Geoscience Reference
In-Depth Information
1
CHAPTER
Putting the Map Back in
Map Accuracy Assessment
Russell G. Congalton
CONTENTS
1.1 Introduction...............................................................................................................................1
1.2 Accuracy Assessment Overview ..............................................................................................2
1.2.1 Historical Review .........................................................................................................2
1.2.2 Established Techniques and Considerations ................................................................3
1.2.3 The Error Matrix ..........................................................................................................3
1.2.4 Discrete Multivariate Analysis .....................................................................................4
1.2.5 Sampling Size and Scheme ..........................................................................................4
1.2.6 Spatial Autocorrelation .................................................................................................6
1.3 Current Issues and Needs.........................................................................................................6
1.3.1 Sampling Issues ............................................................................................................6
1.3.2 Edge and Boundary Effects..........................................................................................6
1.3.3 Reference Data Collection ...........................................................................................7
1.3.4 Beyond the Error Matrix: Fuzzy Assessment ..............................................................7
1.3.5 Error Budget Analysis ..................................................................................................8
1.3.6 Change Detection Accuracy Assessment .....................................................................8
1.4 Summary...................................................................................................................................9
References ........................................................................................................................................10
1.1 INTRODUCTION
The need for assessing the accuracy of a map generated from any remotely sensed data has
become universally recognized as an integral project component. In the last few years, most projects
have required that a certain level of accuracy be achieved for the project and map to be deemed a
success. With the widespread application of geographic information systems (GIS) employing
remotely sensed data as layers, the need for such an assessment has become even more critical.
There are a number of reasons why this assessment is so important, including:
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