Academic Positions

  • now 2013

    Professor

    Faculty of Geosciences and Environmental EngineeringSouthwest Jiaotong University

  • 2014 1998

    Professor

    LIESMARSWuhan University

  • 2005 2005

    Tan Chin Tuan Visiting Scholar

    Nanyang Technological University

  • 2004 2003

    The Croucher Visiting Scholar

    The Chinese University of Hong Kong

  • 1998 1997

    Research Associate

    The Hong Kong Polytechnic University

  • 1998 1997

    Associate Professor

    LIESMARS
    Wuhan University

  • 1992 1989

    Teaching Assistant

    Southwest Jiaotong University

Education & Training

  • 1997 1995

    PostDoc

    Surveying and Mapping
    Wuhan University

  • 1995 1992

    Ph.D.

    Railway Engineering
    North Jiaotong University

  • 1989 1986

    M.Sc.

    Railway Engineering
    Southwest Jiaotong University

  • 1986 1982

    B.Sc.

    Aerial Photogrammetry
    Southwest Jiaotong University

Notable Awards Granted

  • 2015
    2nd class of National Prize for Progress in Science and Technology (4th)
    Awarded for "Construction and application national digital urban geographical spatial system framework"
  • 2014
    Excellent practitioners of Surveying and Mapping of Sichuan
    Awarded by the Sichuan Bureau of Surveying, Mapping and Geoinformation
  • 2014
    Innovative GIS practitioners in Colleges and Universities
    GIS Forum of Colleges and Universities
  • 2014
    John I. Davidson President’s Award (Third Place)
    Awarded for "A Flexible Method for Zoom Lens Calibration and Modeling Using a Planar Checkerboard", American Society of Photogrammetry and Remote Sensing
  • 2014
    1st Class of Progress Prize in Science and Technology of Surveying and Mapping (4th)
    Awarded for "Provincial Emergency Command Platform Construction and Research of Surveying and Mapping"
  • 2014
    2nd Class of Prize for Progress in Science and Technology of Sichuan (4th)
    Awarded for "Provincial Emergency Command Platform Construction and Research of Surveying and Mapping"
  • 2014
    the 2nd Prize of Natural Science for Higher School Science Outstanding Achievement (in Science and Technology)
    Awarded for "Virtual Geographic Environment Theories and Methods for Geographical Experiment Research"
  • 2013
    High-level talents in Sichuan - "Thounsands Talents Program"
    Distinguished Experts in Sichuan Province Awards (No.325), by Sichuan Provincial Party Committee Organization Department and Department of Human Resources and Social Security
  • 2013
    the 1st class of Progress Prize in Science and Technology of Surveying and Mapping (1st)
    Awarded for "The 3D Geographic Information System Platform Software and Application Demonstration"
  • 2013
    the 2nd Class of Techology Invention Prize of Hubei(1st)
    Awarded for "Key Technology of 3D geographic information System Platform"
  • Dec. 2003 Jan. 2001
    Integration of Multiple Geospatial Databases
    PI, funded by the National Natural Science Foundation of China (NSFC)
  • Feb. 2003 Mar. 2000
    3D Visualization of Geospatial Information System
    PI, funded by the 7th Youth Scholar of the Fok Ying Tung Education Foundation
  • 2001
    The Information Industry Important Technical Invention Prize
    Rank 4st, awards for the "Development and Application of the Domestic GIS software: GeoStar"
  • 2001
    2nd prize of the State Science and Technology Prizes
    Rank 8st, awards for the "Development and Application of the Domestic GIS software: GeoStar"

Group Members

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Bo Wu

Associate Professor

Homepage

Yeting Zhang

Associate Professor

Homepage

Zhiqiang Du

Associate Professor

Homepage

Yulin Ding

Research Associate

Email me

Han Hu

Postdoctral Fellow

Homepage

Introduction

Prof. Zhu has supervised more than 50 Ph.D students, more than 100 masters and 5 postdocs, among which Li Yuan has won the best youth paper on the 2008 ISPRS Congress, the Ph.D dissertation of Dr. Bo Wu has been nominated as the best 100 Ph.D in 2008 and Dr. Tarek has won the scholarship of overseas students in 2008.

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An adaptive surface filter for airborne laser scanning point clouds by means of regularization and bending energy

Hu, H., Ding, Y., Zhu, Q., Wu, B., Lin, H., Du, Z., Zhang, Y., Zhang, Y., 2014
Journal PapersISPRS Journal of Photogrammetry and Remote Sensing 92, 98-111
image
Examples of DEM, bending energy and the adaptive threshold

Abstract

The filtering of point clouds is a ubiquitous task in the processing of airborne laser scanning (ALS) data; however, such filtering processes are difficult because of the complex configuration of the terrain features. The classical filtering algorithms rely on the cautious tuning of parameters to handle various landforms. To address the challenge posed by the bundling of different terrain features into a single dataset and to surmount the sensitivity of the parameters, in this study, we propose an adaptive surface filter (ASF) for the classification of ALS point clouds. Based on the principle that the threshold should vary in accordance to the terrain smoothness, the ASF embeds bending energy, which quantitatively depicts the local terrain structure to self-adapt the filter threshold automatically. The ASF employs a step factor to control the data pyramid scheme in which the processing window sizes are reduced progressively, and the ASF gradually interpolates thin plate spline surfaces toward the ground with regularization to handle noise. Using the progressive densification strategy, regularization and self-adaption, both performance improvement and resilience to parameter tuning are achieved. When tested against the benchmark datasets provided by ISPRS, the ASF performs the best in comparison with all other filtering methods, yielding an average total error of 2.85% when optimized and 3.67% when using the same parameter set.

Reliable spatial relationship constrained feature point matching of oblique aerial images

Hu, H., Zhu, Q.>, Du, Z., Zhang, Y., Ding, Y., 2015
Journal PapersPhotogrammetric Engineering and Remote Sensing 81 (1), 49-58.

Abstract

This paper proposes a reliable feature point matching method for oblique images using various spatial relationships and geometrical information for the problems resulted by the large view point changes, the image deformations, blurring, and other factors. Three spatial constraints are incorporated to filter possible outliers, including a cyclic angular ordering constraint, a local position constraint, and a neighborhood conserving constraint. Other ancillary geometric information, which includes the initial exterior orientation parameters that are obtained from the platform parameters and a rough DEM, are used to transform the oblique images geometrically and reduce the perspective deformations. Experiment results revealed that the proposed method is superior to the standard SIFT regarding both precision and correct matches using images obtained by the SWDC-5 system.

A Hybrid Spatio-Temporal Data Indexing Method for Trajectory Databases

Ke, S., Gong, J., Li, S., Zhu, Q., Liu, X., Zhang, Y., 2014
Journal PapersSensors 14 (7), 12990-13005.

Abstract

In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type.

Real-time control of human actions using inertial sensors

Liu, H., He, F., Zhu, F., Zhu, Q., 2014
Journal Papers Science China Information Sciences 57 (7), 1-11

Abstract

Our study proposes a new local model to accurately control an avatar using six inertial sensors in real-time. Creating such a system to assist interactive control of a full-body avatar is challenging because control signals from our performance interfaces are usually inadequate to completely determine the whole body movement of human actors. We use a pre-captured motion database to construct a group of local regression models, which are used along with the control signals to synthesize whole body human movement. By synthesizing a variety of human movements based on actors’ control in real-time, this study verifies the effectiveness of the proposed system. Compared with the previous models, our proposed model can synthesize more accurate results. Our system is suitable for common use because it is much cheaper than commercial motion capture systems.

三维GIS及其在智慧城市中的应用

朱庆,2014
Journal Papers地球信息科学学报 16 (2), 151-157

Abstract

三维GIS 是当今乃至未来GIS 技术的主要标志性内容之一,它突破了空间信息在二维地图平面中单调表现 的束缚,为各行各业以及人们的日常生活提供了更有效的辅助决策支持。本文重点介绍了三维GIS 的数据模型、 数据库管理和可视化分析等关键技术及其研究进展,并以武汉市为例展示了三维GIS 对城市立体空间的整体表 达,为大城市、全市域的三维数字城市建设奠定了基础,最后探讨了在智慧城市建设与城市安全中三维GIS将发挥 日益重要的时空信息承载引擎与空间智能技术支撑作用。

Virtual Geographic Environments (VGEs): A New Generation of Geographic Analysis Tool

Lin, H., Chen, M., Lu, G., Zhu, Q., Gong, J., You, X., Wen, Y., Xu, B., Hu, M., 2013
Journal Paper Earth-Science Reviews 126, 74-84.
Structure of a complete VGE

Abstract

Abstract Virtual Geographic Environments (VGEs) are proposed as a new generation of geographic analysis tool to contribute to human understanding of the geographic world and assist in solving geographic problems at a deeper level. The development of VGEs is focused on meeting the three scientific requirements of Geographic Information Science (GIScience) — multi-dimensional visualization, dynamic phenomenon simulation, and public participation. To provide a clearer image that improves user understanding of VGEs and to contribute to future scientific development, this article reviews several aspects of VGEs. First, the evolutionary process from maps to previous GISystems and then to VGEs is illustrated, with a particular focus on the reasons VGEs were created. Then, extended from the conceptual framework and the components of a complete VGE, three use cases are identified that together encompass the current state of VGEs at different application levels: 1) a tool for geo-object-based multi-dimensional spatial analysis and multi-channel interaction, 2) a platform for geo-process-based simulation of dynamic geographic phenomena, and 3) a workspace for multi-participant-based collaborative geographic experiments. Based on the above analysis, the differences between VGEs and other similar platforms are discussed to draw their clear boundaries. Finally, a short summary of the limitations of current VGEs is given, and future directions are proposed to facilitate ongoing progress toward forming a comprehensive version of VGEs.

An integrated geospatial information service system for disaster management in China

Ding, Y., Fan, Y., Du, Z., Zhu, Q., Wang, W., Liu, S., Lin, H., 2014
Journal Paper International Journal of Digital Earth (online)
The task-oriented FSM of the IDISS

Abstract

The Chinese Government and citizens face enormous challenges of disaster management as widespread devastation, economic damages, and loss of human lives caused by increasing natural disasters. Disaster management requires a complicated iterative process that includes disaster monitoring, early detection, forecasting, loss assessment, and efficient analysis of disaster reduction. Each task typically involves the use of technologists and multiple geospatial information resources, including sensors, data sources, models, geo-tools, software packages, and computing resources. However, most existing disaster management systems operate in a typical passive data-centric mode, where resources cannot be fully utilized. This impediment is partially being addressed by the increasingly complex application requirements and the growing availability of diverse resources. In this paper, we summarize and analyze the practical problems experienced by the National Disaster Reduction Application System of China. To address the issues of data-centric, centralized, isolated solutions, we propose a novel Focusing Service Mechanism, which is capable of scheduling and allocating for optimum utilization of multiple resources, to dynamically generate collaborative and on-demand disaster information services. We also demonstrate the design and implementation of the Integrated Disaster Information Service System (IDISS). Through the service strategies of Virtualizing, Wrapping, and Integrating, disaster-related resources are constructed into services in the IDISS. These services are dynamically aggregated into focusing service chains, for diverse disaster management tasks. Actual applications illustrate that the proposed service system can significantly improve the capability of disaster management in China.

A semantics-constrained profiling approach to complex 3D city models

Xie, X., Zhu, Q., Du, Z., Xu, W., Zhang, Y., 2013
Journal Paper Computers, Environment and Urban Systems 41, 309-317

Abstract

A complex 3D city model contains detailed descriptions of both its appearance and its internal structure, including architectural components. Because of the topological complexity and the large volumes of data in such models, profiling is an effective method to present the internal structure, the distributed characteristics, and the hierarchical relationships of the model to provide intuitive visual information to the viewer and to reveal the relationships between the elements of the model and the whole. However, with commonly used boundary descriptions, it is difficult to comprehensively preserve the consistency of three-dimensional profiling using existing algorithms based on geometric constraints. This paper proposes a novel semantics-constrained profiling approach to ensure the consistency of the geometrical, topological, and semantic relationships when profiling complex 3D city models. The approach transforms the 3D model’s boundary description, defined using the CityGML standard of the Open Geospatial Consortium (OGC), into a set of unified volumetric features described as solids. This approach is characterized by (1) the use of the concepts of semantic relationships, virtual edges, and virtual surfaces; (2) the semantic analysis of 3D models and the extraction of volumetric features as basic geometric analytic units; (3) the completion of structural connectivity and space coverage for each volumetric feature, which is represented as a solid model; and (4) the use of a reliable 3D Boolean operation for efficient and accurate profiling. A typical detailed 3D museum model is used as an example to illustrate the profiling principle, and the experimental results demonstrate the correctness and effectiveness of this approach.

A flexible method for zoom lens calibration and modeling using a planar checkerboard

Wu, B., Hu, H., Zhu, Q., Zhang, Y., 2013
Journal Paper Photogrammetric engineering and remote sensing 79 (6), 555-571.

Abstract

This paper presents a flexible method for zoom lens calibration and modeling using a planar checkerboard. The method includes the following four steps. First, the principal point of the zoom-lens camera is determined by a focus-of-expansion approach. Second, the infl uences of focus changes on the principal distance are modeled by a scale parameter. Third, checkerboard images taken at varying object distances with convergent image geometry are used for camera calibration. Finally, the variations of the calibration parameters with respect to the various zoom and focus settings are modeled using polynomials. Three different types of lens are examined in this study. Experimental analyses show that high precision calibration results can be expected from the developed approach. The relative measurement accuracy (accuracy normalized with object distance) using the calibrated zoom-lens camera model ranges from 1:5 000 to 1:25 000. The developed method is of significance to facilitate the use of zoom-lens camera systems in various applications such as robotic exploration, hazard monitoring, traffic monitoring, and security surveillance.

Consistency Maintenance in Collaborative CAD Systems

LIU, H., HE, F., ZHU, F., ZHU, Q., 2013
Journal Paper Chinese Journal of Electronics 22 (1), 15-20

Abstract

The difference between real-time CSCW systems and traditional distributed systems is that the former one is supposed to provide a natural, free and fast interface for multi-user interaction. However, the typical multi-user interaction method applied in 3D CAD systems is strict consistency maintenance, such as locking mechanism and floor control, which may generate a stagnant and unnatural interface. This paper proposes a 3D semanticbased Operational transformation (OT) to support less constrained multi-user interaction and to achieve consistency in collaborative CAD editing (co-CAD) systems, and it can be used in many collaborative CAD/CAM industries.

A Multi-Level Cache Approach for Realtime Visualization of Massive 3D GIS Data

Li, X., Xu, W., Zhu, Q., Hu, J., Hu, H., Zhang, Y., 2012
Journal Paper International Journal of 3-D Information Modeling 1 (3), 37-48.

Abstract

The real-time visualization of 3D GIS at a whole city scale always faces the challenge of dynamic data loading with high-efficiency. Based on the multi-tier distributed 3D GIS framework, this paper presents a multi-level cache approach for dynamic data loading. It aims to establish in 3D GIS spatial database engine (3DGIS-SDE) the unified management mechanism of caches on three levels, including: the client memory cache (CMC) oriented to sharing application, the client file cache (CFC) organized by index, as well as the application server memory cache (ASMC) of structural consistency. With the help of the proposed optimized cache replacement policy, multi-level cache consistency maintenance as well as multithread loading model designed in the paper, the engine is able to adaptively make full use of each-level caches according to their own application properties and achieve effective coordination between them. Finally, a practical 3D GIS database based on Oracle 11g is employed for test. The experimental results prove this approach could satisfy multi-user concurrent applications of 3D visual exploration.

Mathematical morphology-based generalization of complex 3D building models incorporating semantic relationships

Zhao, J., Zhu, Q., Du, Z., Feng, T., Zhang, Y., 2012
Journal PaperISPRS Journal of Photogrammetry and Remote Sensing 68, 95-111.
The LoDs produced from experimental data (for each LoD: above, illustration with original material; below, illustration with pseudo material).

Abstract

A complex 3D building model contains a detailed description of both its appearance and internal structure with authentic architectural components. Because of its high complexity and huge data volumes, using a less detailed representation for the distant visual application of such a model is preferable. However, most mesh simplification algorithms cannot preserve manmade features of such models, and the existing 3D generalization algorithms are mainly proposed for regular-shaped buildings. More importantly, neither method can consistently express geometry, topological relations, and semantics in multiple discrete Levels of Details (LoDs). This paper presents a novel mathematical morphology-based algorithm that generalizes the complex 3D building model in a unified manner using the following steps: (1) semantic relationships between components, which reflect structural connectivity in the building at a certain LoD, are defined and extracted; (2) semantically connected components are merged and trivial geometric features of the components are eliminated simultaneously, with semantics associated with components then updated according to the merging; and (3) post-process is carried out to further reduce the redundancy of facets. The semantic relationships extracted ensure the proper generalization of topological relations and semantics of building components, and mathematical morphological operations implemented in the algorithm are capable of handling closed two-manifold components of various shapes. Experiments on both complex 3D building models in the classical Chinese style and prismatic 3D city models prove the effectiveness of the proposed method.

Geo-information processing service composition for concurrent tasks: A QoS-aware game theory approach

Li, H., Zhu, Q., Yang, X., Xu, L., 2012
Journal PaperComputers & Geosciences 47, 46-59.

Abstract

Typical characteristics of remote sensing applications are concurrent tasks, such as those found in disaster rapid response. The existing composition approach to geographical information processing service chain, searches for an optimisation solution and is what can be deemed a “selfish” way. This way leads to problems of conflict amongst concurrent tasks and decreases the performance of all service chains. In this study, a non-cooperative game-based mathematical model to analyse the competitive relationships between tasks, is proposed. A best response function is used, to assure each task maintains utility optimisation by considering composition strategies of other tasks and quantifying conflicts between tasks. Based on this, an iterative algorithm that converges to Nash equilibrium is presented, the aim being to provide good convergence and maximise the utilisation of all tasks under concurrent task conditions. Theoretical analyses and experiments showed that the newly proposed method, when compared to existing service composition methods, has better practical utility in all tasks.

An Efficient Point Cloud Management Method Based on a 3D R-Tree

Gong, J., Zhu, Q., Zhong, R., Zhang, Y., Xie, X., Gong, J., Zhu, Q., Zhong, R., 2012
Journal PaperPhotogrammetric Engineering & Remote Sensing 74 (4), 373-381

Abstract

Vehicle-borne laser-scanned point clouds have become increasingly important 3D data sources in fields such as digital city modeling and emergency response management. Aiming at reducing the technical bottlenecks of management and visualization of very large point cloud data sets, this paper proposes a new spatial organization method called 3DOR-Tree, which integrates Octree and 3D R-Tree data structures. This method utilizes Octree index rapid convergence to generate R-Tree leaf nodes, which are inserted directly into the R-Tree, thus avoiding time-consuming point-by-point insertion operations. Furthermore, this paper extends the R-Tree structure to support LOD (level of detail) models. Based on the extended structure, a practical data management method is presented. Finally, an adaptive control method for LODS of point clouds is illustrated. Typical experimental results show that our method possesses quasi-real-time index construction speed, a good storage utilization rate, and efficient visualization performance.

A triangulation-based hierarchical image matching method for wide-baseline images

Wu, B., Zhang, Y., Zhu, Q., 2011
Journal PaperPhotogrammetric Engineering and Remote Sensing 77 (7), 695-708
Results of the triangulation-based affine-adaptive cross correlation: (a) a reference image with labeled study areas, (b) left image for the study area 1, (c) right image for the study area 1, (d) left image for the study area 2, and (e) right image for the study area 2.

Abstract

This paper presents a triangulation-based hierarchical image matching method for wide-baseline images. The method includes the following three steps: (a) image orientation by incorporating the SIFT algorithm with the RANSAC approach, (b) feature matching based on the self-adaptive triangle constraint, which includes point-to-point matching and subsequent point-to-area matching, and (c) triangulation constrained dense matching based on the previous matched results. Two new constraints, the triangulation-based disparity constraint and triangulation-based gradient orientation constraint, are developed to alleviate the matching ambiguity for wide-baseline images. A triangulation based affine-adaptive cross-correlation is developed to help find correct matches even in the image regions with large perspective distortions. Experiments using Mars ground wide-baseline images and terrestrial wide-baseline images revealed that the proposed method is capable of generating reliable and dense matching results for terrain mapping and surface reconstruction from the wide-baseline images.

Integrated point and edge matching on poor textural images constrained by self-adaptive triangulations

Wu, B., Zhang, Y., Zhu, Q., 2012
Journal PaperISPRS Journal of Photogrammetry and Remote Sensing 68, 40 - 55
Comparison of with and without edge information for the adaptive triangulations

Abstract

This paper presents an innovative image matching method for reliable and dense image matching on poor textural images, which is the integrated point and edge matching based on the self-adaptive edge-constrained triangulations. Firstly, several seed points and seed edges are obtained on the stereo images, and they are used to construct a pair of initial edge-constrained triangulations on the images. Then, points and edges are matched based on the triangle constraint and other constraints. The newly matched points and edges are inserted into the triangulations and the constrained triangulations are updated dynamically along with the matching propagation. The final results will be the final edge-constrained triangulations generated from the successfully matched points and edges. Experiments using typical space-borne, airborne, and terrestrial images with poor textures revealed that the integrated point and edge matching method based on self-adaptive triangulations is able to produce dense and reliable matching results. Moreover, from the final matched points and edges, 3D points and edges preserving the physical boundaries of objects can be further derived based on photogrammetric techniques, which is ideal for further object modeling applications.

Multiple close-range image matching based on a self-adaptive triangle constraint

Zhu, Q., Zhang, Y., Wu, B., Zhang, Y., 2010
Journal PaperThe Photogrammetric Record 25 (132), 437-453

Abstract

Reliable image matching is an essential and difficult task in digital photogrammetry and computer vision. Possible problems from geometric distortions, illumination changes, scale changes and difficult texture conditions will result in matching ambiguity, especially for close-range image matching. This paper presents a multiple close-range image matching method for surface reconstruction based on a self-adaptive triangle constraint. This method features two aspects. First, the triangles constructed from the previously matched interest points provide strong geometric constraints for the subsequent point matching combined with gradient orientation and disparity constraints. The dynamic update of the triangulation adapts automatically to the changes of image textures. Secondly, a consistency check in object space is performed to remove possible mismatches. Using three sets of actual triple overlapped close-range images for the experiment, the results revealed that the proposed method provides improved matching reliability.

Knowledge-based building reconstruction from terrestrial video sequences

Tian, Y., Gerke, M., Vosselman, G., Zhu, Q., 2010
Journal PaperISPRS Journal of Photogrammetry and Remote Sensing 65 (4), 395-408
Reconstruction results from extracted line and surface features, guided by the building knowledges

Abstract

The paper presents an automatic method for the reconstruction of building models from video image sequences. These videos may be recorded using a hand-held camera or a camera mounted on a moving car. Such terrestrial video sequences are economic and flexible. Presenting buildings as geometric models–rather than for instance a representation from a simple meshing of 3D points–enables one to perform a wide range of analyses. However, sparse 3D points and 3D edges do not contain topological relations. Therefore, integrating building structure knowledge into the reconstruction steps plays an important role in our method. First, some rules are applied to reasonably group the extracted features. Then, a suitable outline and normal direction are specified for each surface patch. Based on these surface patches, a hybrid model- and data-driven method is used to recover a building model from both the extracted surface patches and hypothesized parts. Using the building structure knowledge leads to a simple and fast reconstruction method, and also enables one to obtain the main structures of buildings. The results show that this method correctly sets up topological relationships between generated surface patches and also obtains reasonable structure models in occluded areas. Therefore, the reconstructed models satisfy requirements for both visualization and analysis.

Quantitative analysis of discrete 3D geometrical detail levels based on perceptual metric

Zhu, Q., Zhao, J., Du, Z., Zhang, Y., 2010
Journal PaperComputers & Graphics 34 (1), 55-65
The comparison results of a facade (Eq represents equal interval and exp represents exponential interval)

Abstract

Aiming at the fundamental issue of optimal design of discrete levels of detail (LOD) for the visualization of complicated 3D building façades, this paper presents a new quantitative analytical method of perceptible 3D details based on perceptual metric. First, the perceptual metric is defined as the quantitative indicator of the visual perceptibility of façade details at a given viewing distance. Then, according to the human vision system, an algorithm employing 2D discrete wavelet transform and contrast sensitivity function is developed to extract the value of perceptual metric from the rendered image of the façade. Finally, a perceptual metric function is defined, based on the perceptual metric values extracted at equal interval viewing distances. The minimum detail redundancy model is then proposed for the optimal design of discrete LODs. This method provides a quantitative instruction for generating discrete LODs. The experimental results prove the effectiveness and great potential of this method.

Semantics-based 3D dynamic hierarchical house property model

Zhu, Q., Hu, M., 2010
Journal PaperInternational Journal of Geographical Information Science 24 (2), 165-188
Description of hierarchical levels of detail

Abstract

Aiming at the increasing critical issues of existing 2D plans and map‐based methodology for integrated management of advanced buildings and related dynamic property rights in complicated 3D built environments, a novel semantics‐based 3D dynamic house property model with hierarchical levels of detail is proposed in this paper, based on comprehensive analysis of 3D house property objects and various application requirements. This model is characterized by: (1) 3D geometric semantics: a 3D geometry hierarchy of exterior and interior of buildings is defined; (2) thematic semantics, comprehensive house property object and related property right relationships are illustrated; (3) temporal semantics, dynamic representation of house property driven by both geometric events and property right events is involved. This model facilitates comprehensive data mining to analyze spatial relationships and dynamic change of property rights in real 3D built environments and can also support the sale and lease of real estate, facility management, house planning and so on.

An improved segmentation approach for planar surfaces from unstructured 3D point clouds

Awwad, T.M., Zhu, Q.>, Du, Z., Zhang, Y., 2010
Journal PaperThe Photogrammetric Record 25 (129), 5-23

Abstract

The extraction of object features from massive unstructured point clouds with different local densities, especially in the presence of random noisy points, is not a trivial task even if that feature is a planar surface. Segmentation is the most important step in the feature extraction process. In practice, most segmentation approaches use geometrical information to segment the 3D point cloud. The features generally include the position of each point (X, Y and Z), locally estimated surface normals and residuals of best fitting surfaces; however, these features could be affected by noisy points and in consequence directly affect the segmentation results. Therefore, massive unstructured and noisy point clouds also lead to bad segmentation (over-segmentation, under-segmentation or no segmentation). While the RANSAC (random sample consensus) algorithm is effective in the presence of noise and outliers, it has two significant disadvantages, namely, its efficiency and the fact that the plane detected by RANSAC may not necessarily belong to the same object surface; that is, spurious surfaces may appear, especially in the case of parallel-gradual planar surfaces such as stairs. The innovative idea proposed in this paper is a modification for the RANSAC algorithm called Seq-NV-RANSAC. This algorithm checks the normal vector (NV) between the existing point clouds and the hypothesised RANSAC plane, which is created by three random points, under an intuitive threshold value. After extracting the first plane, this process is repeated sequentially (Seq) and automatically, until no planar surfaces can be extracted from the remaining points under the existing threshold value. This prevents the extraction of spurious surfaces, brings an improvement in quality to the computed attributes and increases the degree of automation of surface extraction. Thus the best fit is achieved for the real existing surfaces

A Solution to the Ambiguity Problem in Depth Contouring

Zhang, L., Liu, Y., Zhu, Q., Xiao, F., Henrik, A., 2008
Journal PaperJournal of Applied Sciences 8 (21), 3845-3853

Abstract

Depth contours on a chart are important for safe navigation. The ambiguity problem can appear when points of equal depth are joined in contouring. Unreasonable solutions may mistake a shallow area for a deep one, which could result in a potential danger for navigation. A solution is presented to solve the ambiguity problem using constrained lines formed by two shallow depths. The constrained lines are used to limit the joining of the points with equal depth. Experimental results demonstrate that the proposed solution can reduce the dangers of producing non-existent deep areas in bathymetric contouring.

An efficient algorithm to plot flooded intertidal areas

Zhang, L., Zhu, Q., Zhang, L., Liang, D., Tian, Y., 2009
Journal PaperComputers & Geosciences 35 (6), 1072-1078

Abstract

The efficient display of flooding in intertidal zones is crucial to coastal applications (e.g., coastal zone management and anti-flood directing systems). This paper proposes a new algorithm to plot flooded intertidal areas. Initially, a digital tide-coordinated shoreline (DTS) is traced on the basis of creating a digital intertidal zone model (DIZM) and an instantaneous water surface model (IWSM). Then unconnected depressions are obtained depending on the type of DTS. At the same time, the algorithm detects unconnected depressions by considering the influences of the changing water level, and creates an index from different water levels to corresponding depressions. Finally, unconnected depressions are effectively handled and flooded areas are plotted correctly. Experimental results demonstrate that the proposed algorithm results in a more accurate and efficient display than with traditional algorithms.

Hierarchical lane‐oriented 3D road‐network model

Zhu, Q., Li, Y., 2008
Journal PaperInternational Journal of Geographical Information Science 22 (5), 479-505
From 2D to 3D road networks

Abstract

The existing road‐network models based on the 2D link‐node of roadway centrelines have inhibited lane‐oriented network flow analysis and multi‐dimensional inventory management in complicated 3D urban environments. This paper proposes a hierarchical lane‐oriented 3D road‐network model (HL‐3DRNM), with a unified modelling language (UML) diagram. HL‐3DRNM is a non‐planar topological model with the support of a 3D lane ribbon cartographic display, which is characterized by: (1) multiple topological and cartographic representations and various abstraction levels (street, road segment, carriageway and lane); and (2) referenced multi‐dimensional road information (point, line, area and volume) at lane level. HL‐3DRNM provides solid mathematical foundations for a more detailed inventory management, effective network analysis and realistic navigation in the increasingly complicated 3D urban transportation systems.

A sub‐pixel location method for interest points by means of the Harris interest strength

Zhu, Q., Wu, B., Wan, N., 2007
Journal PaperThe Photogrammetric Record 22 (120), 321-335
Sub-pixel location of interest points in actual aerial image: (a) the reference image; (b) zoomed image section (4x) with interest points detected by Harris detector (grey x crosses) and their corresponding precise location (black + crosses); (c) zoomed image (15x) section, in which the white dashed lines indicate the actual edge of the road in the square.

Abstract

The sub-pixel location of interest points is one of the most important tasks in refined image-based 3D reconstruction in digital photogrammetry. The interest point detectors based on the Harris principles are generally used for stereoscopic image matching and subsequent 3D reconstruction. However, the locations of the interest points detected in this way can only be obtained to 1 pixel accuracy. The Harris detector has the following characteristics: (1) the Harris interest strength, which denotes the distinctiveness of an interest point, is a grey scale descriptor which computes the gradient at each sample point in a region around the point, and (2) the Harris interest strengths of the pixels in a template window centred on the interest point exhibit an approximately paraboloid distribution. This paper proposes a precise location method to improve the precision of the interest points on the basis of these characteristics of the Harris interest strength. Firstly, a least squares fit of a paraboloid function to the image grey scale surface using the Harris interest strength is designed in a template window and a Gaussian-distance algorithm is employed to determine the weight. Then, the precise coordinates of this interest point are obtained by calculating the extremities of the fitting surface. The location accuracy of this method is studied both from the theoretical and the practical point of view. Experimental analysis is illustrated with synthetic images as well as actual images, which yielded a location accuracy of 0·15 pixels. Furthermore, experimental results also indicate that this method has the desired anti-image-noise and efficiency characteristics.

Propagation strategies for stereo image matching based on the dynamic triangle constraint

Zhu, Q., Wu, B., Tian, Y., 2007
Journal PaperISPRS Journal of Photogrammetry and Remote Sensing 62 (4), 295-308
The propagating process of image matching.

Abstract

For the purpose of reliable stereo image matching, this paper discusses a novel propagation strategy of image matching under the dynamic triangle constraint. Firstly, the construction and the dynamic updating method for the corresponding triangulations on the stereo pairs are introduced, which are used as both constraints and carriers during the matching propagation. Then, three propagation strategies: the stochastic propagation, the adjacent propagation based on the topological relationship of triangles, and the self-adaptive propagation, which considers the texture features are proposed. The detailed algorithms of these three propagation strategies are also presented. To compare these strategies, a stereo pair with typic texture features is employed to describe the different propagation manners of these three strategies, and an experimental analysis is illustrated with different aerial stereo pairs. From test results, the following has been found: (1) stochastic propagation gives the worst matching results; (2) self-adaptive propagation performs better than the adjacent propagation by making use of the global “best first” strategy. From these conclusions, the self-adaptive propagation strategy is recommended for reliable stereo image matching under the dynamic triangle constraint.

An efficient 3D R-tree spatial index method for virtual geographic environments

Zhu, Q., Gong, J., Zhang, Y., 2007
Journal PaperISPRS Journal of Photogrammetry and Remote Sensing 62 (3), 217-224

Abstract

A three-dimensional (3D) spatial index is required for real time applications of integrated organization and management in virtual geographic environments of above ground, underground, indoor and outdoor objects. Being one of the most promising methods, the R-tree spatial index has been paid increasing attention in 3D geospatial database management. Since the existing R-tree methods are usually limited by their weakness of low efficiency, due to the critical overlap of sibling nodes and the uneven size of nodes, this paper introduces the k-means clustering method and employs the 3D overlap volume, 3D coverage volume and the minimum bounding box shape value of nodes as the integrative grouping criteria. A new spatial cluster grouping algorithm and R-tree insertion algorithm is then proposed. Experimental analysis on comparative performance of spatial indexing shows that by the new method the overlap of R-tree sibling nodes is minimized drastically and a balance in the volumes of the nodes is maintained.

A filtering strategy for interest point detecting to improve repeatability and information content

Zhu, Q., Wu, B., Wan, N., 2007
Journal PaperPhotogrammetric Engineering and Remote Sensing 73 (5), 547-553

Abstract

This paper compares several stereo image interest point detectors with respect to their repeatability and information content through experimental analysis. The Harris-Laplace detector gives better results than other detectors in areas of good texture; however, in areas of poor texture, the Harris-Laplace detector may be not the best choice. A featurerelated filtering strategy is designed for the Harris-Laplace detector (as well as the standard Harris detector) to improve the repeatability and information content for imagery with both good and poor texture: (a) the local information entropy is computed to describe the local feature of the image; and (b) the redundant interest points are filtered according to the interest strength and the local information entropy. After the filtering process, the repeatability and information content of the final interest points are improved, and the mismatching then can be reduced. This conclusion is supported by experimental analysis with actual stereo images.

An efficient depression processing algorithm for hydrologic analysis

Zhu, Q., Tian, Y., Zhao, J., 2006
Journal PaperComputers & Geosciences 32 (5), 615-623
Comparison of extraction on a plain region. (a) Extraction result of proposed method. (b) Extraction result of method implemented in ArcGIS.

Abstract

Depression filling and direction assignment over flat areas are critical issues in hydrologic analysis. This paper proposes an efficient approach for the treatment of depressions and flat areas, based on gridded digital elevation models. Being different from the traditional raster neighborhood process which is time consuming, a hybrid method of vector and raster manipulation is designed for depression filling, followed by a neighbor-grouping scan method to assign the flow direction over flat areas. The results from intensive experiments show that there is a linear relationship between time efficiency and data volume, and the extracted hydrologic structures of flat areas are also more reasonable than those proposed by the existing methods.

Seed point selection method for triangle constrained image matching propagation

Zhu, Q., Wu, B., Xu, Z.X., 2006
Journal PaperGeoscience & Remote Sensing Letters IEEE 3 (2), 207-211
Automatic selection of seed points

Abstract

In order to select proper seed points for triangle constrained image-matching propagation, this letter analyzes the affects of different numbers and different distributions of seed points on the image-matching results. The concept of distribution quality is introduced to quantify the distribution of seed points. An intensive experimental analysis is illustrated using two different stereo aerial images and, based on the experimental results, a seed point selection strategy for triangle constrained image-matching propagation is proposed. An automatic selection method is then introduced that gives good distribution quality for a defined number of seed points.

Triangulation of well-defined points as a constraint for reliable image matching

Zhu, Q., Zhao, J., Lin, H., Gong, J., 2005
Journal PaperPhotogrammetric Engineering & Remote Sensing 71 (9), 1063-1069
The matching propagation in a water area of poor texture: (a) initial matching result, (b) further matching result, (c) final matching result.

Abstract

This study demonstrates the utilization of the well-defined points to improve the reliability and accuracy of image matching. The basic principle is: (a) to triangulate a few well-defined points within the stereo model area to form a coarse triangulation; (b) to detect certain amount of corners within each triangle for further matching; (c) to propagate the matching of corner points from the reference points (i.e., the three triangle vertices) to obtain the best matching for each of these corners; (d) to dynamically update the triangulation by inserting the newly matched corner; and (e) to further detect corners and perform matching for them until a pre-defined criteria (the minimum size of triangle or the largest number of points matched) is reached. Experimental results reveal: (a) the false matching caused by the occlusion and repetitive texture is diminished; (b) the accuracy is improved, i.e., with a reduction of RMSE of check points (located in different types of terrain areas) by 12 percent to 62 percent, and a reduction of the largest error by up to two times; and (c) most building corners and boundary points of main objects could be matched directly and accurately.

CyberCity GIS (CCGIS): Integration of DEMs, Images, and 3D Models

Zhong, Z., Zhang, Y., Li, D., Huang, D., Zhu, Q., 2002
Journal PaperPhotogrammetric Engineering & Remote Sensing 68 (4), 361-368

Abstract

This paper examines the differences between CyberCity, three-dimensional (3D) geographic information systems (GIS) and CyberCity GIS (CCGIS). A CyberCity is defined as a virtual representation of a city that enables a user to explore and interact in cyberspace with the vast amount of environmental and cultural information gathered about the city. The technical characteristics of a CyberCity GIS prototype software are reported, including the 3D hierarchical modeling technique, the integrated database structure, and the interactive method of visualization of the 3D data of urban environments. The effective integrated data organization strategy for dynamical loading and progressive rendering, which enables CCGIS to support the development, design and presentation of a large CyberCity, is stressed. A pilot application for municipal planning and land information publications has been implemented. This pilot application proved that the hierarchical 3D modeling method and data model are significant to the 3D GIS; the real-time visualization of a large CyberCity needs elaborate data organization and a dynamic loading strategy.

Effects of Various Factors on the Accuracy of DEMs: An Intensive Experimental Investigation

Gong, J., Li, Z., Zhu, Q., Sui, H., Zhou, Y., 2000
Journal PaperPhotogrammetric Engineering & Remote Sensing 66(9). 1113-1118

Abstract

This paper describes a series of tests that measured the effects of 4 factors (accuracy, density of source data, characteristics of the terrain surface, and modeling approaches) on the accuracy of digital elevation models (DEMs). A large area covered by 2 1:10,000-scale maps was selected for testing. The terrain types ranged from flat to hilly to mountainous. Results and conclusions are provided.

Digital terrain modeling - principles and methodology

Li, Z., Zhu, Q., Gold, C., 2005
BookCRC Press, New York. p. 340

Abstract

Digital terrain modeling has been a research area for more than 40 years in geo-sciences and has become a rather self-contained subject. Digital Terrain Modeling: Principles and Methodology is the only authored book to provide comprehensive coverage of recent developments in the field. The topics include terrain analysis, sampling strategy, acquisition methodology, surface modeling principles, triangulation algorithms, interpolation techniques, on-line and off-line quality control in data acquisition, DTM accuracy assessment and mathematical models for DTM accuracy prediction, multi-scale representation, data management, contouring, visual analysis (or visualization), the derivation of various types of terrain parameters, and future development and applications

Virtual Geographic Environments

Lin, H., Zhu, Q., 2005
Book ChapterIn: Large-scale 3D Data Integration: Challenges and Opportunities, CRC Press, New York. p. 256

Abstract

Large-scale 3D models are the cutting edge of computer technology for understanding and planning our urban environments and infrastructures. These models have emerged from two modelling structures — systems for architecture, engineering, and construction (AEC) and geographic information systems (GIS). The problems and challenges facing today’s modelers, developed for different purposes, focus almost exclusively on data integration — the ability to use data originally developed in one modeling system in the other and vice versa. This need for data transportability is not new, as evidenced by several authors in this volume. What is new is the desire to go beyond various conversion programs into an environment where data is truly integrated, where the modeling framework is more universal, and where data standards cut across software programs and vendor-specific platforms.
This book captures the excitement of researchers, organizations, and vendors in this quest. The border between data structures used within GIS and AEC continues to diminish. As these two principal forms of modeling continue to merge, as the result of increased interest in large-scale 3D models, the need for data structures capable of supporting both types of modeling efforts, as well as new types of modeling efforts that combine the best features of both simple efforts, is manifest.

Multidimensional and dynamic vehicle emergency routing algorithm based on 3D GIS

Zhu, Q., Li, Y., TOR, Y.K., 2008
Book ChapterIn: Geospatial Information Technology for Emergency Response, Taylor & Francis, Inc, Bristol, PA, USA p. 256

Abstract

When disaster occurs, the response phase is viewed as the most critical in terms of saving lives and protecting property. Exploring the development of increased efficiency in emergency services, this volume covers technological advances that allow wider, faster, and more effective utilization of geospatial information. It discusses advances in positioning, virtual reality, and simulation models leading to improved response times in emergency situations. The book also discusses legislative attempts to promote the broader sharing and accessibility of vital information. The authors cover data collection, data production, data management, and 3D routing, as well as lesser known emerging technologies.

面向任务的遥感信息聚焦服务

李德仁, 朱庆, 朱欣焰, 眭海刚, 2010
Book 科学出版社, p. 204

摘要

书系统介绍了面向任务的遥感信息聚焦服务理论与方法,包括遥感信息共享的多维动态全局逻辑模型——遥感信息球模型,以及基于此模型的任务理解、语义搜索与动态聚合的服务

数码城市地理信息系统:虚拟城市环境中的三维城市模型初探

朱庆, 林珲, 2004
Book 武汉大学出版社, 武汉, p. 282.

序言

城市化是一个国家经济发展的重要标志。据联合国《世界城市化展望: 2003年回顾》发布的数字,2003 年世界人口已有48%居住在城市,预计在2007年将达到50%以上,历史上第一次超过农村人口。我国国家统计局最近发布的结果,2003年有40.53%的人口居住在城市,与1990年同项数据18.96%相比,可以看出我国城市化的进程是逐步加快的,发展迅猛。这一方面反映了我国经济的快速增长,另一方面也对我国城市建设及相关的配套设施与政策法规提出了严峻的挑战。面对如此紧迫的形势,加快城市建设信息化的步伐将是解决城市化过程中所出现的各种新老问题的有效办法。
  城市信息化的通俗解释就是建设“数字城市”。它是要构建一个以城市地理空间(Geospace)数据和专题数据为基础,以网络计算和通信为工具,协助“人”来更有效地认识、规划、建设和管理城市,也为“人”的生存、工作、生活和安全提供保障的科技、人文环境。
  朱庆、林珲二位教授的《数码城市地理信息系统》一书的出版正是应对城市信息化建设的新形势,解决“数字城市”建设中的理论与技术问题,并预见城市信息化前景的一本非常及时的专著。作者在城市地理信息系统的概念、原理和方法上设置了一个十分确切的解释空间,搭建了一个建立数字城市地理信息系统的认知框架,并将多年来国内外同行们在这一领域所取得的丰硕成果经过分析、评价之后融入其中。为我们提供了一条能直接而便捷地进入领域核心地带的途径。
  这本书还反映了作者及其团队多年来的科研成果和经验,特别是在数字城市理论方法的深化过程中提出的空间建模、多维分析、数据质量控制等方面的见解,都有很强的启发性和指导意义。
  “数字城市”既是目标,也是一个过程。最终要达到什么样的境界目前还说不太清楚。但是可以肯定的说它不是一个单纯的技术系统,而是一个“以人为本”,人机结合的大型综合集成体系。本书在这个问题上的描述有明显的特色和亮点,尽管国内外的研究探索只是刚刚起步,但方向是清晰的,应该引起我们的重视。例如,书中提出的构建分布式的虚拟地理环境,开始强调人与虚拟环境的交互与关系;讨论了地理协同( Geocollaboration)理论在分布式虚拟地理环境中的应用,这必然会引出认知主体和客体,虚拟与实在( Reality)等跨计算机、心理学和哲学的多种问题,并将引导“数字城市”研究与开发的深化。
  在全球化的网格(Grid)技术的新环境中,城市信息化建设将有新的思路和新的举措。本书可以为这一即将到来的新变革打下一个稳固的基础。感谢作者多年的工作及在地理信息科学的学术交流方面所做的努力和贡献。

前言

城市在这个星球上的出现已经有了五千多年的历史。然而,大规模城市化是过去一百多年中发生的事情。城市的发展是与创新分不开的,这里不仅是指科技方面的创新,也包括文化方面的创新。例如,云南丽江古城凭借文化创新也迎来了发展的机会。近二十年来,城市信息化似乎成为许多中国城市发展的创新契机,并被冠以“数字城市”建设的美喻。与此同时,我们也应该看到城市本身的发展对于城市信息化也提出了挑战。譬如,珠江三角洲和长江三角洲城市群的协调发展,也呼唤出“城市群地理信息系统”的新思路。
  近年来,受到“数字地球”(digital earth)概念的影响,“数字城市”(digital city)在不同的认识层次和学科领域得到了不同的理解,因而具有两层明显不同的含义:广义上被用于描述城市信息化的目标,而狭义上则主要指城市空间信息基础设施。不管如何理解,城市地理信息系统都是其重要的核心内容,并正在积极向动态、多维和网络化方向发展。为了突出虚拟现实技术在城市空间信息交流方面的重要意义,“虚拟城市”(virtual city)也被用于描述通常由三维场景组成的城市地区,用户能够在里面移动和交互。
  城市逼真的三维数字表示由于其在城市基础设施管理、无线通讯网络规划、城市开发决策支持、污染分布仿真、土木工程与军事行动支持等众多领域显现出巨大的应用潜力,从而成为普遍关注的热点问题。如何从二维地理信息系统向城市环境三维描述(三维地理信息系统)转变正日益成为城市数据管理的时髦问题。城市的三维逼真描述——三维城市模型不仅具有传统虚拟现实表现的高度真实感,而且具有三维GIS数据库管理与分析应用等特殊功能并能与其他社会经济信息互联。因此,三维城市模型常被作为CyberCity的代名词,有关其数据获取与管理的研究受到了广泛重视。格林(Gruen)等学者将三维城市模型数据库系统称为“CyberCity Spatial Information System”(CyberCity空间信息系统)。针对城市地理环境应用,笔者认为CyberCity Geographic Information System(CyberCity GIS)的提法更为恰当,并将其翻译为数码城市地理信息系统。我们认为,数码城市地理信息系统是“数字城市”空间数据基础设施的重要组成部分,也是“虚拟城市”的核心内容;同时,也将其作为GIS向“虚拟地理环境”(virtual geographic environment)方向发展的一个初步原型。因此,本书以“数码城市地理信息系统——虚拟城市环境之三维城市模型初探”作为书名。
  尽管有关三维城市模型的研究与实践在国内外已经十分广泛,但大多数成果由于立足于特定的有限领域而且都还是分散的、不全面的。比如,广泛应用于城市规划设计评价和旅游目的的各种“虚拟城市”往往侧重于其逼真的视觉表现,而忽略了可靠的空间数据获取方法和灵活的海量数据管理与分析能力。本书力图比较全面地论述当今国内外关于数码城市地理信息系统最先进的理念和研究进展,从摄影测量与遥感和地理信息工程的角度着重论述三维城市模型的数据内容与数据快速获取方法,多种类型数据的一体化管理与集成应用,海量数据的动态交互式可视化等关键技术,为我国正在开展的城市数字化工程建设提供必要的理论铺垫和技术支持。相比其他领域,城市问题具有特别的复杂性,其对 GIS技术提出了更高的要求。因此,本书关于数码城市地理信息系统的理论方法和关键技术对数字化国土、数字化战场环境和地下工程等其他相关领域的应用实践也具有一定的适用性。同时,本书集中反应了数码城市地理信息系统平台软件CCGIS4.0(2003年度国产GIS软件测评推荐软件)研发和大量工程应用实践的成果,争取在理论研究及技术应用两方面均获得发展和创新,体现先进性、系统性、实用性和可操作性的时代要求。当然,由于研究工作的局限,有关虚拟城市环境的其他问题如时态、城市人文环境等还有待在今后的版本中予以充实。书中的许多观点也期待进一步更加广泛的争论。
  本书的完成还得到了许多人直接或间接的无私贡献。有关数码城市地理信息系统的研究与实践一直得到了武汉大学李德仁院士和龚建雅教授的关心与支持。李德仁院士在百忙中审阅了书稿,提出了宝贵的建议并给予了鼓励。解放军信息工程大学高俊院士不顾繁忙的学术活动亲自审阅全书并欣然作序,使本书增色许多,令作者深受鼓舞。要感谢测绘遥感信息工程国家重点实验室(武汉大学)和地球信息科学联合实验室(香港中文大学)有关的教师、博士研究生和硕士研究生们给予的极大支持。在几年前首次策划本书内容时,香港理工大学的李志林教授提出了许多宝贵的意见和建议,它们已经体现在今天的书稿当中。作者要感谢眭海刚博士,吴波、赵杰、黄铎、张霞、胡海棠、王静文、韩李涛、李逢春、龚俊、张叶廷、钟正等博士研究生,高玉荣和周艳等硕士研究生的辛勤付出。同时,作者还要感谢香港裘搓基金会赞助朱庆在香港中文大学地球信息科学联合实验室的访问和学术交流,使其有机会与龚建华研究员、辛晓红博士、沈大勇博士、孔云峰博士、杨育彬博士、李响、赵一斌、施晶晶和王纲胜等博士研究生进行深入讨论,并有颇多收益。本书得到了国家973项目“虚拟现实的基础理论、算法及其实现”(2002CB312101)、 国家863项目“ 虚拟地理环境的研究与开发 ”( 2001AA135130)和国家自然科学基金项目“多种类型大型空间数据库集成方法”(40001017)的资助。
  最后,作者要感谢武汉大学出版社责任编辑任翔先生以及参与本书出版编辑工作的所有老师艰苦细致的审编工作,使该书顺利面世。
朱庆、 林珲
2004年2月20日
     香港中文大学 未圆湖畔

数字高程模型(第二版)

李志林, 朱庆, 2003
Book 武汉大学出版社, 武汉,p. 296

序言

数字化是在本世纪 50年代电子计算机出现后才提出的新概念,而数字高程模型(DEM)的概念在1958年就已经提出了。到了今天,数字高程模型作为地球表面地形的数字描述和模拟已成为空间数据基础设施和“数字地球”的重要组成部分。几十年来对数字高程模型的研究始终方兴未艾、十分活跃。从1972年起国际摄影测量与遥感学会(ISPRS)一直把 DEM作为主题、组织工作组进行国际性合作研究。
  尽管有关DEM的论著和论文非常之多,但是,当我读到由李志林和朱庆写的这本书时,我仍然激动不已,一口气把它读完。我为这本书中的理论创造性、方法的实用性和对数字化生产的指导性而兴奋,中国的地球空间信息学后继有人!
  本书用简洁的语言,有条理地、系统而全面地论述了数字高程模型的概念、数据获取、建模方法、精度分析模型等。书中对由格网数据建立DEM的表面精度所作的深入分析和对DEM精度与格网间隔及等高距关系的分析具有理论创造性,是本书的一闪光点。
  为了推动DEM数据库的建立,作者集中力量对数字高程模型生产的质量控制、数据组织和高程内插方法进行了深入分析,并介绍了生产中的项目设计和数据库建库方法,这些叙述是基于作者在“九五”国家测绘局重点科技攻关项目中的实际工作和调查研究得到的结果,具有实际推广应用价值。
  对于DEM的应用,本书侧重介绍了数字地形分析、可视化和在土木工程、水利工程、环境工程及GIS中的应用。这些论述对推动DEM在各领域的应用,乃至在“数字地球”中的应用有实际意义。
  可喜的是本书的主要研究成果已在吉奥之星(GeoStar)GIS软件中得以实现,相应的软件模块GeoTIN和GeoGrid已在我国“七大江河”1:10000DEM和全国1:50000DEM数据库建立中立下功劳,成为1999年国家科技部的推荐软件。
  基于以上的理由,我愿向广大读者,包括科研、教学、生产和管理方面的读者推荐这本书。长江后浪推前浪,江山代有人才出!也希望本书的作者们不断努力,创造更大的辉煌!

前言

数字地形模拟是针对地形地貌的一种数字建模过程,这种建模的结果通常就是一个数字高程模型(DEM)。自从五十年代后期开始被用于公路设计以来,DEM受到了极大的关注,并在测绘土木工程、地质、矿山工程、景观建筑、道路设计、防洪、农业、规划、军事工程、飞行器与战场仿真等领域得到了广泛应用。
  随着科学技术特别是计算技术和空间技术的迅速发展,在DEM的数据获取方法、数据存储和数据处理速度等方面已经取得突破性进展,数字地形模拟已经成为地球科学重要的分支之一。实际上,由于地理信息系统(GIS)的普及,DEM作为数字地形模拟的重要成果已经成为国家空间数据基础设施(NSDI)的基本内容之一,并被纳入数字化空间数据框架(DGDF)进行规模化生产。今天,数字高程模型DEMs已经成为独立的标准的基础产品,并越来越广泛地被用来代替传统地形图中等高线对地形的描述。显然,跟过去提供等高线地形图一样,提供DEMs也已成为各勘测部门的基本任务和日常工作之一。全国范围内的DEMs等价于中小比例尺的基本地形图,而其他大比例尺、高精度的DEMs则与更大比例尺的地形图相当。这些高精度DEMs无疑将由更多的地方或专业部门提供。随着各种精度级别DEMs的普遍可得,过去许多潜在的应用领域现在已经变成十分重要的用户。DEMs作为地球空间框架数据的基本内容,是各种地理信息的载体,在国家空间数据基础设施的建设和数字地球战略的实施进程中都具有十分重要的作用。为了推动DEMs的生产和应用,有必要推出一本内容翔实涉及面广的著作。换句话说,经过40來年的发展,DEMs的理论基础和涉及的主要技术方法都已经成熟,这些理论与技术应该被归纳总结到这样的书中,这也是作者们致力于该项工程的主要原因。
  综合作者们十多年来在该领域的研究开发成果、汇集国内外最新的理论与技术成就,我们推出了这本著作。本书首次系统全面地论述了DEMs的概念、数据源、数据获取、建模方法、精度模型、质量控制、数字分析、可视化与应用等基本理论与关键技术,并介绍了实用的生产项目设计和数据库建设的方法。其中,绝大部分内容都是经过作者实际工作考察和对比分析后取得的成果,具有较强的针对性和应用参考价值,许多先进的技术方法都已体现在吉奥之星(GeoStar)地理信息系统系列软件中,并在生产实践中得到了广泛采用。本书力求能为与地学相关学科的各类专业技术(管理)人员进行科学研究、教学、生产和管理等工作提供较完整实用的理论依据与技术参考。
  本书是在中国科学院和中国工程院院士、测绘遥感信息工程国家重点实验室主任李德仁教授的热情鼓励和指导下完成的。承蒙他在百忙中审阅全书并作序,特此表示深深的敬意和感谢。感谢测绘遥感信息工程国家重点实验室常务副主任、首批“长江学者奖励计划”特聘教授龚健雅博士审阅全书并提出宝贵意见。 感谢研究生周艳、高玉荣和王丽圆同学在资料整理过程中付出的大量艰辛劳动。 我们也非常感谢武汉大学出版社把本书作为她的“数字地球丛书”之一跟读者见面。

Currrent Teaching

  • Present 2015

    Modeling and Analysis of Digital Surface Model

    graduate student, 36 courses, Southwest Jiaotong University

  • Present 2013

    Foundations of 3D GIS

    graduate student,Southwest Jiaotong University

Teaching History

  • 2011 2006

    Principals of Digital Surface Model

    graduate student, 36 courses, Wuhan University

  • 2006 2006

    Analysis of Digital Surface Model

    graduate student, 36 courses, Wuhan University

  • 2004 2004

    Digital Terrain Modeling: Principles and Methodology

    graduate student, 36 courses, Wuhan University

  • 2004 2003

    Advances in GIS: 3D GIS

    graduate student, 36 courses, Wuhan University

  • 2004 2000

    Digital Terrain Modeling and Digital Cities

    Ph.D. student, 36 courses, Wuhan University

  • 1996 1995

    Principals of Photogrammetry

    overseas student,Southwest Jiaotong University

  • 1991 1990

    Mapping Engineering of Railways

    Southwest Jiaotong University

At Chengdu

My office in Southwest Jiaotong University is at the top floor of the 4th Block in the Xipu campus.

I am at my office every day from 8:00 until 16:00 pm, but you may consider a call to fix an appointment.

At Wuhan

Some of my supervised students are still in LIESMARS of Wuhan University.

You can also meet me there occasionally!