Originally Posted by
wealthysoup
In a simple form: How flightradar generally works for GA aircraft is it requires several ground stations to receive the transponder signal from an aircraft. It then calculates based on the known locations of the ground stations and the differences in the time received between the transponder signal at each of these locations. Over time it can estimate the altitude, speed and direction of the aircraft. For a really basic example of this; turn off your GPS, wifi and bluetooth on your phone and open google maps and look at the margin of error circle around your position.
A lot of the accuracy of this system depends how accurately a user records the positon of their flightradar receiver (typically done manually) and how many different receivers receive each transponder transmission.
Yes it is called MULTILATERATION and works in time-domain just like
the GPS. True is that data is not accurate like WAAS assisted aviation
GPS (better than 7,5 m x,y,z error) but it is within 50 m of real x,y,z
in relation to WGS84 so that z may be in question to real ground but
not in relative loss of high. FR "radar site" is getting time and positon
from GPS running full time like this:
DEVICE INFO: MAC ADDRESS: S/W VERSION: FR24-3.8,101,66 F/W VERSION: 21 ROOT DEVICE: /dev/mmcblk0p2 RADAR CODE: F-AAAA1 UPTIME: 0 days 13:50:11 GPS INFO: POSITION: XX, YY, 10.7m [AMSL] TEMPERATURE: 38.09'C GPS EXTENDED STATUS: Latitude: XX Longitude: YY Altitude: 10m Decoding status: doing fixes Antenna present: YES Antenna port shorted: NO Satellites used: 8 Signal levels: 02=51.0 06=50.0 0C=51.0 0E=48.0 18=43.0 19=55.0 1D=49.0 1F=35.0 20=50.0 STORAGE: ROOT PARTITION USAGE: 103M/622M (18%) USER PARTITION USAGE: 1.6M/120M (2%) STATUS: RECEIVER SOFTWARE: ON RAW FEED [30334]: UP, NUM CONNECTED: 0 BS FEED [30003]: UP, NUM CONNECTED: 0 FR24 CONNECTION STATUS: ADS-B: connected, 4 AC tracked ModeS: connected, 6 AC tracked