Remarks on Geomatics Measurement Methods Focused on Forestry Inventory

Abstract

This contribution focuses on a comparison of modern geomatics technologies for the derivation of growth parameters in forest management. The present text summarizes the results of our measurements over the last five years. As a case project, a mountain spruce forest with planned forest logging was selected. In this locality, terrestrial laser scanning (TLS) and terrestrial and drone close-range photogrammetry were experimentally used, as was the use of PLS mobile technology (personal laser scanning) and ALS (aerial laser scanning). Results from the data joining, usability, and economics of all technologies for forest management and ecology were discussed. ALS is expensive for small areas and the results were not suitable for a detailed parameter derivation. The RPAS (remotely piloted aircraft systems, known as “drones”) method of data acquisition combines the benefits of close-range and aerial photogrammetry. If the approximate height and number of the trees are known, one can approximately calculate the extracted cubage of wood mass before forest logging. The use of conventional terrestrial close-range photogrammetry and TLS proved to be inappropriate and practically unusable in our case, and also in standard forestry practice after consultation with forestry workers. On the other hand, the use of PLS is very simple and allows you to quickly define ordered parameters and further calculate, for example, the cubic volume of wood stockpiles. The results from our research into forestry show that drones can be used to estimate quantities (wood cubature) and inspect the health status of spruce forests, However, PLS seems, nowadays, to be the best solution in forest management for deriving forest parameters. Our results are mainly oriented to practice and in no way diminish the general research in this area.

Spatial Analysis of Point Clouds Obtained by SfM Photogrammetry and the TLS Method—Study in Quarry Environment

“…An uneven object with varying sizes and shapes can be accurately represented in a digital 3D model with high detail and speed. TLS applies the spatial polar method to find the spatial coordinates of points; its uses are evident in engineering and construction [21,22], industry [23,24], and land mapping [25,26]. Laser scanning and photogrammetric techniques typically use ground control points (GCP) for georeferencing [27].…”

Color-Based Point Cloud Classification Using a Novel Gaussian Mixed Modeling-Based Approach versus a Deep Neural Network

“…The latter method is easy to use, and the equipment acquisition costs are relatively low. For these reasons, it has experienced a boom over the last decade [11][12][13][14][15][16][17]. Data acquired in this way always carry (in addition to spatial information) information on point color, typically in the form of three color components (red, green, and blue, as typically captured by standard cameras).…”