理信息(VGI)受到其数据采集、表达等特点的限制,其数据质量严重影响其进一步地应用。以VGI中较成功的案例——Open Street Map(OSM)为例,对其路网数据质量和应用进行评价。首先从OSM数据的特点出发,给出了数据长度完整性和道路名称属性完整性2个定量质量要素的描述方法;其次选取国内外大、中、小4个城市做为实验区,与Baidu地图、Google地图的路网数据从长度和道路名称属性完整性进行比较、分析;最终通过实验结果表明,与Baidu地图相比,OSM的路网数据完整性和现势性在国内的3个城市整体上相当,但在国外具有较明显的优势,如果对其做进一步的处理,可以作为Baidu地图在海外电子地图的路网数据,进一步提高其应用价值。展开更多
Geographical studies of outdoor activities have increased in recent years with the rise in popularity of these activities worldwide,including in Japan.Volunteered geographic information(VGI)is a key tool for organizin...Geographical studies of outdoor activities have increased in recent years with the rise in popularity of these activities worldwide,including in Japan.Volunteered geographic information(VGI)is a key tool for organizing outdoor activities as it offers a means to determine the locational information and names of places.To evaluate the quality of VGI,geospatial data generated by land survey agencies and other VGI are often utilized as reference data.However,since these reference data may not be available,other methods are necessary to assure the quality of VGI.In this study,we examined five trust indicators based on the inherent characteristics of VGI through an empirical case study.We used mountain names extracted from OpenStreetMap in Japan as data because there were almost no other VGI in the vicinity.As a result,we isolated three trust indicators,namely versions,users,and tag corrections,to examine the thematic accuracy of VGI because these were the only statistically significant indicators.However,we found that the prediction rate of thematic accuracy was very low.To improve thematic accuracy,this study recommends using the most accurate versions,applying correctly given tags,and considering the motivations and characteristics of the VGI contributors.展开更多
The crowdsourced OpenStreetMap mapping platform is utilized by countless stakeholders worldwide for various purposes and applications.Individuals,researchers,governments,commercial,and humanitarian organizations,in ad...The crowdsourced OpenStreetMap mapping platform is utilized by countless stakeholders worldwide for various purposes and applications.Individuals,researchers,governments,commercial,and humanitarian organizations,in addition to the engineers,professionals,and technical developers,use OpenStreetMap both as data contributors and consumers.The storage,usage,and integration of volunteered geographical data in software applications often create complex ethical dilemmas and values regarding the relationships between different categories of stakeholders.It is therefore common for moral preferences of stakeholders to be neglected.This paper investigates the integration of ethical values in OpenStreetMap using the value sensitive design methodology that examines technical,empirical,and conceptual aspects at each design stage.We use the Humanitarian OpenStreetMap Team,an existing volunteered geographic information initiative,as a case study.Our investigation shows that although OpenStreetMap does integrate ethical values in its organizational structure,a deeper understanding of its direct and indirect stakeholders’perspectives is still required.This study is expected to assist organizations that contribute to or use OpenStreetMap in recognizing and preserving existing and important ethical values.To the best of our knowledge,this is the first attempt to evaluate ethical values methodically and comprehensively in the design process of the OpenStreetMap platform.展开更多
文摘以我国区域为研究对象,分析了OpenStreetMap土地覆被信息的时空特征。结果表明,该数据在我国东北、华北、西北、华中、东南和西南6个地理分区均呈聚集状态分布,且数量表现出明显的差异性,东南区域是土地覆被信息最为集中的区域,该区域仅占研究区域总面积的5%,却集中了土地覆被信息总量的33%;土地覆被信息以人工地表和水体为主,二者之和约占土地覆被信息总量的80%,其次为林地、草地、耕地,裸地数量最小;随着空间分辨率从30 m升尺度至500 m,各种类别的样本数据均随之减少,但林地、草地及耕地的减少速度明显低于人工地表和水体;年际及月季尺度分析表明,除裸地外,其余5种土地覆被类别均呈现较为显著的增加趋势,这说明Open Street Map数据具有稳定的数据来源,具有较好的现势性,可以形成一定的时间序列。该研究为未来大尺度土地覆被遥感产品生产及验证过程中训练、参考数据的选择,特别是人工地表和水体,提供了一定参考,也为土地覆被遥感产品更新完善提供了有效的数据来源。
文摘随着Web2.0的高速发展,基于用户创建的地理数据共享平台为广大用户提供了丰富的数据源。这种基于用户的自发地理信息(VGI)受到其数据采集、表达等特点的限制,其数据质量严重影响其进一步地应用。以VGI中较成功的案例——Open Street Map(OSM)为例,对其路网数据质量和应用进行评价。首先从OSM数据的特点出发,给出了数据长度完整性和道路名称属性完整性2个定量质量要素的描述方法;其次选取国内外大、中、小4个城市做为实验区,与Baidu地图、Google地图的路网数据从长度和道路名称属性完整性进行比较、分析;最终通过实验结果表明,与Baidu地图相比,OSM的路网数据完整性和现势性在国内的3个城市整体上相当,但在国外具有较明显的优势,如果对其做进一步的处理,可以作为Baidu地图在海外电子地图的路网数据,进一步提高其应用价值。
文摘Geographical studies of outdoor activities have increased in recent years with the rise in popularity of these activities worldwide,including in Japan.Volunteered geographic information(VGI)is a key tool for organizing outdoor activities as it offers a means to determine the locational information and names of places.To evaluate the quality of VGI,geospatial data generated by land survey agencies and other VGI are often utilized as reference data.However,since these reference data may not be available,other methods are necessary to assure the quality of VGI.In this study,we examined five trust indicators based on the inherent characteristics of VGI through an empirical case study.We used mountain names extracted from OpenStreetMap in Japan as data because there were almost no other VGI in the vicinity.As a result,we isolated three trust indicators,namely versions,users,and tag corrections,to examine the thematic accuracy of VGI because these were the only statistically significant indicators.However,we found that the prediction rate of thematic accuracy was very low.To improve thematic accuracy,this study recommends using the most accurate versions,applying correctly given tags,and considering the motivations and characteristics of the VGI contributors.
文摘The crowdsourced OpenStreetMap mapping platform is utilized by countless stakeholders worldwide for various purposes and applications.Individuals,researchers,governments,commercial,and humanitarian organizations,in addition to the engineers,professionals,and technical developers,use OpenStreetMap both as data contributors and consumers.The storage,usage,and integration of volunteered geographical data in software applications often create complex ethical dilemmas and values regarding the relationships between different categories of stakeholders.It is therefore common for moral preferences of stakeholders to be neglected.This paper investigates the integration of ethical values in OpenStreetMap using the value sensitive design methodology that examines technical,empirical,and conceptual aspects at each design stage.We use the Humanitarian OpenStreetMap Team,an existing volunteered geographic information initiative,as a case study.Our investigation shows that although OpenStreetMap does integrate ethical values in its organizational structure,a deeper understanding of its direct and indirect stakeholders’perspectives is still required.This study is expected to assist organizations that contribute to or use OpenStreetMap in recognizing and preserving existing and important ethical values.To the best of our knowledge,this is the first attempt to evaluate ethical values methodically and comprehensively in the design process of the OpenStreetMap platform.
