Geographical Data Acquisition

ISBN-13: 9783211834725 / Angielski / Miękka / 2000 / 265 str.

Y. Q. Chen; Y. C. Lee; Yong-Qi Chen

Opis

This is a book about techniques used in the acquisition of geographical data. The target audience is students and professionals using geographical information systems who want to go beyond the operation of the software and discover the general principles of how raw geographical data are acquired. By "raw" data we mean da ta acquired directly from the field, from photographs, or from maps but wh ich has not been edited or structured for database storage. With this in mind, we have placed a heavier emphasis on geo-referencing and data acquisition techniques, making the co ordinate reference framework an important link tying the chapters together. In writing thisbook, we have adopted a Scientific American-type style, which appeals to the technically curious layperson. This is more than just a collection of artides, this is a textbook written jointly by several people. The co ordination required for such an approach has made the production of this book much more difficult. The authors are predominantly faculty members of the Department of Land Surveying and Geo-Informatics at The Hong Kong Polytechnic University. We had hoped that this dose proximity of authors could help us better co ordinate the contents and ensure some consistency in style.

Spis treści

Geographical Data and Its Acquisition (Yuk-Cheung Lee): Introduction; The Nature of Geographical Data; Define the Nature and Scope of the Database; Identify the Types of Features; Design the Geographical Database; A Survey of Data Acquisition Methods; Geo-Reference Data; Trends in Spatial Data Acquisition.- Coordinate Systems and Datum (Esmond Mok, Jason Chao): Coordinate Systems; Geoid and Mean Sea Level; Datum; Ellipsoid; Geodetic and Plane Coordinate Systems.- Transformation of Coordinates between Cartesian Systems (Xiao-Li Ding): Introduction; Basic Concepts of Coordinate Transformations; Models for Coordinate Transformation; Derivation of Transformation Models; Determination of Transformation Parameters.- Map Projections (Yuk-Cheung Lee): Introduction; The Shape of the Earth; Map Projections as Mathematical Transformations; Geometric Distortions on Maps; Preserving Some of the Geometric Properties; Minimizing Geometric Distortions for a Project Area; Naming of Map Projections; Rectangular Grid System; The UTM Projection; The UTM Grid; Integrating Maps of Different Projections; Map Projection and Digital Maps; Conclusions.- Geographical Data from Analogue Maps (Yuk-Cheung Lee, Lilian Pun): Introduction; Vector and Raster Models; The Choice between Vector and Raster Models; Vector Digitizing; Raster Scanning; Conclusion.- Ground-Based Positioning Techniques (Steve Y.W. Lam, Yong-Qi Chen): Introduction; Measurement of Distances and Angles; Measurement of Height; Reduction of Coordinates to Datum; Detail Surveys.- Satellite-Based Positioning (Esmond Mok, Günther Retscher): Concept of Satellite Positioning; Absolute and Relative Positioning; Differential GPS (DGPS) Technique; Positioning Techniques for Surveying; Real-Time Kinematic Positioning; Future Developments.- Techniques for Underwater Data Acquisition (Günther Retscher): Introduction and Overview; Tidal and Other Water Level Changes; Soundings; Survey Preparation and Data Processing; Summary and Outlook onFuture Developments.- Image Acquisition (Bruce King, Kent Lam): Introduction; Image Types; Imaging Devices; Air Borne Imagery; Space Borne Imagery.- Orthoimage Generation and Measurement from Single Images (Zhilin Li): Introduction; The Principles for the Generation of Orthoimages; Measurement from Single Image; Procedure for Geo-Referencing Image and Measured Data; Summary.- Geometric Data from Images (Bruce King): Introduction; Stereoscopic Vision; Stereo Photographs; Height from Stereoscopic Parallax; Planimetric Position from a Stereopair; Analytical Methods; Digital Methodologies.- Thematic Information from Digital Images (Qiming Zhou): Factors to be Considered for Thematic Information Extraction; Feature Identification and Image Interpretation; Image Processing for Thematic Information Extraction; Summary.- Current Trends in Geographical Data Acquisition: An Epilogue (Zhilin Li, Yong-Qi Chen).- References.- Subject Index