Design and Implementation of WebGIS-based GPS Vehicle Monitoring System

This paper develops a WebGIS\|based GPS vehicle monitoring system with typical three\|tier application architecture of B/S pattern. It provides ordinary registered users with a valid and convenient means to get access to real\|time GPS location information of certain moving vehicles at any place, and further offers a powerful tool for super users to manage user information and remotely monitor those vehicles and provide corresponding services timely if necessary. The system architecture, function modules, key technologies and application interfaces are given. Finally, the validity of our system is demonstrated in practical cases.

Model for water pollution remote sensing based on double scattering and its application in the Zhujiang River outfall

It is a valid route for quantitatively remote sensing on water pollution to build a model according to the physical mechanisms of scattering and absorbing of suspended substance, pollutant, and molecules of water. Remote sensing model for water pollution based on single scattering is simple and easy to be used, but the precision is affected by turbidity of water. The characteristics of the energy composition of multiple scattering, are analyzed and it is proposed that, based on the model of single scattering, if the flux of the second scattering is considered additionally, the precision of the model will be remarkably improved and the calculation is still very simple. The factor of the second scattering is deduced to build a double scattering model, and the practical arithmetic for the calculation of the model is put forward. The result of applying this model in the water area around the Zhujiang(Pearl) River outfall shows that the precision is obviously improved. The result also shows that the seriously polluted water area is distributed in the northeast of Lingding Sea, the Victoria Bay of Hong Kong, and the Shengzhen Bay.

Research on Characteristics of Focal Rupture of the Zhangbei-Shangyi Earthquake by Means of Deformation Field Obtained by Spaceborne D-INSAR

In the last ten years, the D_InSAR (Differential Interferometric Synthetic Aperture Radar) technique has proved very useful; it has been a new space observation technique with great potential. Investigating seismic focus rupture information using D_InSAR is a scientific issue to which more attention is being paid. In this paper, the basic theory of seismic focus dislocation models is discussed briefly. Based on a map of the interferometric deformation field of the Zhangbei_Shangyi earthquake from Jan.10, 1998, and applying the seismic focus dislocation model within elastic half_space medium; some geometrical and kinematical characteristics of the main seismic fault are deduced. Results were as follows: the seismic break surface of the Zhangbei_Shangyi earthquake is left_slip and thrust fault, striking in SEE_NWW 272°with dip angle 46°; rupture direction is unilateral faulting from SEE to NWW; length of rupture zone is 9km, width is 8km, and depth is 8km, the displacement vector of three directions are 290mm, 560mm and 0mm.

Building Extraction from DSM Acquired by Airborne 3D Image

Segmentation and edge regulation are studied deeply to extract buildings from DSM data produced in this paper. Building segmentation is the first step to extract buildings, and a new segmentation method-adaptive iterative segmentation considering ratio mean square-is proposed to extract the contour of buildings effectively. A sub-image (such as 50×50 pixels )of the image is processed in sequence, the average gray level and its ratio mean square are calculated first, then threshold of the sub-image is selected by using iterative threshold segmentation. The current pixel is segmented according to the threshold, the average gray level and the ratio mean square of the sub-image. The edge points of the building are grouped according to the azimuth of neighbor points, and then the optimal azimuth of the points that belong to the same group can be calculated by using line interpolation.

Study on Dynamic Numerical Simulation of Mountain System in Tibet Plateau

Tibet Plateau in mountain system is becoming one of the focuses of global technique research, because its crust is marvelous thick, which is twice of the normal thickness of mountain system in lithosphere, and its rapid raise from the Quaternary. By using a finite element analysis software ABAQUS, the numeric analysis has been carried out and presented in this paper for the lithosphere stress field. It is the first time to use the displacement loading in the simulation of Tibet Plateau. During the analysis, the deformed elements are used to simulate the structure band, and friction mechanism is used to model the fracture band. The boundary conditions are given according to the boundary displacements around the Plateau. The stress and displacement distributions are obtained for the geological evolution of the plateau, which are consistent with P axial orientations of the seismic origin mechanism and the measures principle stress orientations. The analysis is also given for the dynamic lithosphere evolution of the Mountain System in the Tibet Plateau.

COMPUTING RESOURCE SHARING IN GROUND SYSTEM OF MULTI-SATELLITE AND MULTI-SENSOR REMOTE SENSING

A scheme is proposed to elevate the limitation of the ground application system of mono-satellite-sensor under the requirement of remote sensing satellite ground application system.In the resource-sharing, for instance caculating resource, a simple phototype of caculating-resource is proposed through analyzing resource assignment, application assignment, body structure, and so on. In order to improve the ability of assignment, realize the favorable utility, management,and maintenance, the phototype is improved by using datagrid calculation according to the requirement and character of actual application. The phototype can be taken as the foundation of calculation frame of remote sensing ground application system of multi-satellite and multi-sensor.

Spatial hazard analysis and prediction on rainfall-induced landslide using GIS

The application of landslide hazard model cou-pled with GIS provides an effective means to spatial hazard [(analysis and predic)(tion on)] rainfall-induced landslides. A modified SINMAP model is established based upon the sys-tematic investigation on previous GIS-based landslide analy-sis models. By integration the landslide deterministic model with the hydrological distribution model based on DEM, this model deeply studied the effect of underground water dis-tribution due to rainfall on the slope stability and landslide occurrence, including the effect of dynamic water pressure resulting from the down slope seepage process as well as that of static water pressure. Its applicability has been testified on the Xiaojiang watershed, the rainfall-induced landslides widespread area in Southeast China. Detailed discussion was carried out on the spatial distribution characteristics of landslide hazard and its extending trend, as well as the quantitative relationship between landslide hazard with pre-cipitation, slope angle and specific catchment area in the Xiaojiang watershed. And the precipitation threshold for landslide occurrence was estimated. These analytical results are proved useful for geohazard control and engineering decision-making in the Xiaojiang watershed.

Advances and application analysis of drought monitoring using remote sensing

在大范围、长时序的旱情监测中,遥感技术以其快速、经济和大空间范围获取的特点,弥补了基于台站气象数据旱情监测的不足,为防旱和抗旱决策提供了实时、动态、宏观的辅助决策数据。本文对已有旱情遥感监测方法进行分析和整理,将其总结为基于土壤热惯量、基于土壤波谱特征、基于蒸散模型和基于植被指数的旱情监测方法,并对各类方法从监测原理、适用范围和应用进展等方面进行了阐述。在此基础之上,详细介绍一种结合了全球植被水分指数和短波角度归一化指数的优势建立的旱情遥感监测模型和方法。以2010年春季西南地区旱情为应用案例,从监测模型方法、数据处理流程和应用分析等方面,介绍一种基于植被水分指数的旱情监测方法,并对其监测结果进行统计分析与评价。

Algorithm of emissivity spectrum and temperature separation based on TASI data

建立了适合于TASI的热红外高光谱发射率的经验关系,以此修正了分离方法(TES)中的MMD模型,在对温度和发射率进行精度评价的基础上,将反演结果应用于城市地表温度的日较差分析。结果表明:(1)反演的温度与实测温度的平均绝对误差为1.8K,平均相对误差为0.59%;(2)地面实测宽波段发射率与反演发射率的平均差值为0.036,差值的标准差为0.032;(3)同种地物的发射率曲线的反演结果与实验室测量发射率曲线的波形是一致的;(4)温度日较差分析结果是合理的。因此,本文的反演精度能满足研究需求,将该方法应用于TASI数据的温度与发射率的分离是可行的。