Celestial compass design mimics the fan-like polarisation filter array of insect eyes

Sensor prototype mounted on robot. Credit: Robert Mitchell.

Abstract

Insects use the sun’s position (even when concealed) as a compass for navigation by filtering celestial light intensity and polarisation through their compound eyes. To replicate this functionality, we present a sensor that imitates essential aspects of insect eyes, particularly the fan-like arrangements of polarised light receptors in their dorsal rim area. Our sensor comprises a ring of just eight polarimeter devices (pairs of photodiodes evaluating two orthogonal polarised light orientations) to analyse the skylight coming from different directions. Because the layout of our sensor aligns with the polarised light pattern in the sky, a simple computation that integrates information spatially across the devices allows accurate extraction of the sun’s position. In extensive validation encompassing various occlusions from trees and buildings, as well as diverse atmospheric and weather conditions, our sensor exhibited superior performance compared to alternative (and computationally more complex) methods

Publication
preprint
Evripidis Gkanias
Evripidis Gkanias
Research Associate in Computational & Neuromorphic Modelling

Post-doctoral research associate at the University of Edinburgh, School of Informatics, and the University of Groningen, Faculty of Science and Engineering.

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