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GEOMETRIC AND RADIOMETRIC PREPROCESSING OF AIRBORNE VISIBLE/ 
INFRARED IMAGING SPECTROMETER (AVIRIS) DATA IN RUGGED TERRAIN 
FOR QUANTITATIVE DATA ANALYSIS 
PETER MEYER 1 , ROBERT O. GREEN 2 , KARL STAENZ 3 , KLAUS I. ITTEN 1 
demote Sensing Laboratories, Department of Geography 
University of Zurich-Irchel, Winterthurerstr. 190, CH-8057 Zurich, Switzerland 
Phone:+41 1 257’51’62/FAX:+41 1 362’52’27; Email: pmeyer@rsl.geogr.unizh.ch 
2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA 
3 Canada Centre for Remote Sensing Ottawa, Canada 
ABSTRACT: A geocoding procedure for remotely sensed data of airborne systems in rugged terrain is affected 
by several factors: buffeting of the aircraft by turbulence, variations in ground speed, changes in altitude, attitude 
variations, and surface topography. The current investigation was carried with an Airborne Visible/Infrared Imag 
ing Spectrometer (AVIRIS) scene of Central Switzerland (Rigi) from NASA’s Multi Aircraft Campaign (MAC) in 
Europe (1991). The parametric approach reconstructs for every pixel the observation geometry based on the flight 
line, aircraft attitude, and surface topography. To utilize the data for analysis of materials on the surface the 
AVIRIS data are corrected to apparent reflectance using algorithms based on MODTRAN. 
KEY WORDS: Rugged terrain, parametric rectification, atmospheric correction, MODTRAN. 
1 - INTRODUCTION 
For a comparison of remotely sensed data over large regions with conventional maps or the integration into Geo 
graphic Information Systems (GIS) for verification purposes, or for further treatment, a coregistration has to be 
performed. Also for the correction in rugged terrain of atmospheric effects and/or slope and aspect effects in a 
radiometric sense, the knowledge of the exact location of a pixel is required (Itten and Meyer, 1993). 
2 - PARAMETRIC RECTIFICATION 
2.1. Geometry Related Problems 
There are three dominating factors which affect the geometry: the geometric characteristics of the sensor, the sta 
bility of the platform and the topography. For aircraft instabilities, the flight line (x,y,z) and the attitude (roll, 
pitch, true heading) will cause shear, splay, compression and expansion of the image. Topography influences the 
geometric quality by shifting the recorded pixel location compared with the true position, and by affecting the 
pixel size (Figure 1). 
Figure -1: Influence of the topography on the pixel location (left) and pixel size (right). 
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