Simultaneous Localization and Mapping (SLAM) is a framework to estimate sensor position and point clouds simultaneously in unknown environments. In surveying and construction works, the SLAM is mainly applied to dense point cloud acquisition using various mobile platforms such as backpack scanners, handheld scanners, vehicles, and UAVs. This article describes the overview of the SLAM.

We propose a method for estimating hydraulic conductivity using texture and color information from boring core images. As texture information, 14 features are computed from a density co-occurrence matrix that is invariant with respect to image translation, scaling, and rotation in π/4 radian incremants. Hue, saturation, and value are used as color information. Multiple regression analysis is performed hydraulic conductivity as the objective variable and texture and color information as explanatory variables. To verify the effectiveness of the proposed method, we conducted an experiment using boring core collected at the site of Mie Elementary Schoool in Shimabara City, Nagasaki Prefecture, Japan.

Since solar panels mounted on building facades are expected to come into wide use in urban areas, accurate estimation of photovoltaic potential of building facades is necessary for urban energy management planning. Accordingly, we have planned to develop a system to estimate photovoltaic potential of building surfaces using a 3D city model. The paper reports the first step of the development, which is the development of a method to estimate solar irradiance of urban buildings. The most significant feature of the method is that the method adopts the idea that “whether the sun can see us or not” indicates “whether we have sunshine or not” for calculation of solar irradiance of a point on a building surface. Utilization of projection images viewed from the sun created by using computer graphics (CG) techniques such as the Z-buffer algorithm makes our system much less computation time than most of existing systems using a hemispherical viewsheds or that of ray tracing. Results of an experiment conducted in Yokohama of Japan demonstrate that the method would be able to estimate solar irradiance on not only roofs and but also facades of urban buildings using LOD2 building data in Japan accurately enough.