Threats

GNSS Jamming

Radio-frequency interference intentionally transmitted to overpower or degrade a GPS/GNSS receiver's ability to acquire or track satellite signals, denying accurate position and timing rather than falsifying it. Operating, marketing, selling or importing a jamming device in the United States is a federal crime under the Communications Act, enforced by the FCC — there is no personal, business, or vehicle-use exemption.

GNSS Spoofing

Broadcasting counterfeit GNSS signals that a receiver accepts as genuine, causing it to compute a false position, velocity, or time rather than losing its fix outright. The FAA has issued public Safety Alerts For Operators (SAFOs) advising flight crews to expect and cross-check for spoofing in specific geographic areas.

Group 1 UAS

The smallest DoD-published UAS weight class — hand-launched or hobbyist-scale multirotor and fixed-wing aircraft weighing 20 lb or less, normally flown below 1,200 ft above ground level at under 100 knots. This is also the weight band most consumer/commercial small UAS (sUAS) sold in the United States fall into.

Group 2 UAS

Small tactical UAS heavier than Group 1 but still under 55 lb — the same upper weight bound the FAA uses for its small-UAS (sUAS) rule (14 CFR Part 107) — normally operated below 3,500 ft AGL at up to 250 knots.

Group 3 UAS

Tactical UAS weighing up to 1,320 lb, normally operated below 18,000 ft mean sea level (the U.S. instrument-flight-rules Class A airspace floor) at under 250 knots. This is the first group where DoD doctrine switches the altitude reference from AGL to MSL.

Group 4 UAS

Larger UAS exceeding 1,320 lb but normally operated below 18,000 ft MSL, at any airspeed — the DoD-published class boundary that separates Group 4 from the Group 3 weight ceiling below it and from Group 5's higher-altitude regime above it.

Group 5 UAS

The largest and highest-flying DoD-published UAS class — aircraft exceeding 1,320 lb normally operated above 18,000 ft MSL, at any airspeed. This is the class the U.S. Air Force's own publicly released MQ-9 Reaper fact sheet describes as operating up to 50,000 ft.

Remote-ID-Compliant Small UAS

Small unmanned aircraft complying with the FAA's Remote Identification rule (14 CFR Part 89, effective September 16, 2023), which requires most drones to broadcast identification, location, altitude, velocity, and control-station location — functioning as a digital "license plate" that any nearby receiver can pick up, similar in spirit to (but a distinct standard from) ADS-B for crewed aircraft.

Swarm / Multi-UAS

Coordinated operation of multiple UAS — from simultaneous multi-aircraft flights to autonomous, distributed swarming behavior — identified in the Department of Defense's publicly released 2021 Counter-Small Unmanned Aircraft Systems Strategy as a growing category of concern distinct from single-aircraft incursions, because it can saturate detection and response capacity built for one aircraft at a time.