A San Francisco Bay Area resident living beneath one of SFO's primary departure corridors has constructed a real-time ceiling projection system that maps ADS-B transponder data from overflying aircraft directly onto interior surfaces of their home, creating a live, overhead visualization of traffic as it climbs out from the airport. The project uses a software-defined radio (SDR) receiver — the same class of inexpensive hardware used by hobbyists running platforms like FlightAware feeders and dump1090 — to decode 1090 MHz ADS-B Out squitter messages broadcast by equipped aircraft. The decoded position, altitude, speed, and identity data is then fed into custom projection-mapping software that renders each aircraft's track across the ceiling in real time, scaled to geographic position relative to the house.
The technical achievement, while framed as a home art project, underscores a fundamental characteristic of ADS-B Out that professional pilots and operators should internalize: the data is entirely unencrypted and publicly receivable by anyone with commodity hardware costing less than thirty dollars. Every ADS-B Out transmission — mandated in U.S. airspace under FAR 91.225 since January 2020 — broadcasts aircraft identity via squawk and tail number, GPS-derived position, pressure altitude, groundspeed, and track. There is no authentication layer and no transmission filtering by receiver class. A hobbyist's SDR dongle receives the same datastream as an FAA ground station. This has long been understood within the aviation community, but projects like this one make the accessibility viscerally concrete for a general audience.
For operators flying under Part 91, 91K, or 135 — particularly those transporting high-net-worth individuals, executives, or other principals with security considerations — this reality carries direct operational implications. Flight tracking aggregators such as FlightAware, Flightradar24, and ADS-B Exchange compile these publicly received signals into searchable, historically queryable databases. While the FAA's Privacy ICAO Address (PIA) program and the LADD (Limiting Aircraft Data Displayed) opt-out mechanism exist to reduce exposure on commercial aggregator platforms, they do not prevent raw ADS-B reception by independent receivers. An operator who assumes that a tail number block or a LADD enrollment provides meaningful operational security is working with an incomplete threat model. Aircraft operating under PIA programs use randomized ICAO hex codes that rotate, but correlation attacks using departure airport, timing, and destination data can often re-identify flights.
The SFO context is also operationally notable. SFO operates four runways in a configuration heavily constrained by San Francisco Bay geography, NIMBY noise abatement pressure from communities in Millbrae, San Bruno, and South San Francisco, and complex interactions with Oakland (KOAK) and San Jose (KSJC) approach/departure corridors. The primary departure routes — the PORTE, TRISS, and BSR transitions among others — funnel high volumes of heavy and super-heavy traffic over dense residential areas at relatively low altitudes during the initial climb segment. The density of ADS-B-equipped traffic on these corridors, combined with the low slant range from ground receivers, means an SDR installation directly beneath a departure path receives an exceptionally clean, high-update-rate datastream — essentially ideal conditions for a project of this kind.
The broader trend illustrated here is the commoditization of surveillance-grade aviation situational awareness. Tools and visualizations that would have required six-figure infrastructure investments a decade ago are now achievable with open-source software, a Raspberry Pi, and a twenty-dollar USB dongle. Academic researchers, journalists, investigative nonprofits, and government agencies worldwide already exploit public ADS-B feeds for everything from tracking military aircraft movements to monitoring sanction evasion by private jets. For the professional aviation community, the takeaway is not that ADS-B is a flawed mandate — its safety benefits in traffic situational awareness and ATC surveillance are well established — but that operators, flight departments, and their security advisors must treat position broadcasting as a public act and plan accordingly when mission profiles demand discretion.