To make it easier for forestry planning the forest owners needs data which describe characteristics of the forest. Such data you usually get from some type of inventory. A relatively new technology which probably is getting more important in the future, is laser scanning because of lower costs. But because the laser technology is relatively new you need to compare it with conventional inventory technologies to get better understanding of the possibilities the laser technology gives. This work intends to estimate field measured characteristics of the forest from laser data with help of regression analysis and then see which of the field measured properties that best could be estimated and which laser variables that gave the best results. This study shows that heights has the best estimates, but biomass, diameter and volume also gives good estimates.

Regeringen har givit Skogsstyrelsen i uppdrag att ta fram bättre data om det svenska skogarna baserat på laserdata. Den här studien behandlar betydelsen av referensytors positionering och effekt på skattning av skogliga variabler. Riksskogstaxeringens (RT) provytor är positionerade med GPS, men under 2013 har ett antal av dessa ytor givits en förbättrad koordinat med DGPS. GPS och DGPS koordinatangivelserna har kopplats samman med motsvarande yta i laserdata från den nya nationella höjdmodellen. Med statistik från laserdata har regressionsmodeller använts för att skatta skogliga variabler genom att utnyttja RTs provytor som referensytor. Medelfelet för skattningarna beräknades på regionnivå och fördelat på höjdklasser. Differensen mellan skattningarnas medelfel, baserade på skattningar med GPS och DGPS koordinaterna, beräknades.

Booth for operational planning of harvesting and for long term planning, data is today collected manually. Intensive objective field inventories are usually too expensive. To enhance optimisation of timber flow from forest to industry Moore efficient methods for measuring tree stems of standing trees are needed. The performance of terrestrial laser scanners have improved and these could possibly be used within forestry in the future. The objective of this study was to validate how a terrestrial laser scanner could be used to measure stem diameter, and to test how the errors depend on distance from the scanner and tree species. Two plots (one pine and one spruce) were used for this study.