Drone or aircraft? How to tell the difference
Distinguishing drones from aircraft, helicopters, and other objects is especially challenging at night. This guide explains the key characteristics so you can make an informed assessment — and shows how Sky Lens helps you confirm it.
Lighting is the most reliable indicator — but only if you know what to look for. ICAO standards are mandatory worldwide for aircraft; drones have no equivalent requirement.
Aircraft
Red navigation light on the left wing · Green on the right · White strobe every 1–2 seconds · White tail light steady. This is ICAO standard, legally required for all aircraft. The strobe is the most recognisable indicator at distance.
Helicopter
Same navigation lights as fixed-wing aircraft (red left, green right, white strobe) plus a red anti-collision light on top that rotates or flashes. Helicopters can hover and fly much slower — and the distinctive rotor chop is unmistakable.
Drone
No standardised lighting required. Often white or coloured LEDs on the arms. Some models carry a red or green strobe, but this is not legally prescribed. Light patterns vary widely by manufacturer and model.
Satellite
No light source of its own — reflects sunlight. Appears as a steadily moving point with no flicker whatsoever. Only visible during twilight (30–90 min after sunset or before sunrise) when the satellite is still in sunlight while the ground is dark.
Sound is a powerful — and often underestimated — indicator. The pitch, volume, and carry of the noise tell you a great deal about the type of object.
Jet aircraft
Audible at 15–25 km. Deep roar or whine depending on phase (climb, cruise, descent). The sound always lags behind the visible object because of the speed of sound.
Propeller aircraft
Audible at 5–10 km. Recognisable propeller drone — a periodic, slightly buzzing growl. Small sport planes sound different from large turboprops.
Helicopter
Distinctive blade-slap from the rotor — unmistakable. Audible at 8–12 km depending on wind direction. The tail rotor adds a high-pitched secondary sound.
Drone
High-pitched buzzing propeller noise, similar to a swarm of insects but more mechanical and even. Audible to only ~200–400 metres. Beyond that: completely silent, even if the object is visible.
Satellite / planet / star
Completely silent. If the object moves but you hear absolutely nothing, and it is high in the sky — a satellite or celestial body is far more likely than a drone or aircraft.
Movement pattern is one of the most distinctive characteristics. Watch carefully for speed, direction, consistency, and whether the object can hover.
Aircraft
Straight line, constant speed. Apparent speed increases as it passes (perspective effect): an approaching jet seems to stand still, then passes quickly. No turns, no hovering.
Helicopter
Can hover, fly backwards, and change direction sharply. Typically flies slower than a fixed-wing aircraft. Can also circle over a location.
Drone
Can hover — the most distinctive behaviour. Sudden direction changes are possible. Maximum speed of consumer drones is limited (typically 40–70 km/h). At altitude, hard to distinguish from an aircraft in a banked turn.
Satellite
Steady movement in a straight arc from horizon to horizon in 2–6 minutes. No course change possible. Fades gradually (entering Earth's shadow) or disappears abruptly beyond the horizon.
Drone policy in the European Union follows EASA standards. Categories determine where, how high, and with which drone you may fly — and what registration is required.
Registration requirement
All drones above 250 grams must be registered with the national aviation authority. The pilot must also pass a theoretical exam for category A2 and above. Most jurisdictions outside the EU have equivalent frameworks.
Categories
Open A1: max 250 g, may fly over people, max 120 m. Open A2: 250 g–4 kg, horizontal safety distance from people, max 120 m. Open A3: 4–25 kg, far from people, max 120 m. Specific category: anything outside the Open Category requires separate authorisation.
Electronic identification (Remote ID)
Drones above 250 g must be equipped with Remote ID — a system that continuously broadcasts the drone's identity, position, altitude, and speed. This is analogous to ADS-B for aircraft, but on a different frequency band.
Enter your location and the time of your sighting. Sky Lens checks ADS-B, satellite orbits, and star positions to confirm what was overhead at that moment.