In The Air And On The Air Aviation Radio Systems -

In this presentation at the DEF CON 27 TransportHax Village, Exploding Lemur (Nick) provides an educational overview of aeronautical radio frequencies, avionics protocols, and how hackers can monitor aviation communications using low-cost Software-Defined Radios (SDR). He starts at 04:00 by detailing VHF AM voice communications across the 118–137 MHz band, explaining how Air Traffic Control (ATC) towers, automated terminal information services (ATIS), and pilot unicom channels operate.

Nick examines transponder surveillance systems at 08:00, breaking down secondary surveillance radar, Mode A squawk codes, Mode C pressure altitude encoding, and Mode S interrogation. At 12:00, he discusses ADS-B data streams broadcast over 1090 MHz and contrasts them with satellite-delivered weather services like SiriusXM Aviation. He details satellite navigation architecture at 16:00, explaining how GPS time beacons and WAAS (Wide Area Augmentation System) differential signals ensure precise aircraft positioning.

At 20:00, Nick reviews Distance Measuring Equipment (DME), explaining its pulse ping-and-reply mechanics between airborne transceivers and ground stations. He wraps up at 24:00 by demonstrating how to build a dedicated dual-dongle SDR monitoring station to capture both 1090 MHz Extended Squitter and 978 MHz Universal Access Transceiver (UAT) broadcasts, highlighting essential bandpass filters and antenna considerations at 28:00. (AI summary — Gemini Flash)