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Precise Georeferencing and Classification of 
Airborne Pushbroom Multispectral Imagery 
D. Cosandier, M.A. Chapman and P. Gong 
Department of Geomatics Engineering 
The University of Calgary 
2500 University Drive N.W. 
Calgary, Alberta 
Canada, T2N 1N4 
Tel.: (403) 220-5834; Fax: (403) 284-1890 
ABSTRACT 
Multispectral image data are finding increased application in areas such as environmental impact 
assessment, forest inventory management and change detection. A basic requirement for these and 
other applications is the need for precise georeferencing and classification. These requirements 
must be met in order for the data to play an effective role when integrated with other data types in 
geographic information systems (GIS) and decision support systems. This paper outlines a 
mathematical model which has been developed and implemented in software for the georeferencing 
of airborne pushbroom imagery. The current formulation incorporates auxiliary navigation data, 
particularly GPS and inertial navigation system (INS) data, for interpolating position and attitude 
information related to the imaging sensor exposure stations. Using the precisely georeferenced 
images, the classification of scene details is carried out using hybrid algorithms which have been 
tailored for specific applications. Results for test data sets are presented which illustrate the 
effectiveness of the georeferencing algorithm as well as the reliability of the classification 
methodology. This research was conducted under the sponsorship of a Natural Science and 
Engineering Research Council Strategic Grant. 
Proposed for ISPRS Symposium, Commission II 
Session: Real Time Mapping Technologies 
Ottawa, June 1994 
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