Lab 6: Advanced classification and accuracy assessment

Introduction

In this lab you will learn how conduct supervised classification of satellite imagery.  You will learn several different methods of creating and evaluating signatures as well as how to measure the accuracy of your classification.  

Instructions

Read pages 203-245 of the Erdas Field Guide. Open the lab book and skim Chapter 17. You can download the tutorial file (lab6.zip) here. You will need to unzip it.  Complete the supervised classification part of the tutorial exercise (455-483) and produce a map composition of the classified map. Put your name on the map with a text box. Then do an accuracy assessment (pp 496-500) and print the results.  Answer the following questions.

1. Explain each of the different ways you defined signatures.
2. What is a feature space image?
3. What do you look for when viewing the histograms of signatures?
4. What is separability?
5. What do the univariate signature editor statistics tell you?
6. What does the covariance matrix tell you?
7. Explain the decision rules that you used to produce the supervised classification. 
8. Explain the accuracy assessment report.  Make sure you explain what the different numbers of the error matrix and overall accuracy values mean.