Proposition of 3D measurement method using shadow for planetary surface exploration - shadow range finder: SRF

In this paper, we propose the Shadow Range Finder (SRF), which can make good use of shadows for the measurement of surface information under direct sunlight. The shadow is stable, and can be recognized in the case of halation. The SRF uses a single camera, which should be installed on a manipulator for sampling, and a manipulator link, which produces its shadow on a measured surface. The principle of the SRF is the same as that of a Laser Range Finder, except that a shadow is used for the scanning slit instead of a laser. In this paper, we present measurements of a real object, such as a stone, and evaluate the validity of the SRF.