REFERENCES 
nt /1/ Sayn-Wittgenstein, L. Large-scale aerial photography and radar altimetry. 
The state of the art. Application of remote 
sensors in forestry. Friburg, 1971. 
/2/ Nielsen, U. and Can tropical forest inventories benefit from 
Aldred, A.H. recent developments in aerial photography. 
XVI IUFRO World Congress. Oslo, 1976. 
/3/ Lyons, E.H. Forest sampling with 70-mm fixed air-base- 
photography from helicopters. Photogrammetria, 
m nr 22, 1967. 
cm 
/4/ Nielsen, U. Description and performance of the forestry 
radar altimeter. Forest Management Institute 
Information Report FMR-X-59. Ottawa, 1974. 
75/ Taits, J. Mätning i storskaliga flygbilder fôr beständs- 
datainsamling. (Photogrammetric measurements 
for stand cruising). Research Notes Nr 6, 1977. 
| Department of forest mensuration and management. 
Swedish University of Agricultural Sciences. 
Stockholm.