融合三边测量和PDR的室内定位关键技术分析及应用

随着无线室内定位技术的发展,室内定位效果有了明显提升,但仅采用无线定位方法,定位点跳动频繁,定位效果较差,难以获取连续位置的准确定位。实际应用中不同的硬件平台也会影响具体定位方法的选择,通常需采用多种技术手段的组合以达到理想定位效果。本文基于微信公众平台的服务需要,提出了一种基于三边测量定位和步行者航位推算（PDR）融合的室内定位方法,通过地图信息匹配纠正定位结果,得到连续稳定的定位结果;并集成室内地图可视化技术,研发了一套基于微信平台的三维室内定位系统,在实际工程场景中进行应用,具有较好的定位效果。     

面向数字孪生城市的智能化全息测绘

以大数据、物联网、人工智能、虚拟现实、云计算、智能驾驶等新技术为代表的信息化浪潮席卷全球,数字世界与物理世界正形成两大平行发展、相互作用的体系,数字孪生技术应运而生。随着物联网技术（IOT）的发展,数字孪生的理念被引入到智慧城市建设中来,深刻影响着城市规划、建设与治理。笔者所在单位面向数字孪生城市和自然资源统一监管对测绘地理信息的新需求,在全国开创性地开展了面向数字孪生城市的智能化全息测绘试点工作。本文结合上海市智能化全息测绘试点工作,从数字孪生城市、数字孪生城市对地理信息的新需求、智能化全息测绘关键技术及测绘成果等方面展开了论述,重点介绍了智能化全息测绘的技术体系和产品体系,以及在社会各领域的应用成果。     

论万物互联时代的地球空间信息学

随着5G/6G、云计算、物联网和人工智能等新技术的发展,人类已经进入了万物互联时代。本文探讨万物互联时代地球空间信息技术的五大特点：定位技术从GNSS和地面测量走向无所不在的定位导航定时（PNT）服务体系;遥感技术从孤立的遥感卫星走向空天地传感网络;地理信息服务从地图数据库为主走向真三维实景和数字孪生;3S集成从移动测量发展到智能机器人服务;学科研究范围从对地观测走向物联监测和对人类活动的感知。笔者基于这些特点进一步剖析新时代面临的挑战,并提出新时代地球空间信息学发展亟待解决的三大科学技术问题：测绘学科如何服务人与机器人的共同需求？遥感影像解译的机理是什么和如何突破实现技术的瓶颈？如何利用时空大数据挖掘人与自然的关系,从空间感知走向空间认知？万物互联时代的地球空间信息学,必须且完全可能为万物互联的数字地球和智慧社会做出更大的贡献！     

RESEARCH ON AUTOMATIC FOG IDENTIFICATION TECHNOLOGY BY METEOROLOGICAL SATELLITE REMOTE SENSING

There is an urgent need for the development of a method that can undertake rapid, effective, and accurate monitoring and identification of fog by satellite remote sensing, since heavy fog can cause enormous disasters to China’s national economy and people's lives and property in the urban and coastal areas. In this paper, the correlative relationship between the reflectivity of land surface and clouds in different time phases is found, based on the analysis of the radiative and satellite-based spectral characteristics of fog. Through calculation and analyses of the relative variability of the reflectivity in the images, the threshold to identify quasi-fog areas is generated automatically. Furthermore, using the technique of quick image run-length encoding, and in combination with such practical methods as analyzing texture and shape fractures, smoothness, and template characteristics, the automatic identification of fog and fog-cloud separation using meteorological satellite remote sensing images are studied, with good results in application.     

Evaluating the Tree Population Density and Its Impacts in CLM-DGVM

Vegetation population dynamics play an essential role in shaping the structure and function of terrestrial ecosystems.However,large uncertainties remain in the parameterizations of population dynamics in current Dynamic Global Vegetation Models(DGVMs).In this study,the global distribution and probability density functions of tree population densities in the revised Community Land Model-Dynamic Global Vegetation Model(CLM-DGVM) were evaluated,and the impacts of population densities on ecosystem characteristics were investigated.The results showed that the model predicted unrealistically high population density with small individual size of tree PFTs(Plant Functional Types) in boreal forests,as well as peripheral areas of tropical and temperate forests.Such biases then led to the underestimation of forest carbon storage and incorrect carbon allocation among plant leaves,stems and root pools,and hence predicted shorter time scales for the building/recovering of mature forests.These results imply that further improvements in the parameterizations of population dynamics in the model are needed in order for the model to correctly represent the response of ecosystems to climate change.     

美国NCEP/NCAR全球再分析资料及其初步分析

对美国国家环境预测中心（ＮＣＥＰ）及国家大气研究中心（ＮＣＡＲ）的４０年全球再分析资料在中国应用的可信度进行了初步分析,其中包括温、压、风、湿、降雨量、地面辐射、地面感热、地面蒸发潜热及青藏高原地面热源等。除降水量再分析资料与气候资料的比较属同一时段外,其余均属非同一时段比较。两者基本特征和分布形势一致,再分析资料比较合理。     

长江、黄河大洪水前期地球系统演变的分析

通过分析江、淮、黄、海四大洪共１４个大洪水年的前期地震场特征,发现大洪水前在青藏高原东南地区、亚欧中纬地带和台湾以东洋面三处的有强地震发生,若强震出现在中印缅热点则对应着江淮大小;强震出现在川青甘地区则对应着黄海河大水。引发大水的直接原因是本地区地热涡的强烈发展,它因刚好位于数组”同向等距地热涡族”的相交点上,交相干共振的结果,文中详细分析了１９５４和１９８２年两个个例。最后分析了“中印缅热点”的     

Simulation of quasi-linear mesoscale convective systems in northern China: Lightning activities and storm structure

Two intense quasi-linear mesoscale convective systems(QLMCSs) in northern China were simulated using the WRF(Weather Research and Forecasting) model and the 3D-Var(three-dimensional variational) analysis system of the ARPS(Advanced Regional Prediction System) model.A new method in which the lightning density is calculated using both the precipitation and non-precipitation ice mass was developed to reveal the relationship between the lightning activities and QLMCS structures.Results indicate that,compared with calculating the results using two previous methods,the lightning density calculated using the new method presented in this study is in better accordance with observations.Based on the calculated lightning densities using the new method,it was found that most lightning activity was initiated on the right side and at the front of the QLMCSs,where the surface wind field converged intensely.The CAPE was much stronger ahead of the southeastward progressing QLMCS than to the back it,and their lightning events mainly occurred in regions with a large gradient of CAPE.Comparisons between lightning and non-lightning regions indicated that lightning regions featured more intense ascending motion than non-lightning regions;the vertical ranges of maximum reflectivity between lightning and non-lightning regions were very different;and the ice mixing ratio featured no significant differences between the lightning and non-lightning regions.     

1951—2009年中国不同区域气温和降水量变化特征

为了研究中国不同区域气候变化特征,将全国按照气候区域划分为11个气候区,并利用1951—2009年中国194个国家基本/基准站月、年气温和降水观测资料,对全国及每个气候区平均温度及降水量的年和季节变化特征进行分析。结果表明：中国及各地区增温趋势均为极显著增加,尤其近20 a增温速度更快;而2007年成为有记录以来最暖的一年;中国冬季平均温度上升趋势最明显,春季次之,夏季几乎没有变化。中国平均年总降水量20世纪50年代最多,2000年代最少;而华北地区的年降水量减少最快;在四季降水中,中国只有夏季降水量波动略有增加,且各区域降水分布具有明显的南北差异特征。     

霾观测判识标准定量化对雾霾观测记录的影响

为研究霾观测判识标准定量化对雾霾观测记录的影响,选取2006—2012年湖北省18个基准站、基本站和一般站三类国家级地面气象观测站的资料,对已记录和按照相对湿度判识标准统计的雾、轻雾和霾天数进行分析,结果表明:判识标准定量化将使霾的观测记录明显增多,轻雾和雾观测记录略有减少,霾和轻雾观测记录将更趋合理,就湖北省而言,相对湿度在80%~95%之间,应以轻雾和雾为主;通过定时观测时次的能见度、相对湿度,以及日天气现象记录,可以得到历年按照相对湿度判识标准统计的霾和轻雾天数,实现对历史资料序列的订正,形成判识标准改变前后均一化的月年资料序列。判识标准定量化后,不能机械的硬套判识指标,观测员仍需熟练掌握轻雾和霾以及其他视程障碍现象的成因和特征,避免相对湿度在霾观测判识标准上下波动、轻雾处于消散过程阶段,轻雾与霾的频繁转记。