How it works

Signals from aircraft within observed radio coverage, usually line of sight. This is a local view, not a complete flight census.

It may not transmit position, may be out of range, or terrain and buildings may block the signal. Low aircraft can be especially hard to receive.

Commercial sites combine many receivers and other sources. This site reports one community receiver's observed addresses and positions.

Aircraft altitude, terrain, obstructions, radio conditions and receiver coverage all matter. A missing aircraft is not proof that no aircraft is there.

No. Airport observations and alerts come from NWS; radar and satellite imagery come from IEM using NOAA data. Observation/frame valid time differs from fetch time and from aircraft timestamps.

PC scanner voice streaming is forthcoming until a stream is configured. Audio is a separate feed, never automatically matched to a selected aircraft.

Exact antenna and home coordinates stay private. Near Bristow uses the approximate public town center. Receiver-distance records use a different reference.

No. Military database flags are identification clues only. Rotorcraft tags use transmitted category or known type codes; no police, medical, occupant or mission claims are inferred.

Photos, chat and a native app are future scope. After publication, Safari's Add to Home Screen can open this mobile website in an app-style window; current data still needs internet access.

Callsign is a transmitted operational identifier, registration is a tail number when supplied, and hex is the ICAO transponder address. Addresses may be anonymized; none alone verifies a flight or owner.

ADS-B broadcasts aircraft state including position. Mode S is transponder communication and does not always supply position. ACARS is a separate digital message datalink; not every message contains a location.

This site currently uses 1090 MHz data. ADS-B can also use 978 MHz UAT in the United States; no installed 978 receiver is claimed here.

Aircraft altitude here is barometric pressure altitude, uncorrected for local pressure. It is not height above your house; no terrain or QNH correction is applied.

No. Ground speed measures motion over the Earth. Airspeed measures motion through the air; wind can make them different. This site shows ground speed in mph and knots.

No. Ground track is the direction of movement over the Earth. Wind can cause the nose to point in a different direction. Map rotation follows ground track.

Accepted local radio frames per second, not aircraft per second. One aircraft can transmit many frames.

A received signal-strength measurement relative to the receiver's digital full scale. It is not a distance estimate or an absolute comparison across stations; aircraft mix also affects the mean.

Unique counts are distinct received addresses, not verified airframes or flights. First seen today means new to the receiver's records. Today uses America/New_York midnight.

An address heard in several hours is counted in each hour but only once in the daily total. Future hours are excluded from busiest-hour highlights.

Contacts are receiver-observed reception spans separated by a 90-second gap. They are not verified flights. Observed track duration is not full flight duration.

Receiver reception distance, not distance from your house. Other records describe observed altitude, ground speed, reception span and simultaneous tracking, not complete flights.

Messages can be coded and airline-specific; this site shows received text literally without automatic translation, guessed routes or fabricated associations to aircraft positions.

The newest 100 received messages are public. The full retained archive remains on the Pi, up to seven days / 20,000 messages. ACARS update time is independent of fresh ADS-B positions.

The public snapshot is polled about every 15 seconds. Positioned aircraft ages must be at most 60 seconds; the site marks snapshots stale after 90 seconds or a failed refresh, retaining last known values without demo fallback.

When the Pi archive update is installed. Actual samples are recorded about every 30 seconds and retained 24 hours. No earlier tracks are invented, and gaps over 90 seconds are not interpolated.