homehome Home chatchat Notifications


MIT Wi-Fi technology can see you through walls

Researchers at MIT have developed a device that can track human silhouettes behind walls using Wi-Fi.

Mihai Andrei
November 2, 2015 @ 5:13 am

share Share

Researchers at MIT have developed a device that can track human silhouettes behind walls using Wi-Fi. The device called RF-Capture emits out Wi-Fi signals and then tracks back the reflections and see if together, they piece a human form.

This is what the RF-Capture “sees”. Note that it only detects some parts of the human body. Image credits: MIT.

Wi-Fi is a local area wireless computer networking technology that allows electronic devices to connect to each other, generally using the 2.4 gigahertz (12 cm) UHF and 5 gigahertz (6 cm) SHF ISM radio bands. But Wi-Fi can do more than create networks and connecting you to the internet – as a new study just showed, it can send out a signal and reconstruct what’s “on the other side” – see what reflected the signal back. This can generally be done with every type of wave, but high frequency waves provide better resolution and Wi-Fi is a cheap and generally available technology, which makes it more attractive to use.

Here’s how this works: RF-Capture is placed in a room, and starts emitting signals; a part of the signal bounces back off the walls, but some of it passes through and gets to the neighboring room. If someone is walking in the neighboring room, then the signal is again reflected by the human body and returns to the Wi-Fi device; only some of the body parts create significant reflections. The technology could be used in the houses of elder people or people with disabilities to see if they have fallen or if they are injured and need help. It can also be used in smart homes, to detect movements that control the appliances in the house. It can identify people and see if they are making certain gestures. Here’s a video showing how it works:

How it works. Image via MIT.

The sensibility is absolutely amazing! Being able to detect movements with the same accuracy as a kinect camera placed right in front of the subject is absolutely spectacular.

The concept itself is not new – it’s something that has been used in geophysics for decades, for example in ground penetrating radars, a technology that can detect buried near-surface objects. But the application is entirely different, and holds a lot of potential, because Wi-Fi is basically ubiquitous in the developed world.

share Share

The world’s largest wildlife crossing is under construction in LA, and it’s no less than a miracle

But we need more of these massive wildlife crossings.

Your gold could come from some of the most violent stars in the universe

That gold in your phone could have originated from a magnetar.

Ronan the Sea Lion Can Keep a Beat Better Than You Can — and She Might Just Change What We Know About Music and the Brain

A rescued sea lion is shaking up what scientists thought they knew about rhythm and the brain

Did the Ancient Egyptians Paint the Milky Way on Their Coffins?

Tomb art suggests the sky goddess Nut from ancient Egypt might reveal the oldest depiction of our galaxy.

Dinosaurs Were Doing Just Fine Before the Asteroid Hit

New research overturns the idea that dinosaurs were already dying out before the asteroid hit.

Denmark could become the first country to ban deepfakes

Denmark hopes to pass a law prohibiting publishing deepfakes without the subject's consent.

Archaeologists find 2,000-year-old Roman military sandals in Germany with nails for traction

To march legionaries across the vast Roman Empire, solid footwear was required.

Mexico Will Give U.S. More Water to Avert More Tariffs

Droughts due to climate change are making Mexico increasingly water indebted to the USA.

Chinese Student Got Rescued from Mount Fuji—Then Went Back for His Phone and Needed Saving Again

A student was saved two times in four days after ignoring warnings to stay off Mount Fuji.

The perfect pub crawl: mathematicians solve most efficient way to visit all 81,998 bars in South Korea

This is the longest pub crawl ever solved by scientists.