Kie- 
ed 
textural parameters can be useful for tree species recognition as 
shown here; it may, however, be possible to determine other forest 
stand parameters as well, e.g. age of trees, crown diameter, 
number of trees per unit area, etc. 
It must be stressed that this investigation was limited to one forest 
area and to photographs from one flight only. Further investigations 
with other film material from different test sites photographed under 
different conditions will be essential, before one can draw conclusions 
that are statistically well-founded. 
In an operational system for evaluating aerial photographs it would 
not be necessary to determine all the primary textural parameters 
for a large number of hardclipping thresholds as it has been done in 
this feasibility study. An operational system based on this principle 
could therefore work at a considerable processing speed. 
Acknowledgement 
The textural analysis was performed with the aid of the Quantimet 720 
of the Institut for Technical Physics at the Technical University in 
Vienna. I am grateful to Prof. H. Ebel for the permission to use 
this instrument, and to Mr. Gróger for valuable assistance in 
operating the system. 
References 
HILDEBRANDT, G.: Die Bedeutung der Fernerkundung für die 
Forstwirtschaft. Proceedings of the 36  Photogramm. 
Week at Stuttgart University, Sept. 1977, p. 187-206. 
KALENSKY, Z., and WIGHTMAN, J.M.: Automatic forest mapping 
using remotely sensed data. Remote Sensing in Forestry, 
Proceedings of the Symposium held during the XVI. 
IUFRO World Congress, Oslo, June 1976, p. 115-135. 
Date of preparation: 14. 7. 1978