John T. Sample - Böcker

The use of geospatial technologies has become ubiquitous since the leading Internet vendors delivered a number of popular map websites. Today, businesses are either migrating location-specific capabilities into their information systems, or expanding existing Geospatial Information Systems (GIS) implementation into enterprise-wide solutions. As enterprise information systems evolve toward service-oriented architecture (SOA), geospatial technologies also evolve along the same lines.Geospatial Services and Applications for the Internet covers a wide spectrum of techniques, algorithms and modeling methodologies that address the challenges in service-oriented architectural design for GIS, and intelligent processing for spatial queries. This book presents in-depth studies on performance improvement, data integration, service personalization and interoperation between geospatial services. These studies provide the reader with a wide spectrum of examples and case studies on the development of GIS for hydrological applications, electrical power supply applications, land usage and urban planning, and NASA’s Earth image datasets dissemination.Geospatial Services and Applications for the Internet is designed for a professional audience composed of practitioners and researchers in industry.  This book is also suitable as a secondary text book or reference for advanced-level students in computer science and geosciences.

The use of geospatial technologies has become ubiquitous since the leading Internet vendors delivered a number of popular map websites. Today, businesses are either migrating location-specific capabilities into their information systems, or expanding existing Geospatial Information Systems (GIS) implementation into enterprise-wide solutions. As enterprise information systems evolve toward service-oriented architecture (SOA), geospatial technologies also evolve along the same lines.Geospatial Services and Applications for the Internet covers a wide spectrum of techniques, algorithms and modeling methodologies that address the challenges in service-oriented architectural design for GIS, and intelligent processing for spatial queries. This book presents in-depth studies on performance improvement, data integration, service personalization and interoperation between geospatial services. These studies provide the reader with a wide spectrum of examples and case studies on the development of GIS for hydrological applications, electrical power supply applications, land usage and urban planning, and NASA’s Earth image datasets dissemination.Geospatial Services and Applications for the Internet is designed for a professional audience composed of practitioners and researchers in industry.  This book is also suitable as a secondary text book or reference for advanced-level students in computer science and geosciences.

Tile-based mapping systems have grown to become the dominant form of mapping system with the rise of Web-based mapping tools. The origin of this book is a desire to collect all our discoveries, techniques, and best practices for creating a til- mapping system into one combined volume. The intent of this text is to provide a comprehensive guide to the theory behind creating a tiled-map system as well as a practical guide to create a concrete implementation. Stennis Space Center, MS John Sample May 2010 Elias Ioup vii Acknowledgements The authors would like to thank the Naval Research Laboratory’s Base Program, program element number 0602435N, for sponsoring this research. Additionally, the following people provided technical assistance without which this book would not have been possible: Perry Beason, Frank McCreedy, Norm Schoenhardt, Brett Hode, Bruce Lin, Annie Holladay, Juliette Ioup, and Hillary Mesick. ix Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 1 Background of Web-Based Mapping Applications . . . . . . . . . . . . . . . 1 1. 2 Properties of tile-based mapping systems . . . . . . . . . . . . . . . . . . . . . . . 2 1. 3 Book Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Logical Tile Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. 2 Global Logical Tile Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. 3 Blue Marble Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 4 Mercator-Based Schema . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 5 Variable Start Tile Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. 6 Standardized Schema . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 Tiled Mapping Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3. 1 Tile Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3. 1. 1 Discrete Map Scales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3. 1. 2 Continuous Map Scales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3. 2 Tile Retrieval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3. 2. 1 Local Tile Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .