A tech enthusiast named Blinry took a week-long dive into the world of software defined radio (SDR), discovering the invisible universe of electromagnetic signals surrounding us. Using a $30 USB dongle and some wire, he accessed a treasure trove of radio communications.
Blinry decoded images from weather satellites, viewing Earth in real-time, and tracked a weather balloon into a swampy forest. He intercepted data from neighbors' sensors and utility meters. He listened to number stations and a Russian "buzzer" signal ("The purpose of the station is unclear, but most theories think it's military communication.").
He used a smartphone's NFC signal to send Morse code through walls and detected when someone turned on a smartphone across the apartment. He received Morse code from an Italian satellite, and accidentally picked up tire pressure data from passing cars.
"I was amazed how much invisible communication is going on around us in the electromagnetic spectrum at the same time," he says.
Previously:
• GNU Radio: the universal, software-defined radio
• Cities' emergency sirens will play anything you send them over an unencrypted radio protocol
