A FRAMEWORK FOR AUTOMATED CHANGE DETECTION SYSTEM

1Ｃｕｒｒｅｎｔｃｈａｎｇｅｄｅｔｅｃｔｉｏｎｔｅｃｈ ｎｉｑｕｅｓＡｕｔｏｍａｔｉｃｃｈａｎｇｅｄｅｔｅｃｔｉｏｎｉｎｉｍａｇｅｓｏｆａｇｉｖｅｎｓｃｅｎｅａｃｑｕｉｒｅｄａｔｄｉｆｆｅｒｅｎｔｔｉｍｅｓｉｓｏｎｅｏｆｔｈｅｍｏｓｔｉｎｔｅｒｅｓｔｉｎｇｔｏｐｉｃｓｏｆｉｍａｇｅｐｒｏｃｅｓｓｉｎｇ .Ｉｔｆｉｎｄｓｉｍ ｐｏｒｔａｎｔａｐｐｌｉｃａｔｉｏｎｓｗｉｔｈｉｎｄｉｆｆｅｒｅｎｔｃｏｎｔｅｘｔｓ,ｒａｎｇ ｉｎｇｆｒｏｍｖｉｓｕａｌｓｕｒｖｅｉｌｌａｎｃｅａｎｄｖｉｄｅｏｃｏｄｉｎｇｔｏｔ…     

GeoML~(TM)——地理空间信息共享和互操作模式研究

数字地球为下一代全球信息基础设施建设展示了美好的前景 ,而研究地理空间信息共享与互操作模式正在成为数字地球关键技术的前沿。基于 Open GIS规范和 XML 标准 ,提出了基于 Internet的地理空间对象标识语言Geo MLTM,探讨了可实现在 Internet上传输显示电子地图的 Geo ML 标准规范内容 ,并具体设计和试验了可在Internet上运行的该标准规范的原型系统 ,初步达到了地理空间信息在 Internet/ Intranet上的发布、共享和互操作的目的。     

The stochastic estimation of satellite clock correction information in WADGPS

1 IntroductionChnventional DGPS is limited by the range overwhich the differential corrections are valid due tothe rapid decorrelation of the error sources with in-creasing distance from the reference station to user.In wide area differential GPS (WWPS) errorsources in GPS measurements are medeled sepa-rately,on the basis of a limited number of referencestaitOns, to overcome this drawback. The main er-ror sources are regarded as broadcast ephemeris er-ror,atmospheric refraction and satel…     

Palaeoseismic records in lacustrine sediments—A case study of the Daqingshan piedmont fault and Hasuhai Lake in Inner Mongolia,China

As a traditional method for palaeoseismic studies, trenching can be combined with dating techniques to identify palaeoseismic events and the earthquake recurrence interval. However, when using trenches to study palaeoearthquakes, factors such as the active tectonic background of the earthquake‐caused structure, the lithology on both sides of the fault, the geomorphology location and type and the samples and methods for dating will affect the location of the trench. Thus, trenches should be carefully selected and used to identify the impact of ancient earthquakes. The results have substantial uncertainties and limitations. In recent years, scholars have made considerable progress in using other methods to reveal the palaeoseismic information of faults. Moreover, the history of fault activity may have been recorded in the lacustrine sediment adjacent to the fault. Hasuhai Lake is adjacent to the middle segment of the Daqingshan piedmont fault in Inner Mongolia. Since the Holocene, the region has experienced a temperate continental semi‐arid climate with little interference, and Hasuhai Lake and peripheral waters present weak hydrodynamic conditions that provide an ideal location for the study of palaeoseismic records in lacustrine sediments. Sediment samples and samples for dating were collected from three trenches excavated on the periphery of the Hasuhai Lake. Their variations in grain size and magnetic susceptibility revealed that wind and flowing water jointly produced the sedimentary conditions of Hasuhai sediments. The ¹⁴C dating results and variations in the grain size distribution, grain size components and magnetic susceptibility of sediments caused by seismic events obtained in this study were compared with those caused by a series of palaeoseismic events at the middle segment of the Daqingshan piedmont fault reported by previous studies using trenches, knickpoints and palaeosol records. The results identified seven palaeoseismic events recorded near Hasuhai Lake since 12,000 years. The combined use of lacustrine sediment variation characteristics and dating techniques is an effective method for studying palaeoseismic events.     

青土湖近6000年来沉积气候记录研究--兼论四五世纪气候回暖

对青土湖志云村剖面沉积气候记录和湖泊进退进行了研究,证实季风边缘区河西走廓东段存在暖湿,冷干气候变化的阶段性特征。根据湖相沉积的颜色,粒度,化学组成和有机质含量等气候代用指标的综合分析,提出公元四五世纪存在一次百年尺度上的气候回暖,这一气候回暖事件的发现,可得到历史文献记录和青海湖自然记录的佐证。     

Influence of a spatial structure of precipitates on polarization characteristics of the outgoing microwave radiation of the atmosphere

Issues of the formation and recording of the spatial and angular distributions of thermal radio radiation of rainfall in the microwave range are discussed. The thermal radio-frequency radiative transfer in a threedimensional rain cell is simulated numerically with a different rainfall rate, taking into account the nonspherical shape of falling raindrops and their size distribution. The role of the three-dimensional inhomogeneity of rainfall fields in the formation of a field of their inherent thermal radio radiation in the microwave range is revealed.