O'Reilly logo

Programming Microsoft® SQL Server™ 2008 by Leonard Lobel, Andrew Brust, and Stephen Forte

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Spatial Models

Let’s begin our discussion with an explanation of the two basic geospatial models: the planar and model geodetic model.

Planar (Flat-Earth) Model

The planar model is a flat surface where shapes are plotted using two-dimensional x- and y-coordinates. These coordinates are based on an arbitrary measurement system, so you can define any measurement unit you want (for example, centimeters, meters, kilometers, inches, feet, miles, pixels, and so on).

It makes sense to work with the planar model when dealing with relatively small areas (such as building floor plans), or even larger areas that are either conceptually flat or still small enough where the earth’s curvature does not skew the outcome of area and distance calculations. Realize ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required