SOME SAMPLING ASPECTS OF GLOBAL FOREST ASSESSMENTS 
Christoph Klein 
Universitat Freiburg 
Abjeilung Forstliche Biometrie 
Werderring 6 
D-79117 - Freiburg, Germany 
ISPRS Commission VII / Working Group 10 
ABSTRACT 
Monitoring of the global development of forest area is an important and frequently discussed issue. For 
the generation of numbers on global forest area a combination of remote sensing and sampling techniques 
is favourable. This contribution discusses some technical problems when using readly interpreted satellite 
imagery of two different spatial resolutions, coarse resolution satellite data to obtain fast and frequent 
global coverages and high resolution to get more detailed informaron on forest areas (like forest types, 
spatial structure of forests): 
1. The problem of misregistration when trying to coregister sample areas in both data sources, 
2. The problem of classification rules and how compatible the classification of the two data sources area 
and 
3. The problem of determining an adequate sampling design, sample size and an adequate size of the 
sample unit. 
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