That means Turkey is limited to 32767 planes - yes?
Turkey /(TC) apparently; five bits encode each letter of the suffix, 1 means A, 26 = 0x1a means Z. Their allocation (0x4b8000) has 15 bits, so this just fits.
jwoolard: do you know any other country than N and HB which have an algorithmic mapping from registration to mode S address?
No - those are my 'some'. I would guess that many countries implemented it this way - it makes the assignment process much easier.
jwoolard: do you know any other country than N and HB which have an algorithmic mapping from registration to mode S address?
AnthonyQ - the FlightRadar24 source is hundreds of ground-based (probably close on 100% home-based) ADS-B receivers like the SBS or AirNav RadarBox.
FlightRadar24 have a page on how to contribute to the data feed.
And to chip in on earlier discussion of aircraft flight ID - my understanding (my a/c only has Mode C, but I have owned an SBS since 2008) is that all Mode S transponders have the ability for pilot setting of the flight ID.
This allows operators with an AOC/issued callsign to enter the flight number into the transponder for each flight. For non-AOC/issued callsign operators, the aircraft registration, with no spaces or punctuation, should be entered as the Flight ID. In some jurisdictions the installer is supposed to set the a/c registration and then inhibit pilot selection of any other flight ID.
Some transponders, including the Garmin GTX330, can be set to automatically provide an N-reg tail number from the 24-bit/hex code. This only works for N-reg - the reasons for this have already been discussed in this thread. That alone probably explains why N-reg aircraft are better at providing their correct registration to other Mode S observers.
Flightradar24.com reports call sign, registration, mode S ID, heading, altitude, speed, transponder code, position.....along with departure airport, destination, planned track (from their flight plan I assume).....where do they get their real-time data from? (Real-time for all except aircraft in US airspace where it is delayed by 15mins I think)
I think this is a merge of a number of different data sources -
For some (many?) registries the mapping is a simple algorithm. For others it has to be looked up. Does anyone know of a centralised database for these lookups (other than the spotter sites)?
Flightradar24.com reports call sign, registration, mode S ID, heading, altitude, speed, transponder code, position.....along with departure airport, destination, planned track (from their flight plan I assume).....where do they get their real-time data from? (Real-time for all except aircraft in US airspace where it is delayed by 15mins I think)
HB reg tail numbers can also be algorithmically determined from the transponder address and vice versa.
Tail numbers in the form HB-XYZ (where X, Y and Z are letters) result in the following address: 0x4b0000+(X-'A') * 26 * 26+(Y-'A') * 26+(Z-'A').
Tail numbers in the form HB-n (where n is a decimal number, usually 3 or 4 digits long) (these are used for gliders and motor gliders) result in the address: 0x4b0000+26 * 26 * 26-1+n
The Mode S transponder has the registration number stored in it as configuration data, In the case of the Garmin transponders, if the registration is US, it has the N number determined from the aircraft address or visa versa by the algorithm, whichever value is entered first, the other is calculated. If the aircraft is used commercially, a configuration is set to permit the pilot to enter a flight ID on a per flight basis instead of the registration number. The flight ID field is 8 alpha characters and is either set to the stored registration number or the value entered by the pilot if it is configured to be entered and is entered.