COMUNICAÇÕES TEMA 4 454 P l a n n i n g a n d A c q u i s i t i o n o f C o n t r o l D a t a t o V a l i d a t e F o r e s t I n v e n t o r y a n d t h e E s t i m a t i o n o f F u e l V a r i a b l e s D e r i v e d f r o m L i D A R D a t a a n d H i g h R e s o l u t i o n C I R I m a g e s Luísa Gomes Pereira 1 , Gil Gonçalves 2,3 , Paula Soares 4 , Sílvia Cambra 2 , Sérgio Carvalho 4 e Margarida Tomé 4 1 Escola Superior de Tecnologia e Gestão de Águeda. Apartado 473, 3754-909 ÁGUEDA 2 Universidade de Coimbra. Departamento de Matemática. Apartado 3008, 3001-454 COIMBRA 3 Instituto de Engenharia de Sistemas e Computadores de Coimbra -INESCC. Paço das Escolas, 3004-531 COIMBRA 4 UTL. Instituto Superior Agronomia. Centro de Estudos Florestais. Tapada da Ajuda 1349-017 LISBOA Resumo. The estimation of forest and fuel variables by using LiDAR data and CIR high-resolution images is the main objective of the project PTDC/AGR-CFL/72380/2006 financed by the Portuguese foundation Fundação para a Ciência e Tecnologia (FCT). To estimate those variables a novel software system needs to be developed and tested. To this end, control data are necessary. In this article it is addressed the planning and acquisition of traditional forest inventory data in pure eucalyptus strata as well as topographic data. The latter is acquired with the classical topographic methods by means of a total station and by using global positioning techniques with the help of high precision GPS receivers. Key words: Forest inventory, fuel variables, LiDAR, CIR images *** Introduction One of the indispensable conditions for a sustainable development is a detailed and up-to-date knowledge of the available natural resources. In the case of Portugal, an important natural resource is that of its forests. Crucial information for foresters and land-use planners concerns, in particular, tree species, tree position, stand density, dominant height and stand volume and biomass per hectare. In relation to forest fires – which have attained dramatic proportions in Portugal in the years 2003 to 2005 – the need for additional information on vegetation variables like density and height, as well as on terrain morphology must be stressed. Such information is fundamental for predicting the risk of ignition and fire dynamics. Presently, the essence of forest mensuration is still in obtaining field information by sampling of trees inside plots and subsequent extrapolation to stands and large areas. Airborne laser scanning, by its nature, presents itself as a promising technique to obtain detailed 3D information about terrain and the mean tree crown and height, and thus volume and biomass, in a fast manner (SUÁREZ et al., 2005; NAESSET et al., 2004). Research related to airborne laser scanning for forest inventory has been active in the Nordic countries for about 15 years