世界航天遥感技术现状、发展趋势及油气遥感应用方向

世界航天遥感技术发展迅速,掌握卫星发射技术和具备卫星发射能力的国家越来越多,其中,高分辨率小型商业卫星和雷达卫星已经成为重要的遥感信息源;高光谱分辨率遥感将是现今和下个世纪的发展方向。本文总结了世界航天遥感技术现状,分析了今后的发展趋势,提出了油气遥感应用的研究方向     

中国西部地区生态环境现状遥感调查

针对“中国西部地区生态环境现状遥感调查”的需要,综合运用景观生态学理论、生态系统服务功能理论、可持续发展理论、遥感和地理信息系统技术,研究中国西部地区生态环境现状遥感数据的处理与集成,开展中国西部地区土地覆被和生态要素结构变化分析、沙漠化和水土流失强度评价、生态脆弱特征及时空分布规律分析、基于遥感调查的生态环境质量评价、基于多时相遥感数据对比的典型区生态环境遥感分析和生态环境变化成因对策分析等综合性的研究,并以量化和可视化的形式系统地反映西部地区生态环境现状及其变化的空间分布、空间统计和空间特征规律。     

Night on Earth: Mapping decadal changes of anthropogenic night light in Asia

The defense meteorological satellite program (DMSP) operational linescan system (OLS) sensors have imaged emitted light from Earth's surface since the 1970s. Temporal overlap in the missions of 5 OLS sensors allows for intercalibration of the annual composites over the past 19 years (Elvidge et al., 2009). The resulting image time series captures a spatiotemporal signature of the growth and evolution of lighted human settlements and development. We use empirical orthogonal function (EOF) analysis and the temporal feature space to characterize and quantify patterns of temporal change in stable night light brightness and spatial extent since 1992. Temporal EOF analysis provides a statistical basis for representing spatially abundant temporal patterns in the image time series as uncorrelated vectors of brightness as a function of time from 1992 to 2009. The variance partition of the eigenvalue spectrum combined with temporal structure of the EOFs and spatial structure of the PCs provides a basis for distinguishing between deterministic multi-year trends and stochastic year-to-year variance. The low order EOFs and principal components (PC) space together discriminate both earlier (1990s) and later (2000s) increases and decreases in brightness. Inverse transformation of these low order dimensions reduces stochastic variance sufficiently so that tri-temporal composites depict potentially deterministic decadal trends. The most pronounced changes occur in Asia. At critical brightness threshold we find an 18% increase in the number of spatially distinct lights and an 80% increase in lighted area in southern and eastern Asia between 1992 and 2009. During this time both China and India experienced a ∼20% increase in number of lights and a ∼270% increase in lighted area – although the timing of the increase is later in China than in India. Throughout Asia a variety of different patterns of brightness increase are apparent in tri-temporal brightness composites – as well as some conspicuous areas of apparently decreasing background luminance and, in many places, intermittent light suggesting development of infrastructure rather than persistently lighted development. Vicarious validation using higher resolution Landsat imagery verifies multiple phases of urban growth in several cities as well as the consistent presence of low DN (<∼15) background luminance for many agricultural areas. Lights also allow us to quantify changes in the size distribution and connectedness of different intensities of development. Over a wide range of brightnesses, the size distributions of spatially contiguous lighted area are consistent with power laws with exponents near −1 as predicted by Zipf's Law for cities. However, the larger lighted segments are much larger than individual cities; they correspond to vast spatial networks of contiguous development (Small et al., 2011).     

Geoinformatics education in China

The paper gives an overview of the current status of education in geoinformatics in China. First, the paper provides a brief introduction to the history of geoinformatics education in China and a general review of the scientific and technological development. It then presents how the development affects the education and training in China. In the paper, universities and institutes in China that can award academic degrees related to geoinformatics are summarized, and undergraduate majors are briefly introduced. Next, the paper reports the work having been done by the national expert group on Surveying and Mapping, including the revision of discipline catalog and guide for graduate education and requirements. A list of typical curricula in geoinformatics education is suggested. Activities on promoting the graduate student exchange platform are presented. Finally, a case study of geoinformatics education in Wuhan University is discussed.     

中国地区SRTM3 DEM高程精度质量评价

为揭示我国SRTM3DEM数据高程精度质量,结合已开展过SRTM3DEM高程精度质量评价工作的局部地区的研究,考虑空间分布情况,选取新疆、辽宁、山东、浙江、海南5个地区的平原、丘陵、盆地、山地等地形区域作为典型研究区,并以1∶5万DEM为假定真值、以1∶25万DEM为参照,通过DEM面误差可视化分析、DEM面误差信息熵模型、中误差模型等方法对SRTM3DEM数据高程精度质量做了分析。计算结果表明我国SRTM3DEM数据高程精度质量受地形影响并存在一定的空间差异性,同时我国范围内SRTM3DEM数据高程精度质量整体上要高于1∶25万DEM。     

基于GIS技术的我国大气可降水量分布研究

利用分布于全国范围内的125个气象探空测站点(每日8:00和20:00)的探空数据,应用数据库编程与GIS技术,对大气可降水量在全国的分布情况进行了分析,得到了2002年全年以及春夏秋冬4个季节(2001年12月和2002年1,2月作为冬季)的平均大气可降水量在全国的分布状况。对数据进行分析可知:在空间上,我国的大气可降水量总体呈东南多,西北及青藏高原地区少的分布状况。同时,由于地形组合状况的特殊性,导致四川盆地、天山北麓等地区的大气可降水量略高于其周围地区;在时间上,夏季的大气可降水量值较高,可达到62mm左右,冬季较少,而春秋季除局部地区外大气可降水量基本持平。     

新疆大地控制网点2000国家大地坐标系成果应用分析

利用GPS相关技术,通过对比,分析了新疆大地控制网点2000国家大地坐标系成果在新疆测绘领域应用情况,验证了相关的数学精度,并提出了相关的应用分析结论。     

Accuracy analysis for SST gravity field model in China

Taking China as the region for test the potential of the new satellite gravity technique, satelliteto-satellite tracking for improving the accuracy of regional gravity field model is studied. With WDM94 as reference, the gravity anomaly residuals of three models, the latest two GRACE global gravity field model (EIGEN_GRACE02S, GGM02S) and EGM96, are computed and compared. The causes for the differences among the residuals of the three models are discussed. The comparison between the residuals shows that in the selected region, EIGEN_GRACE02S or GGM02S is better than EGM96 in lower degree part (less than 110 degree). Additionally, through the analysis of the model gravity anomaly residuals, it is found that some systematic errors with periodical properties exist in the higher degree part of EIGEN and GGM models, the results can also be taken as references in the validation of the SST gravity data.     

China Digital Ocean Prototype System

Abstract

Digital Ocean is a new research domain of Digital Earth. Because of the spatio-temporal, three-dimensional (3D) and intrinsically dynamic nature of ocean data, it is more difficult to make a breakthrough in this domain. The construction of the China Digital Ocean Prototype System (CDOPS) pushes Digital Ocean a step forward from its operation as a mere concept to its achievement as a realistic system. In this paper, the technical framework of the CDOPS is discussed, including its data, function, and application layers. Then, two key technologies are studied in detail that will enable the construction of the 3D ocean environment and the visualization of the ocean model output data. Practical demonstrations show that the CDOPS provides a technical reference for the development of Digital Ocean. This paper is based on an ongoing research project of the development of CDOPS that aims at the facilitation, integration, sharing, accessing, visualization, and use of the ocean data and model computing data from the Digital Earth perspective.     

Populating digital earth: improving access to Chinese remote sensing data for terrestrial applications

Global change has a significant impact on the lives of humankind. Earth observation can help to better understand our earth and cope with global change. With the availability of more reliable environmental data sets, digital earth is becoming a popular way to monitor the Earth and provide information to researchers and decision makers on environment protection, disaster mitigation, and social benefits. Therefore, accessing data with lowering costs is essential for digital earth. Nevertheless, there are big challenges in ensuring the feasibility of access to Chinese remote sensing data. This paper outlines some of the main challenges in realizing data sharing, provides an analysis of the core reasons leading to these challenges, and proposes recommendations to overcome the challenges. Amongst the main challenges are differences in data policy to gain access to satellite data, diverse data formats, and delivery mechanisms. The major challenge for the decision makers is to define a more open policy and for the scientist the challenge is to implement these polices for the benefit of all. This paper proposes that governments should adopt policies encouraging more open distribution and access to their data, in order to generate an improved digital earth with increased benefits to human society.