Section 1 Introduction

The objective of this study is to determine the influence of different structure from motion (SfM) software (e.g. Agisoft Metashap, OpenDroneMap, Pix4D) and processing parameters on processing and forest measurement outcomes. This analysis builds on Tinkham and Swayze (2021) by including UAS flights from different forests and by also comparing different SfM processing software. UAS flights from the following forests were included: the Manitou Experimental Forest on the Pike-San Isabel National Forest (Colorado; “N1”), the Black Hills Experimental Forest on the Black Hills National Forest (South Dakota; “SQ02_04”, “SQ09_02”, “WA85_02”), and the Lookout Canyon area in the Kaibab National Forest (Arizona; “Kaibab_High”, “Kaibab_Low”).