Study on insect vision could lead to new navigational aids
HUNTSVILLE, Alabama: Development of a virtual reality-like projection system to study insect vision could eventually provide the US Air Force with a new type of navigation system.
The University of Alabama in Huntsville (UAH) is the lead institution partnered with Polaris Sensor Technologies Inc. of Huntsville in a three-year grant to test various screen materials and then design and build an insect experiment scene projection system for the Air Force.
The Air Force is interested in learning how insects use polarisation vision, says Dr Don Gregory, UAH distinguished professor of physics. Polarisation involves the geometrical orientation of light wave oscillations, a property the insects detect and use somehow to direct themselves.
“Many insects can see and use optical polarisation. For example, some insects can see the partial polarisation pattern in the sky, which we cannot see without instruments. So think about scenarios in which GPS is not available, such as at the bottom of ‘urban canyons.’ How do you navigate?” asks Dr Gregory.
“Some insects, including bees, ants and locusts, navigate by sensing the celestial polarisation pattern, and it would be pretty cool to understand how they do that and exploit the mechanism to deal with GPS-denied situations.” To figure out how the insects exploit polarisation and colour vision, Air Force scientists first need an experimental environment that provides realistic visual stimuli for the insects.
“We want the insect to think it’s outside,” Dr Gregory says. There are two challenges to making that happen. First, the screen used to create the environment has to accurately represent the light spectrum and polarisation that is input into it during an experiment. Secondly, the screen refresh rate must be above the rate at which the insect under test experiences smooth motion rather than merely a series of images refreshing, called its flicker fusion frequency.