Liu Xiu-guo

Development of Urban Geology Information System Based on MapGIS

The main objective of this study is to develop an implemented system based on MapGIS for managing and visualizing urban geology information, such as borehole, remote sensing (RS) data, geophysical and geochemical data-in Shanghai City. More than 20,000 boreholes, 80G byte RS data and other geological data were managed with three levels in the system. For the convenience of sharing information and building 3D geological model, standard forms of borehole and other geological data, such as cross-sections, were proposed. The design of urban geological datacenter is to ensure the possibility of geology information share. With B/S (browse/server) and C/S (client/server) architectures, the software architecture of the system is composed by three sub-systems: (1) The data management subsystem supported by the data center; (2) The geological data analysis and appraisal subsystem running on the intranet with C/S architecture. Most functions of the developed system were integrated in this subsystem; (3) The urban geological data share and information issue subsystem running on the internet. It is built on the basis of Web GIS and provides functions, such as information search, statistical summaries and 3D geological model browsing, which are stored in the data center for the public. As a result, the system makes the efficient management for urban geology information possible and provides a 3D virtual visualization of underground geological environment with 3D geological modeling function.

The Research of the Arbitrary Excavating Algorithm for the Stratum Structure Model

According the research of the arbitrary excavation method for the three dimensional geologic stratum model, we can be used to analyze the inner structure feature effectively in the geological work. This algorithm is based on the three dimensional geological objects represented by TIN structure. And it extracts the two key operating: “the generation of the cross section” and “the partition of geological bodies which is being cut” after the geologic stratum model being cut, and realizes the propose of purpose of the closure and segmentation. Compared with the classical [1,13] algorithm, this algorithm brings some obvious improvements. It converts the complex cutting problems to a serial of simple operations: collision detection, intersection between a line segment and a triangle, triangle mesh reconstruction, the position test between point and curve, surface or polyhedron, etc. And it expounds the excavating algorithm for the stratum model cut by the arbitrary geometric body.By cutting test with some underground geological model of Guangzhou China build with borehole data and crossing section map data, the algorithm successfully solves the problem of three dimensional geological models analysis such as arbitrary cutting, generating fence diagram, foundation ditch digging, pit excavation, tunnel digging and virtual drilling by means of three-dimensional method

HJ-1A HSI image data quality evaluation and application potential for features recognition

Using the HJ-1A HSI hyperspectral image of China and combining the methods of quality evaluation, the paper not only evaluate the data quality of radiometric precision, signal-to-noise, contrast, entropy and spectral feature fitting (SFF), but also study the ability of the features recognition, taking Wuhan region as the example. From the experiment results, we can know: 1) Its unusual from the band 1 to the band 11, and the other bands are well. 2) The ability of the features recognition is good, as the precision more than 85%. 3) The application such as agriculture, forestry, land classification, monitoring will be more effective depended on this.

Research on Land Use Supervision by Using High Resolution and Fully Polarizations Sar Data

Land is an important and fundamental natural resource which the mankind depends on for existence. Governor wants a better and cheaper mechanization to supervise land usage. The predominant source of remote intelligence for monitoring land change activities, remote sensing satellites especially Synthetic Aperture Radar (SAR)satellites are finding a niche on this arena. The high resolution and fully polarization SAR data provide a new mode for land use supervision. This paper aims to systematically analyze the SAR date representative applications in agriculture, forestry,urban planning and so on.

A new orbit fitting algorithm of space-borne SAR based on householder transformation

With the development of space-borne SAR and wide application of SAR image, the accurate positioning in geometric rectification of SAR image becomes more and more important. It corrects the image by using orbit parameters and RD location model. The orbit parameter accuracy affects the accuracy of geo-coding directly. In this paper, a new orbit fitting algorithm based on householder transformation is presented. A comparison which uses ENVISAT images as the experimental data is made between householder transformation algorithm and the traditional least squares polynomial fitting, the result shows that the new algorithm in this paper not only avoids the ill condition of traditional least squares polynomial fitting, but also have a higher positioning accuracy.