Map

Click on the layers icon (upper righthand corner of map) to choose the base map and select other general mapping options:

Click on the button (upper righthand corner of map) to recenter the map on the Madison airport

Sound Meters

• The number in the circle shows the most recent decibel reading for the sound meter.


• The color and size of the marker changes with the decibel reading:

• The number in the marker changes to white if the most recent reading is more than 5 seconds old:

• The marker looks like this if no data has been received within the last 10 seconds:

Aircraft

• Aircraft markers show the type of aircraft, and are colored by altitude:

• By default, aircraft above 10,000 ft or more than 25 miles from the airport are filtered out. This can be changed in the Aircraft Filters area to show more aircraft.


• Click on a marker (or on a row in the sidebar table) to get more details (see below) about a particular aircraft. Click again on the call sign in the details box to keep the map centered on the selected aircraft.
  
  
• Aircraft details include the following:
• Tail number (e.g. 'N571QS'). Can be looked up here for details about the aircraft.
• Call Sign —
• for commercial flights, this will be listed as an abbreviated version of the airline followed by the flight number
• for non-commercial aircraft this will usually be the same as tail number
• ICAO (or Mode-S "hex") code — a unique code assigned to each aircraft. (See here.)
• Altitude (in feet) as indicated by the aircraft's altimeter
• Speed (in knots*) — this is normally the speed over ground, not the indicated speed through the air (airspeed)
• Position and distance (in nautical miles*) from the Madison airport
• Track — the direction (in compass degrees) that the aircraft is heading
• Age — the number of seconds since the last ADS-B signal was received



(*1 nautical mile = 1.15 statute miles; 1 knot = 1 nautical mile per hour)