Revision as of 20:17, 13 January 2013

Introduction

This tutorial covers the basics of creating KML files. We will be using Google Earth to create KML files containing points, lines, and polygons, the three basic geometries involved in vector-based GIS.

Description of geometry types

A quick description of the basic geometry of GIS will be helpful.

There are three primary geometric types in most GIS applications.

Point

A point is a single 'spot' in space. It has no dimension, i.e. no length, width, or height. Points are typically defined by a set of coordinates, also known as a coordinate tuple. Two examples of coordinate sets include:

• (X, Y)
• (X, Y, Z)

Further reading: Wikipedia: Point

Line

A line is built of points. A sequence of points will form a line. For example:

• ((X, Y), (X, Y), (X, Y))

Further reading: Wikipedia: Line

Polygon

A polygon is similar to a line, except that its start and end points are the same. In effect, polygons are closed loops. Polygons form an area, and can have loops cut out of them.

Further reading: Wikipedia: Polygon

Install Google Earth

Skip this step if you already have Google Earth installed.

1. Visit the Google Earth website to download the installer.
2. Follow the install instructions particular to your Operating System.
3. Launch Google Earth and proceed to the next section.

Zoom to an Area

Use the Navigation Controls or your mouse to zoom in to a location. If you are unfamiliar with navigation in Google Earth, take a moment to go through the Navigation in Google Earth tutorial.

Create a Placemark

Description

Style

Altitude

Exporting KML

Single Placemarker

Grouped Placemarkers

Create a folder

Drag and Drop Placemarkers

Export Folder as KML