Raspberry Pi 5 + RTL-SDR Adventures

This week we dove into the Raspberry Pi 5 paired with the RTL-SDR USB receiver — a combination that puts the entire radio spectrum at your fingertips, from shortwave and ham signals to weather satellites, aircraft telemetry, and global digital networks. Our main focus: decoding Inmarsat and Iridium satellite transmissions.

Hardware

• Raspberry Pi 5 (8 GB recommended) + official power supply
• RTL-SDR Blog V3 or compatible USB SDR
• High-speed microSD card (32 GB+)
• External antenna — discone, dipole, or active L-band patch for satellite reception
• Optional cooling case/fan for long decoding sessions

Software

• GQRX, SDR++, or CubicSDR for general listening
• GNU Radio and gr-satellites for advanced processing
• JAERO for Inmarsat AERO channels
• Iridium Toolkit for Iridium bursts
• Direwolf or multimon-ng for packet/telemetry experiments

Decoding Inmarsat & Iridium

Inmarsat satellites sit in geostationary orbit transmitting aeronautical safety messages and weather; with a tuned L-band antenna and JAERO you can decode them right from the Pi. Iridium forms a low-Earth-orbit network with truly global coverage — the Iridium Toolkit lets you visualize and analyze downlink bursts. A few hundred dollars of hardware goes a long way.