检索结果-南通市图书馆

Assimilating ASAR Data for Estimating Soil Moisture Profile Using an Ensemble Kalman Filter

Chinese Geographical Science 2013年第6期23卷 666-679页

作者： YU Fan LI Haitao GU Haiyan HAN Yanshun Key Laboratory of Geo-Informatics of State Bureau of surveying and mapping Chinese Academy of Surveying and Mapping

Active microwave remote sensing data were used to calculate the near-surface soil moisture in the vegetated *** this study,Advanced Synthetic Aperture Radar(ASAR)observations of surface soil moisture content were used in a data assimilation framework to improve the estimation of the soil moisture profile at the middle reaches of the Heihe River Basin,Northwest China.A one-dimensional soil moisture assimilation system based on the ensemble Kalman filter(EnKF),the forward radiative transfer model,crop model,and the Distributed Hydrology-Soil-Vegetation Model(DHSVM)was *** crop model,as a semi-empirical model,was used to estimate the surface backscattering of vegetated *** DHSVM is a distributed hydrology-vegetation model that explicitly represents the effects of topography and vegetation on water fluxes through the *** experiments were conducted to assimilate the ASAR data into the DHSVM and in situ soil moisture at the middle reaches of the Heihe River Basin from June20 to July 15,*** results indicated that EnKF is effective for assimilating ASAR observations into the hydrological *** with the simulation and in situ observations,the assimilated results were significantly improved in the surface layer and root layer,and the soil moisture varied slightly in the deep ***,EnKF is an efficient approach to handle the strongly nonlinear problem which is practical and effective for soil moisture estimation by assimilation of remote sensing ***,to improve the assimilation results,further studies on obtaining more reliable forcing data and model parameters and increasing the efficiency and accuracy of the remote sensing observations are needed,also improving estimation accuracy of model operator is important.

关键词： assimilation ensemble Kalman filter (EnKF) soil moisture hydrological model Advanced Synthetic Aperture Radar(ASAR)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The concept, key technologies and applications of temporal-spatial information infrastructure

引用

Geo-Spatial Information Science 2016年第2期19卷中插6-中插6,148-156页

作者： Chengming Li Po Liu Jie Yin Xiaoli Liu Chinese academy of surveying and mapping BeijingChina

Smart city is the development of digital city; as its main supporting technology, the digital city geo-spatial framework has to be upgraded to the temporal-spatial information infrastructure (TSII). first, this paper proposes the concept and basic framework of smart city and defines the concept of TSII - processes, integration, mining analysis, and share time-stamps geographic data - and the related policy, regulations and standards, technology, facilities, mechanism, and human resources. The framework has four components: the benchmark of time and space, temporal-spatial big data, the cloud service platform and the related supporting environment. Second, the temporal-spatial big data and cloud service platform are elaborated. finally, an application of TSII constructed by the Xicheng District Planning Bureau in Beijing is introduced, which provides a useful reference for the construction of smart city.

关键词： Smart city temporal-spatial information infrastructure cloud platform big data data mining

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Technical progress of China’s national remote sensing mapping:from mapping western China to national dynamic mapping

引用

Geo-Spatial Information Science 2021年第1期24卷 121-133,I0013页

作者： Jixian Zhang Haiyan Gu Wei Hou Chunquan Cheng National Quality Inspection and Testing Center for surveying and mapping Products State BeijingChina Chinese academy of surveying and mapping BeijingChina

Remote sensing mapping is an important research direction in the development of geographic surveying and *** order to successfully implement the project of mapping Western China(MWC),a technical mapping system has been *** this project,many problems have been solved through technological innovation,such as block adjustment with scarce control points,large-scale aerial/satellite image mapping,and intelligent interpretation of multi-source *** softwares were developed,*** for aerial/satellite image mapping in a large area,FeatureStation for the integration of multi-source data in the complex terrain areas,and an airborne multi-band and multi-polarization interferometric data acquisition system for SAR *** the first time,full coverage of 1:50,000 topographic data of China’s land territory has been produced,which means the geospatial framework of digital China is basically *** the implementation of other key national plans and projects(*** geographic conditions monitoring and national remote sensing mapping),the focus has changed from MWC to national dynamic ***,a dynamic mapping system is *** data acquisition capability has developed from a single source to multiple sources and multiple *** mapping capability has developed into dynamic mapping,and the capability for database update shows the characteristics of *** national geographic condition monitoring creates a multi-scale index system for statistical analysis for various needs.A multi-level and multi-dimensional technical system for statistical computing and decision-making service is developed for the transformation from dynamic monitoring to information *** this paper,we give a brief introduction about the recent development of remote sensing mapping in China with respect to data acquisition,map production,and information *** purpose of this paper is to motivate the establishment

关键词： Remote sensing mapping mapping western China national dynamic monitoring data acquisition image interpretation information service

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Understanding geographical conditions monitoring: a perspective from China

引用

International Journal of Digital Earth 2015年第1期8卷 38-57页

作者： Jixian Zhang Weisen Li Liang Zhai Chinese academy of surveying and mapping BeijingChina National Administration of surveying Mapping and Geo-informationBeijingChina

The geographical condition is a very important component of a country’s national condition,and geographical conditions monitoring(GCM)has been of great concern to the Chinese *** has a close relation with‘Digital China’and is a concrete embodiment of Digital *** paper discusses the content and classification of *** accordance with application areas,GCM can be divided into fundamental monitoring,thematic monitoring,and disaster *** application areas perspective includes the content of the three other perspectives,like the monitoring elements,the monitoring scope,and the monitoring cycle and fully reflects the essence of the *** monitoring mainly focuses on monitoring all of the geographical elements,which provides a basis for follow-up thematic monitoring;thematic monitoring is a special type of designated subject monitoring that concerns the public or the government;disaster monitoring focuses on the dynamic monitoring of the pre-disaster and disaster periods for natural *** monitoring results will provide timely information for governments so that they can meet management or decision-making requirements.A GCM case study in the area of the Qinghai−Tibet plateau was made,and some concrete conclusions were ***,this paper presents some thoughts on conducting GCM.

关键词： geographical conditions monitoring fundamental monitoring thematic monitoring disaster monitoring Qinghai−Tibet plateau

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Uncertainty of Slope Length Derived from Digital Elevation Models of the Loess Plateau, China

引用

Journal of Mountain Science 2014年第5期11卷 1169-1181页

作者： ZHU Shi-jie TANG Guo-an XIONG Li-yang ZHANG Gang Key Laboratory of Virtual Geographic Environment Ministry of Education Nanjing Normal University zhejiang academy of surveying & mapping

Although many studies have investigated slope gradient uncertainty derived from Digital Elevation Models(DEMs), the research concerning slope length uncertainty is far from mature. This discrepancy affects the availability and accuracy of soil erosion as well as hydrological modeling. This study investigates the formation and distribution of existing errors and uncertainties in slope length derivation based on 5-m resolution DEMs of the Loess Plateau in the middle of China. The slope length accuracy in three different landform areas is examined to analyse algorithm effects. The experiments indicate that the accuracy of the flat test area is lower than that of the rougher areas. The value from the specific contributing area(SCA) method is greater than the cumulative slope length(CSL), and the differences between these two methods arise from the shape of the upslope area. The variation of mean slope length derived from various DEM resolutions and landforms. The slope length accuracy decreases with increasing grid size and terrain complexity at the six test sites. A regression model is built to express the relationship of mean slope length with DEM resolution less than 85 m and terrain complexity represented by gully density. The results support the understanding of the slope length accuracy, thereby aiding in the effective evaluation of the modeling effect of surface process.

关键词： Slope length Uncertainty Digital Elevation Models(DEM) Loess terrain

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Multi-component Decomposition Method for Polarimetric SAR Data

引用

Chinese Journal of Electronics 2017年第1期26卷 205-210页

作者： WEI Jujie ZHAO Zheng YU Xiaoping LU Lijun Chinese academy of surveying and mapping Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences

There are more unknowns than equations to solve for previous four-component decomposition methods. So they have to determine each scattering power with some assumptions and avoid negative powers in decomposed results with physical power *** paper presents a multi-component decomposition for multi-look Polarimetric SAR(Pol SAR) data by combining the Generalized similarity parameter(GSP) and the eigenvalue decomposition. It extends the existing fourcomponent decomposition by adding the diffuse scattering as the fifth scattering component considering additional cross-polarized power that could represent terrain effects and rough surface scattering. And unlike the previous methods, the new method determines the volume scattering contribution by a modified nonnegative eigenvalue decomposition method and utilizes the GSP to determine the negative powers of the three scattering contributions(i.e., odd-bounce, double-bounce, and diffuse scattering)directly without extra assumptions and constraints. By experiment, the new method is proved to be more straightforward and reasonable.

关键词： Multi-component decomposition Polarimetric SAR(PolSAR) Generalized similarity parameter(GSP)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The trend of the APRGP velocity field and plates movement derived from GPS data

引用

Science China(Physics,Mechanics & Astronomy) 2010年第4期53卷 767-772页

作者： CHENG PengFei , WANG Hua, CHENG YingYan, WEN HanJiang & CAI YanHui Chinese academy of surveying and mapping, Beijing 100039, China 1. Chinese academy of surveying and mapping Beijing 100039 China

High-precision data processing theories and methods for the wide area GPS network–––Asia Pacific Regional Geodesy Project (APRGP), are systematically discussed in this article. With the software bernese5.0 update, the annual results of APRGP coordinate, velocity field and the trend of plate movement are reestimated, and the corresponding accuracy of adjustment with different constraints, also the velocity field of APRGP, are presented and analyzed. Conclusions could be drawn that Eurasian plate (EURA) rotates clockwise, the Australian plate (AUST) and the Indian plate (INDI) move from southwest to northeast, while the Pacific plate (PCFC) is drifting to northwest, which shows agreement with those of IGS results.

关键词： APRGP Bernese5.0 GPS Data processing velocity field plate movement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

ANALYSIS OF SPECTRAL CHARACTERISTICS AMONG DIFFERENT SENSORS BY USE OF SIMULATED RS IMAGES

引用

Geo-Spatial Information Science 2000年第2期3卷 35-40页

作者： YE Zetian GU Xingfa LIU Xianlin WANG Zhimin Chinese academy of surveying and mapping

This research,by use of RS image_simulating method,simulated apparent reflectance images at sensor level and ground_reflectance images of SPOT_HRV,CBERS_CCD,Landsat_TM and NOAA14_AVHRR’s corresponding *** images were used to analyze sensor’s differences caused by spectral sensitivity and atmospheric *** differences were analyzed on Normalized Difference Vegetation Index(NDVI).The results showed that the differences of sensors’ spectral characteristics cause changes of their NDVI and *** multiple sensors’ data are applied to digital analysis,the error should be taken into *** effect makes NDVI smaller,and atmospheric correction has the tendency of increasing NDVI *** reflectance and their NDVIs of different sensors can be used to analyze the differences among sensor’s *** spectral analysis method based on RS simulated images can provide a new way to design the spectral characteristics of new sensors.

关键词： simulated RS image sensor spectral characteristics vegetation index analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

From Physical Space to Visual Image Space

引用

Geo-Spatial Information Science 2003年第2期6卷 42-47页

作者： YE Zetian LIN Hui LIU Xianlin YE Zetian, Ph.D, Chinese academy of surveying and mapping, 16 Beitaiping Road, Haidian District, Beijing 100039, China. Chinese academy of surveying and mapping

The theoretical framework of visual simulation in virtual reality is discussed. The new concept of visual image space is supposed. On the basis of visual image space, in visual perceptive sense, VR is considered as a spatial simulation. The objective of the spatial simulation is to transform physical space to visual image space. Last, the prototype system, surveying & mapping virtual Reality (SMVR), is developed, and the space simulation above is realized. By use of SMVR, the real 3D representation, 3D visual analysis, virtual plan and designs can be implemented.

关键词： virtual reality physical space visual image space space of earth surface space simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Overview of the key technologies for high-resolution satellite mapping

引用

International Journal of Digital Earth 2012年第3期5卷 228-240页

作者： Xinming Tang Junfeng Xie Satellite surveying and mapping Application Center State Bureau of Surveying and MappingBeijingPR China

As the important infrastructures for land mapping and resource monitoring,highresolution remote sensing satellites(HRSS)are urgently demanded for the development of *** this article,the key technologies of the main HRSS are summarized,and these technologies include sensor design,attitude and orbit determination,geometric calibration,imaging model construction,and block adjustment,etc.,which involve the mapping accuracy of ***,the system design of the ZY-3 Satellite(China’s first civil stereoscopic surveying and mapping satellite,to be launched in 2012)is introduced,which mainly include satellite technical specifications and strategies design based on these key technologies research.

关键词： high-resolution remote sensing satellite satellite technical specifications satellite surveying and mapping ZY-3 Satellite

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：