Spatial Analysis Based on Raster Data Processing - Introducing Geographic Information Systems with ArcGIS - page 483

CHAPTER 8 STEP-BY-STEP

Spatial Analysis
Based on Raster Data
Processing

Open your Fast Facts File.

Open the Color Figures file.

Exercise 8-1 (Project)

Basic Raster Principles and Operations

1. Start ArcCatalog. Make a folder named Raster_Experiments in your

___IGIS-Arc_ YourInitials

folder. Make a folder connection to that folder. Now make a File Geodatabase named Ras_Expr.
gdb inside that folder. Also make sure that the Spatial Analyst extension is turned on (You will
also have to turn it on in ArcMap later.)

First, let's create a tiny, trivial, basic raster to work with. There are several ways to create a raster. We could
create a point shapefile, as we did in the project where we mapped the computer terminals, and then convert
that to a raster. We will do that in a future project. Another method would be to use the ASCII to Raster tool
(in ArcToolbox > Conversion Tools > To Raster). This needs a text file, which we will create. (When I say “we”
will use a certain tool you have, of course, noted that I make the suggestions and you do the work.)

2. Using a text processor, make a text file as shown in the lines of characters that follow. Call the
text file Forty_Two_Cells.txt and save it in the Raster_Experiments folder.

NCOLS 7

NROWS 6

XLLCENTER 4150

YLLCENTER 1150

CELLSIZE 100