1. Layering Features on a Map
TransCAD
Layering Features on a Map
2019/4/21

2. Layers and Some Examples
A layer is a group of features of the same type. Every geographic file contains at least one layer of information, and every layer has a name that describes the features within it.
Layers can be vector or raster.
2019/4/21

3. Vector & Raster
Vector layers contain map features that are points, lines, or areas which are stored in a geographic file.
Retail Stores
Cities and Towns
Highways
City Streets
Countries
ZIP or Postal Codes
Raster layers store values in rows and columns. In an image layer the values represent colors, and the set of color values is viewed as an orthophoto, a picture of a map, or another type of image.
The images are stored in files with formats such as GeoTIFF or DOQ.
Points
Lines
Areas
2019/4/21

4. Changing a Map’s Layers
2019/4/21