Robot Localization Using a Computer Vision Sextant

This paper explores the possibility of using Sun altitude for localization of a robot in totally unknown territory. A set of Sun altitudes is obtained by processing a sequence of time-indexed images of the sky. Each altitude constrains the viewer to a circle on the surface of a celestial body, called the circle of equal altitude. A set of circles of equal altitude can be intersected to yield viewer position. We use this principle to obtain position on Earth. Since altitude measurements are corrupted by noise, a least-square estimate is numerically calculated from the sequence of altitudes. The paper discusses the necessary theory for Sun-based localization, the technical issues of camera calibration and image processing, and presents preliminary results with real data.

• Type: Conference
• Year: 1995
• Where: ICRA
• Authors: Fabio Gagliardi Cozman, Eric Krotkov
• Keywords: Altitude Measurements, Equal Altitude, ICRA 1995, Robotics, Sun Altitudes