Designers of an electronic collar to prevent poaching of big game in Africa share the story of their still-evolving efforts.
Illegal poaching is a major contributor to declining populations of endangered animals around the world. For example, it’s estimated there are now less than 500,000 elephants in Africa, less than half of the population 40 years ago. If the pace persists, wild elephants are at risk of extinction.
This problem spawned a collaboration between the two of us, an engineer and a wildlife biologist. Our vision of a solution came together when we combined our respective areas of expertise in acoustic shot detection and radio tracking of animals.
Together we created a scalable gunshot detection system for wildlife we call Wiper which stands for wireless anti-poaching collar for elephants and rhinos. It’s a novel sensor that aims to disrupt poaching by monitoring an animal wherever it may roam.
The majority of existing solutions are based on ground or aerial sensors that can be ineffective for an elephant’s immense range of movement. Wiper combines two modes of sensing--behavior-change-based alerts and acoustic-shot detection. Together they deliver a near 100-percent shot detection rate.
By pairing technologies that monitor animal behavior like GPS tracking collars with our own acoustic sensors, we are able to immediately identify the occurrence and location of gunshots. Immediately following this detection, authorities are notified through cellular or Iridium modems and deployed to the area.
Other devices depended on muzzle-blast detection to flag gunfire activity to authorities. Our innovation relies on ballistic shockwave detection so it can’t be fooled by poachers with gun mufflers or silencers.
Power consumption is a top challenge for the dual sensor Wiper that needs to last two years. (Image: Authors)
Ballistic shockwaves have a unique n-wave pattern which exhibits high energy, short duration and very fast rise times. Paired with GPS tracking collars to identify the location of the incident, the shockwave of the bullet is detected even before the muzzle blast reaches the animal.
Power management is critical for Wiper. An early human-wearable detection system could only run 12 hours on a single charge, but our animal sensors needed to last two years.
We are working to balance several factors. Making reliable detection is harder with less power. At the same time, false alarms would quickly discredit the system and make it useless. One approach to extending battery life is duty cycling, but this application requires continuous monitoring because we cannot afford to miss the first shot--the second might be aimed at the sensor itself.
The sensors we currently use are based on sniper detection technology originally developed for protecting dismounted soldiers. We know it’s easy to get cornered into looking for solutions for a specific problem, while the most innovative and impactful breakthroughs often come from taking a fresh perspective.
Wiper was fortunate to win second place in the 2017 Vodafone Americas Foundation Wireless Innovation Project, a competition to help fund wireless technologies that address critical social issues. We are using our $200,000 prize to develop and test our prototype. We envision this sensor integrated into large mammal units tracking thousands of animals a year globally.
To the members of the broader engineering community who are working to make their solutions a reality, we offer this advice: there are people who will find your passion inspiring and want to help with the work you’re doing, so continue to find ways to bring your ideas to life.
--Ákos Lédeczi is a professor of computer engineering at Vanderbilt University. George Wittemyer is an associate professor in the department of fish, wildlife and conservation biology at Colorado State University. Together they are designing Wiper.