Apress Pro Spatial with SQL Server 2012 (2012).pdf

For your convenience Apress has placed some of the front

matter material after the index. Please use the Bookmarks

and Contents at a Glance links to access them.

Contents at a Glance

Contents.................................................................................................................. vii

Foreword ............................................................................................................... xxi

About the Author .................................................................................................. xxii

About the Technical Reviewer ............................................................................. xxiii

Acknowledgments ............................................................................................... xxiv

Introduction .......................................................................................................... xxv

■

Chapter 1: Spatial Reference Systems................................................................. 1

■

Chapter 2: Spatial Features ............................................................................... 21

■

Chapter 3: Spatial Datatypes ............................................................................. 51

■ Chapter 4: Creating Spatial Data........................................................................ 77

■

Chapter 5: Importing Spatial Data ................................................................... 101

■

Chapter 6: Geocoding....................................................................................... 139

■

Chapter 7: Precision, Validity, and Errors........................................................ 163

■ Chapter 8: Transformation and Reprojection................................................... 187

■

Chapter 9: Examining Spatial Properties ......................................................... 211

■

Chapter 10: Modification and Simplification ................................................... 253

■

Chapter 11: Aggregation and Combination ...................................................... 273

■ Chapter 12: Testing Spatial Relationships ....................................................... 293

■

Chapter 13: Clustering and Distribution Analysis ............................................ 327

■ Chapter 14: Route Finding ............................................................................... 353

■

Chapter 15: Triangulation and Tesselation ...................................................... 387

■ Chapter 16: Visualization and User Interface .................................................. 419

■

Chapter 17: Reporting Services ....................................................................... 445

■ Chapter 18: Indexing........................................................................................ 471

■

Appendix .......................................................................................................... 499

Index..................................................................................................................... 519

C H A P T E R 1

■ ■ ■

Spatial Reference Systems

Spatial data analysis is a complex subject area, taking elements from a range of academic disciplines,

including geophysics, mathematics, astr onomy, and car togr aphy. Although you do not need to

understand these subjects in great depth to take advantage of the spatial features of SQL Server 2012,

it is important to have a basic understanding of the theory involved so that you use spatial data

appropriately and effectively in your applications.

This chapter describes spatial reference systems—ways of describing positions in space—and

shows how these systems can be used to define features on the earth's surface. The theoretical concepts

discussed in this chapter are fundamental to the creation of consistent, accurate spatial data, and are

used throughout the practical applications discussed in later chapters of this book.

What Is a Spatial Reference System?

The purpose of a spatial reference system (sometimes called a coordinate reference system) is to

identify and unambiguously describe any point in space. You are probably familiar with the terms

latitude and longitude , and have seen them used to describe positions on the earth. If this is the case,

you may be thinking that these represent a spatial reference system, and that a pair of latitude and

longitude coordinates uniquely identifies every point on the earth's surface, but, unfortunately, it's

not quite that simple.

What many people don't realize is that any particular point on the ground does not have a unique

latitude or longitude associated with it. There are, in fact, many systems of latitude and longitude, and

the coor dinates of a given point on the ear th will differ depending on which system was used.

Furthermore, latitude and longitude coordinates are not the only way to define locations: many spatial

reference systems describe the position of an object without using latitude and longitude at all. For

example, consider the following three sets of coordinates:

•

51.179024688899524, –1.82747483253479

•

SU 1215642213

581957, 5670386

These coordinates look very different, yet they all describe exactly the same point on the earth's

surface, located in Stonehenge, in Wiltshire, United Kingdom. The coordinates differ because they all

relate to different spatial reference systems: the first set is latitude and longitude coordinates from the

WGS84 reference system, the second is a grid reference from the National Grid of Great Britain, and

the third is a set of easting/northing coordinates from UTM Zone 30U.

Defining a spatial reference system involves not only specifying the type of coordinates used, but

also stating where those coordinates are measured from, in what units, and the shape of the earth over

which those coordinates extend.

•

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: