APPLICABILITY OF AIRBORNE PROFILING RADAR TO FOREST INVENTORY

In this work the applicability of airborne profiling radar to forest i nventory was studied in detail. The radar stand profiles were collecte d by using a helicopter-borne ranging scatterometer, HUTSCAT (Helsinki University of Technology SCATterometer), which can probe the forest c anopy from the top to the bottom due to its ranging capability. Severa l radar variables were analyzed from stand profiles, and compared with field-measured characteristics of 20 m by 20 m sample plots, by apply ing multivariate data analysis methods. It was shown that mean and dom inant height, height of the crown base line, and stem volume per hecta re can be obtained with good accuracy. Furthermore, the ranging radar can measure mean and dominant tree heights more accurately than is usu ally obtained with conventional field measurements. As possible direct application, it is proposed that radar measurements would be employed with helicopter-borne ocular inventories in order to improve the esti mation accuracy and to speed up the measurements.