Key Words: urban entity, urban expansion, RS, Shannon entropy, Beijing The design and implementation of address matching engine

CHEN Xu*a,b , LI Qing-yuana, WANG Yonga

a Chinese Academy of Surveying and Mapping, Beijing 100039, China;

bLiaoning Technical University, Fuxin 123000, China

In real life there are various types of information, not all information contains a clear geographical coordinates of the spatial information, a large portion of non-spatial information is relevant to space location, such as address, ID card number, telephone number, postcode, and so on, such information does not directly contain spatial coordinates, but implicit location information. In this paper, a engine, which natural language matches address, based on the word segmentation technology has been put forward. The engine can extract address name, ID card number, telephone number information from natural language and convert them to a clear geographical coordinates or the bounds of geographical coordinates. It will be the vital link between non-spatial information and spatial information.

WANG Xiu-lan∗a,b, LI Xue-ruia,b, FENG Zhong-kea,b

a The Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University, 100083, P. R. China;

b Institute of GIS, RS & GPS, Beijing Forestry University, 100083, P. R. China.

Urban fringe lies in the transitional region between urban and rural. Defining the area of urban fringe and the changing situation will be beneficial to the urban planning and the readjustment of land use structure. Taking land sat TM as basic information, using the theories of Shannon entropy and land use degree comprehensive index, methods on how to define the area of urban fringe in Beijing are discussed. Further, the range of urban fringe area in Beijing is found out by using these two methods. It shows that the area of urban fringe in Beijing including a part of the urban district and also a small part of rural district. Distributing ring, it extends around irregularly, especially northwest and southeast.

Yinhui Zhanga, Yi Luob, Wenwu Zhao*c

aCenter for Earth Observation and Digital earth,Chinese Academy of Sciences, Beijng, China 100190;

bInstitute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijng, China 100101;

cState Key Laboratory of Earth Surface Processes and Resource Ecology, College of Resources Science and Technology, Beijing Normal University, Beijing, China 100875

ABSTRACT

This study analyzed spatial and temporal changes in land use in an irrigation district covering an area of 1.7 million ha in Northern China by GIS analyses and also investigated changes in landscape pattern using the landscape structure analysis program FRAGSTATS over the study period from 1986 to 2000. The decrease in farmland and increase in grassland area mainly resulted from the policy of grain for green and converting slope farmland into pasture from China government. In spite of the efforts to conserve the fragile ecosystem, land degradation, including soil salinization and grassland degradation, was spreading rapidly. The area of alkali-saline land increased by 22493 ha and about 50555 ha of dense grassland degraded into mid-density grassland. In term of landscape fragmentation, both farmland and dense grassland showed the tendency of increased fragmentation. Both adverse natural conditions and human activities are responsible for the land degradation expansion in Hetao irrigation district, but the root causes were increasing population pressure and irrational human activities, such as flooding irrigation method and over-grazing. To prevent land degradation from spreading, population control and improvement of the management are prerequisite approaches.

XU Xingang* , Wang Jihua, Li Cunjun, Huang WenJiang, Song Xiaoyu

National Engineering Research Center for Information Technology in Agriculture, P.O. Box 2449-26, Beijing, 100097, P.R. China

ABSTRACT

Height is one of important indices during winter wheat growth. It can be not only used to indicate growth status of winter wheat, but also play a very important role in wheat growth environmental simulating models. Remote sensing images can reflect vegetation information and variation trend on different spatial scales, and using remote sensing has become a very important means of retrieving crop growth indices such as H(height), F(vegetation coverage fraction), LAI(leaf area index) and so on. In the paper, firstly LAI was estimated with a gradient-expansion algorithm by combining remote sensing images of LandsatTM with field data of winter wheat measured in Shunyi&Tongzhou District, Beijing in 2008, and then applied the dimidiate pixel model with NDVI (Normalized Difference Vegetation Index) from landsatTM to calculate F(vegetation coverage fraction), lastly taking the ratio of LAI and F as the factor built the model to estimate winter wheat growth height. The result displayed that the determinant coefficient R2 arrived at 0.48 between the field measured and the fit value by the wheat height estimating model, which showed it was feasible to apply the model with multispectral remote sensing images to estimate the wheat height.

Zhongliang Fu∗, Wenjuan Zhang

School of Remote Sensing and Information Engineering, Wuhan University, Wuhan, China, 430079

ABSTRACT

3D Visualization of Large Scale terrain data is a research hot spot in GIS, VR and simulation, etc. Most existing terrain visualization algorithms store terrain data in local disks or files, which lead to weak independence between the programs and data, and it is difficult to share data. In order to implement data sharing and distributed application for large scale terrain, a database-based optimized algorithm for terrain dataset organization, storage, scheduling and multi-resolution rendering is introduced. Firstly, the large regular grid terrain data is partitioned into many small blocks, and each block is subdivided from top to bottom to build a multi-resolution hierarchical structure based on a quad-tree, the tiles represent for simplified models of different detail level in a data block. Then, each tile is assigned a unique code and stored as a record in the pre-designed terrain database. To implement rapid data retrieval of the real time terrain walkthrough, an efficient coding method and pyramid indexing algorithm is proposed. During terrain walkthrough, the code values of necessary tiles are calculated according to the view distance and view frustum, and the corresponding tiles are quickly searched and loaded into internal memory by database index and code information. In internal memory, the famous Real-time Optimally Adapting Meshes (ROAM) algorithm is adopted to dynamically adjust the render level of different nodes in view frustum. By splitting and merging operation of binary triangle tree, the multi-resolution modes are constructed. Next, the final triangle mesh is rendered as a subset of triangle strips, which is beneficial to reduce rendering nodes and improve drawing efficient. Finally, a prototype system is developed based on C++ language and OpenGL, with the techniques of data tile coding, database indexing, incremental scheduling based on cache, triangle strip optimizing, visual smoothing and multithread programming, the efficiency and effect of the terrain visualization are greatly improved. Furthermore, the database-based algorithm can achieve large scale terrain data sharing and distributed application, which owes to the mechanism of assorting the visualization algorithms on the Client side with designating and transferring data on the Server side.

LI Xiumei, LIU Xianbin∗, LIU Lina, XUE Kun

Tianjin Key Lab of Marine Resource & Chemistry, Tianjin University of Science & Technology, Tianjin 300457, China

ABSTRACT

As remote sensing image contains abundant land surface information, it is widely used in ecological survey. However, different fields need different information, how to extract thematic information from remote sensing image seems particularly important. In this paper, several methods of extracting water-body information, such as Gray-level Thresholding Method, Spectrum-photometric Method, Band Ratio Method, Normalized Difference Water Index, were summarized and selected in order to obtain the best results. Then the methods were compared and analyzed based on TM data. Finally, the results showed that Gray-level Thresholding Method is the least ideal extraction, and Normalized Difference Water Index is the best of all. Each means has its own distinguishing feature. Combination of the different methods could achieve the best results.

LIU Miao*^ab, LIN Qi-zhong^a, WANG Qin-jun^a

In order to search for new prospect areas of iron ore resources in Isabela, Philippines, the comprehensive technologies of remote sensing and high precision magnetic method are applied, which can combine the macro-characteristics of remote sensing with the detailed detection of geophysics. Remote sensing geological characteristics, including the linear structures, the ring structures and the linear-ring structure combination are analyzed in emphasis. In addition, the high-precision magnetic measurement is carried out in the geophysical survey area. At last, by analyzing the distribution of the inferred magnetic body in the geophysical survey area and the relationship between the linear-ring structure combination and the two known iron ore occurrences, the prospecting model is established. In the study area, Northwest or northeast trending faults combined with ring structures are beneficial to the mineralization, which is verified in the known iron ore occurrences. Five target areas which have similar metallogenic conditions as known iron ore occurrences are predicted depending on the model. It is proposed that the further work should be done within 8 kilometers along the northeast side of the northwest trending piedmont regional fault and those hydrothermal deposits which correlate with intermediate intrusive rocks should be put emphasis upon.

Hu Zhiding*a, Wang Huia,

aInstisute of Surveying and Mapping, Zhen Zhou LongHai.RD, 66#, CHINA 0371;

ABSTRACT

In this paper, Begin with the base theory of the image compression and the feature extract, the characteristic of the information loss of the lossy compression and the point feature of image was analyzed. And the affect of information change of the compressed image on point feature extraction was studied. In the experiment, the JPEG, a still picture compression standard used widely, was chose as the lossy compression tool. And the point feature extraction operator was Harris Operator which has good performance. The result of the experiment suggests that the compression of the remote sensing image which with low compression ration did not affect the point feature extraction very much, when then compression ratio get high enough, the point feature extract was affected very much.

Yang Wensen^a,b

Research on ecological environment assessment of land arrangement is essential to researches on ecological environment effect. It's of great significance to practical environment protection decisions made during the layout period in order to avoid serious environment problems.

In the paper, the author has used the 3S technology and the relative knowledge of environment effect assessment. Firstly, ecological information is quantitatively extracted from remote sensing images. And then, GIS spatial analytical methods are borrowed. Finally, an ecological assessment model of land arrangement is formed on the basis of 3S technology.

As to the extraction of assessment factor, the RS technology is used to directly attain from RS image the land utilization classification chart and real-time land utilization information such as land use distribution, area and configuration. Regarding to assess factor quantification, GPS is used to check the accuracy of information extraction, and GIS is used to get the land pitch chart and the moisture distribution chart according to GIS's powerful management over data and its spatial analytical function.

The topics researched this time in the paper are as follows:

1. All-round identification of ecological environment effect factor is done. Ecological environment effect assessment index system is set up, which is a basic framework of the concrete environment effect assessment.

2. RS technology is used to pre-process remote sensing images, which includes match，correction，image enhancement etc. K-means is then followed to get land utilization distribution and information such as land areas. GPS is used to check land utilization information and GIS is borrowed to extract the assessing index information such as land pitch chart and land moisture distribution, which greatly improve the work efficiency of land arrangement ecological assessment and is of great help to make the assessment in large-scale.

3. Land arrangement environment effect assessment model is set up, in which the weight is identified through hierarchical analytical method. The ecological environment is assessed through fuzzy comprehensive assessment.

4. Every index standard value is identified, which makes the assessment reliable.

5. Based on the above methods, samples are researched, which have identified the feasibility and maneuverability of land arrangement ecological assessment based on 3S.

In all, the theory, method and index system of land arrangement environment effect assessment are deeply studied in this paper, which will offer a reference to make reasonable decisions on land assessment and land utilization.

A subject-driven open teaching model of digital earth in China

ZHOU Xu∗, LEI Jin-ong, ZHAI You-long, CHEN Ke

School of Land and Resource, China West Normal University, Nanchong, Sichuan，637002, China

ABSTRACT

According to those problems exist in the teaching practice of digital earth in GIS specialty of China West Normal University (CWNU), this paper mainly discuss a subject-driven open teaching mode of digital earth from these views of integrations of teaching contents, organizations of exploring subjects, reconstructions of teacher-student relationship, etc. Therefore, not only this model’s teaching ideas, but also its teaching contents, teaching methods and teaching environment have an obviously open characteristic.

Chen Pan*, Yi Lin, Yingying Chen

Research Center of Remote Sensing and Spatial Information Technology, Tongji University, Shanghai, China 200092

ABSTRACT

Urban land cover monitoring has been a hot spot about the global environmental change and sustainable development. Remote Sensing (RS), the core of rapid developed modern spatial information technology, has been widely used in monitoring land change and urban expansion. Chongming, the third largest island in China, the largest estuary alluvial island in the world, is located in the north of Shanghai, at the mouth of Yangtze River. In this paper, the multi-source data including high resolution RS imagery and digital topographic maps are applied to acquire the information of urban land cover in Chongming, where some related information processing methods are analyzed.

Firstly, the overall framework is proposed to apply multi-source data to extracti and classify the urban land cover. The main techniques are : integration of high resolution RS images with other information , extraction and establishment of feature library , expression and features of typical land cover classes, classification of high resolution RS images based on an effective classifier, and so on. Based on the above framework, taking the data of Chongming as a sample, some related information processing and extracting are designed and achieved.

After that, some classes of urban land cover are extracted and the high resolution RS imagery is classified based on C5.0 decision tree classifier. A classification system for urban land cover in the study area includes mainly water, road, building, cropland, vegetation, woodland, and bare ground in this paper. In the feature library of different urban land cover designed and established above, there are three features: spectral feature, texture feature, and shape information. Spectral and texture features are acquired from the RS imagery, and shape information is computed from digital vector maps using ArcGIS. Then, based on multi-feature, the classification model via C5.0 decision tree is constructed to realize the urban land cover classification, and extract the different land cover classes.

Finally, the result and precision of extraction and classification are analyzed. Usually the comparison among different classification methods can be used to assess the classification accuracy of the applied methods. In this paper the comparison is performed from two aspects. On the one hand, the high resolution RS image is classified separately using maximun likelihood classification method and minimun distance classification method based on the same training and testing samples. By comparing the accuracy of results based on different classification methods, the classification accuracy using C5.0 decision tree classifier is higher than the others. On the other hand, high resolution RS image is classified separately based on multi-source data and RS imagery only. The results of comparison show that the classification accuracy based on multi-source data is higher than the other.

From the case study in Chongming, it is proved that high resolution RS image based on multi-source data can be classified accurately and urban land cover classes can be extracted effectively using C5.0 decision tree classifier.

Chen Huilian *, Zhong Ruofei, Qin Tao

Capital Normal University Key Lab of 3D Information Acquisition and Application, MOE, Beijing China, 100048

ABSTRACT

Traditional GIS map service generally provides some simple spatial data analysis, such as the enquiry of the location, the shortest path analysis, analysis of the buffer zone, and so on .People online ask for more services with a growing demand nowadays , so these services can no longer meet the people's needs, not only the shortest path between the two places what the web is giving , they would also like to know more detail about information of this strange street, such as the special features along the street ,so that they can have a direct sense of the street. In order to fix this problem, media is used in GIS field. And in this paper, the author will focus on the design and application of Video Geographic Information System based on WebGIS,which is applied to the city's tourist areas. As it’s not easy to get the map and video synchronous, based on the technology of VideoGIS, this paper gives a solution of this problem in detail. And taking the streets of Capital Normal University for example, this paper gives an simple instance of the video-distributing system.

Xing Liu *^a, Yanmin Wang ^a, Ruiju Zhang ^a

For 3D scattered point cloud data, a new approach of extracting section line directly without construct a 3D model is proposed. First, a section plane is made as needed, then the points which on both sides of the plane are projected exactly on the section plane based on the given distance threshold. Second, a double link-list method is used to sort the refined points. Last, preliminary unsmoothed section line need feature point extraction, next outside points are connected to a line, and the center line could approximate regarded as the final section line.

YANG Xu∗, LIU De-chang, ZHANG Jielin

Beijing Research Institute of Uranium Geology, National Key Laboratory of Remote Sensing Information and Image Analysis Technology, Beijing 100029, China

ABSTRACT

Currently，contradiction between the supply and demand of uranium resources is increasing．Remote sensing technology, as one of key technoligies of “Digital Globe”, has brought into playing important action in prospecting for uranium resources. With the development of remote sensing, the resolution of spatial, spectral and temporal has being improved quickly. In addition, Tarim Basin is an important uranium mineralized region in our country. In this study, multi-source remote sensing data were used to successfully extract the information of ore-bearing bed, ore-control structure and mineralized alteration in Wuqia-Kuche area in Tarim Basin. This study undoubtedly has an important practical and theoretic meaning to advance prospecting technique level and improve ore-finding effect and efficiency．