Abstract
Abstract. Three-dimensional (3D) remote sensing has enabled detailed mapping of terrain and vegetation heights. Consequently, forest inventory attributes are estimated more and more using point clouds and normalized surface models. In practical applications, mainly airborne laser scanning (ALS) has been used in forest resource mapping. The current status is that ALS-based forest inventories are widespread, and the popularity of ALS has also raised interest toward alternative 3D techniques, including airborne and spaceborne techniques. Point clouds can be generated using photogrammetry, radargrammetry and interferometry. Airborne stereo imagery can be used in deriving photogrammetric point clouds, as very-high-resolution synthetic aperture radar (SAR) data are used in radargrammetry and interferometry. ALS is capable of mapping both the terrain and tree heights in mixed forest conditions, which is an advantage over aerial images or SAR data. However, in many jurisdictions, a detailed ALS-based digital terrain model is already available, and that enables linking photogrammetric or SAR-derived heights to heights above the ground. In other words, in forest conditions, the height of single trees, height of the canopy and/or density of the canopy can be measured and used in estimation of forest inventory attributes. In this paper, first we review experiences of the use of digital stereo imagery and spaceborne SAR in estimation of forest inventory attributes in Finland, and we compare techniques to ALS. In addition, we aim to present new implications based on our experiences.
Highlights
The retrieval of forest inventory attributes, which are needed in forest management planning, is carried out using airborne laser scanning (ALS)-based inventory methodologies in the Nordic countries
Airborne stereo imagery can be used in deriving photogrammetric point clouds, as very-high-resolution synthetic aperture radar (SAR) data are used in radargrammetry and interferometry
First we review experiences of the use of digital stereo imagery and spaceborne SAR in estimation of forest inventory attributes in Finland, and we compare techniques to ALS
Summary
The retrieval of forest inventory attributes, which are needed in forest management planning, is carried out using airborne laser scanning (ALS)-based inventory methodologies in the Nordic countries. There is an increasing interest in the use of high-spatial-resolution digital aerial imagery (digital stereo imagery, DSI) or radar imagery to generate 3D information analogous to ALS data to support forest inventory and monitoring (Wulder et al 2013, White et al 2013, Vastaranta et al 2013, Holopainen et al 2014). This interest in alternative technologies for acquiring accurate height information can be attributed to the need to control cost and improve temporal resolution at the same time.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
