A microwave radar to raised detect and shield polar bears

A symbol of global warming, the polar bear is on the International Union for Conservation of Nature’s red list for its vulnerable status. It is particularly threatened by melting ice and fragmentation of the ice floe, which complicate the hunting efforts of this large white carnivore.

In the North, oil exploration and development activities also pose a threat to females and their young, invisible in their burrow several meters below the ice.

To better protect the species, the researchers are trying to face a major challenge: identifying from a helicopter where the occupied burrows are. The aim is to limit disturbances around them when the puppies are most vulnerable.

The Far North broke heat records during winter 2021/2022.

Photo: Associated Press/David Goldman

For this, researchers at Simon Fraser University in British Columbia adapted a Synthetic Aperture Radar (SAR). This radar uses microwaves, which can penetrate dry ice, says Bernhard Rabus, a professor at the university’s School of Engineering and Applied Sciences and an expert on synthetic aperture radars.

The microwaves emitted by the radar are sent back differently if it encounters a bear or the ice and snow that surround it, which allows researchers to detect its presence, argues Bernhard Rabus.

Detecting more than one in two dens?

Students at Simon Fraser University recently tested the radar in Norway to try to gauge its effectiveness. They worked on the project in partnership with Brigham Young University, USA, ARTEMIS Inc. and Polar Bears International.

Analysis of the images obtained is still ongoing, but the researchers hope to eventually be able to identify more burrows than with commonly used frontal infrared imaging techniques. This method, which is mainly used in Alaska by oil companies, misses 55% of bear dens, according to a study carried out on the subject. (New window)

This is still an active quest, we can only wait at this point.says Bernhard Rabus.

The research seeks to confirm the usefulness of SAR for detecting occupied bear dens from a distance by helicopter.

Photo: Submitted by Jeff Stacey

large-scale challenges

If this radar holds promise, Ian Stirling doubts it could be used on a larger scale to assess, for example, the reproductive success of bears, taking into account climate change and other environmental factors.

Its low density in the territory makes it very difficult to study species outside a given sector, he explains. I’ve done a lot of research in the Arctic and it can take a lot of money and a lot of time to identify a very small number of bears because they are very, very dispersed.he explains.

That said, this tool could have significant potential for the conservation of the species in specific areas where human activities could have a significant impact on bear breeding activities.

Knowing where the bears are can be very important to avoid disturbing them during the critical period when they are in their den. Once they’re gone, it doesn’t really matter what noise we make, or anything.he argues.

But knowing where polar bears are is still important for avoiding them, which can be useful for their conservation.designs Ian Stirling.

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