Also known as: RTCA
RTCA is a United States standards organization for aviation electronics. Its DO-260 series of Minimum Operational Performance Standards (MOPS) defines the ADS-B requirements that aircraft transponders must meet, alongside the international standards from ICAO.1
Overview
RTCA — historically the Radio Technical Commission for Aeronautics — is a US private, not-for-profit association that develops consensus technical standards for aviation, working closely with the Federal Aviation Administration, which frequently adopts RTCA documents by reference in its regulations. Its output takes the form of DO- documents, most importantly the Minimum Operational Performance Standards (MOPS) that specify how a piece of avionics must behave and perform to be certified. Where ICAO sets the high-level, worldwide what — the message formats and required capabilities in Annex 10 — RTCA writes the detailed, testable how for the US market.
For surveillance, two RTCA documents matter to anyone receiving aircraft signals. DO-260 (with revisions DO-260A and DO-260B) is the MOPS for 1090 MHz Extended Squitter ADS-B, riding on Mode S; the revision letter denotes successive versions of the message set and integrity reporting, and equipment or decoders often state which version they implement. DO-282 is the parallel MOPS for the alternative Universal Access Transceiver (UAT-978) ADS-B link used at 978 MHz by general aviation in the United States. RTCA’s standards are deliberately harmonised with their European counterparts from EUROCAE — DO-260B corresponds to ED-102A — so that avionics work interchangeably on both sides of the Atlantic, which is essential for international flight.
Relevance to SDR
RTCA’s DO-260B is the document most often cited in ADS-B decoder documentation, because it is the precise definition of the bit-level message formats a receiver must parse: the Extended Squitter types, the position and velocity encodings (including Compact Position Reporting), and the integrity fields. When an open-source decoder note says it “implements DO-260B”, it means it handles that version’s full message set. For the 978 MHz UAT link common on US light aircraft, DO-282 plays the same role, which is why UAT decoders and 1090 MHz decoders are effectively separate implementations of two different RTCA standards.
Aircraft surveillance is outside GopherTrunk’s land-mobile trunking scope, so GopherTrunk does not decode ADS-B itself — dedicated 1090 MHz and 978 MHz tools do that — but RTCA is worth knowing as the authority that pins down exactly what those signals contain. See the other signals you’ll meet lesson for where ADS-B sits among the wider set of receivable signals.