Regional NYC: helicopter traffic from 11 airports, with sound
Replay and noise-map design: created by Allen Shaibani (publicworks.nyc) as Chopper Noise, whose published method and per-type loudness table this tab uses (original code BSD 3-Clause licensed). This version was written independently for this dashboard from the original's documented behavior; any mistakes in it are not the original's.
How this is calculated, sources and limits
Helicopters are aircraft the operations data classes as rotorcraft. A flight is a run of airborne pings (every 5 seconds, replayed from a 10-second sample) that has a takeoff or landing at one of the airports above in the operations data. The level at a block is L(r) = L150 − 20 log10(r / 150) − 2 (r − 150) / 1000 dBA, r being the straight-line distance in metres (never under 30) and L150 the aircraft type's peak level at 150 m; height is pressure altitude corrected with the hourly Newark altimeter setting. Rings show how far each helicopter's level reaches the ground. A block lights when 60+ dBA reaches it and fades to a third in 60 seconds of the day.
Groups: tour operators are FlyNYON, Zip Aviation, New York Helicopters and HeliNY; public service is police, military and government owners; every other operator is "other". These rest on operator and owner names and are a first cut.
- Levels are modeled outdoor peaks. No measured flyover has checked them. Buildings and the direction the helicopter faces are ignored.
- Flights are only followed where radio receivers pick them up; coverage over open water off the coasts is thinner than over land, so some offshore stretches may be missing.
- Only flights with a recorded takeoff or landing at the 11 airport codes are shown, and only while inside the map box. Other helicopter traffic is not included.
- Residents are counted where they live, not where they were. "Heard" means the modeled level reached the block.
- Whole day: for each flight (with the Flights and Airport choices applied), the loudest level it brought to each block, from its 10-second track points and the points halfway between them (about every 5 seconds); a block's colour is the number of flights that reached it at the chosen level. Residents are counted once however many flights they heard.
- Passengers: ADS-B does not report who is on board. The panel counts the passenger seats of each helicopter in the air (the maker's standard configuration for its type, pilot not counted), so it is the most people who could be aboard, not a count. Police, military and other public-service flights and helicopters of unknown type are left out.
Sources: aircraft positions and takeoffs/landings from ADS-B data (ADS-B Exchange); loudness per aircraft type from the UK Civil Aviation Authority helicopter noise database via Chopper Noise by Allen Shaibani; residents from the 2020 Census redistricting data; altimeter from the Iowa Environmental Mesonet (station EWR); airport locations from OurAirports.