Volcano Watch: Terrestrial laser scanning of Halemaʻumaʻu

  • Main frame: A composite of the point clouds resulting from HVO’s terrestrial laser scanning surveys of Halemaʻumaʻu crater since January 2021, viewed from the southwest. The central region of the crater, including the lava lake, is reliably captured in all surveys. Further afield the point clouds become sparser, as the laser reflections from such distances and angles escape detection by the instrument. Inset frame: The terrestrial laser scanning instrument rotates through a scan on the south rim of Halemaʻumaʻu on June 10, 2021.

A technique called structure-from-motion then uses motion parallax to construct a two-dimensional map or three-dimensional model of the area by matching the same features across multiple images.