Βρήκα αυτό. . .
Q0 messages "reports" to the server under witch specific Ground Link coverage the aircraft located.
Highlight here that each aircraft has its unique address. That is the registration mark.
That works with a calculation of Ground Link station signal strength h from the aircraft.
That is happens because an aircraft flying at FL390 maybe receiving more than 1 GL.
ACARS messages are very structured. Each position in the message has
a specific function. The common Q0 Link Test and QG Out/Return In
Reports are shown as examples:
_ Address Field _ Message Label _ Downlink Block
Identifier
_ Q0 - LInk Test
_ Address Field Line 1 Length = 7 characters
The address field identifies the aircraft with which the ground station is
communicating. For the uplink (ground to air) messages it will be either the
aircraft's official registration mark or the flight number of the service operating
the aircraft. For downlinks (air to ground) messages it must always be the
aircraft's official registration mark. By international agreement, the official
registration marks are coded according to a county of origin one or two letter
ICAO prefix. The single letter "N" is the prefix for all American aircraft. Other
prefixes include: "C" for Canada, "G" for Great Britain, "F" for France, etc.
For ACARS purposes, the Address field must be seven characters in length
and is always right-justified. If the aircraft's identification is less than seven
characters, it must be left-filled with periods. Valid examples:
N1825TU .C-FDCA .D-ABXR
.N123UA .F-GHGF .D-ABIT
..N1901 .HB-IGC .G-BNLG
...N409 .PH-BFP .G-DOCV
_ Message Label Line 1 Length = 2 characters
ARINC has defined a series of two character message labels that identify
message type. Many airlines have also defined their own sets of labels for
company operation purposes.
_ Downlink Block Identifier Line 1 Length = 1 chars.
The DBI is used primarily as a means of indicating the retransmission of a
previously downlinked message. If the DBI suffix is present, it will always be
directly appended to the Message Label (without a space).
_ Message Sequence
Number
_ Carrier & Flight
Number
.N900UA Q01
5400 5400UA1750
Page 3
_ Message Sequence Number Line 2 Length = 4 chars.
For most downlinked messages, the Message Sequence number is a four
digit value that represents the time in minutes and seconds past the hour
that the message was transmitted. (Note that the hour is not given).
_ Carrier & Flight Number Line 2 Length = 6 chars.
The six character flight number field is comprised of a two-character airline
identity code followed by a four-character alpha-numeric flight number. If the
flight number is less than four characters in length, it will generally be rightjustified
and left-filled with zeros. Examples: AC1030 UA0038 AA0009
Scheduled carriers may also conduct charter flights. The letter F is normally
appended to the two-letter airline code to indicate that the flight is a charter.
For example, an Air Canada charter: ACF095. Business jets frequently use
the ACARS network. Since these are not scheduled commercial flights, they
do not have assigned flight numbers. The general carrier and flight number
designation for business jets is always GS0001 GS0001.
) εκπεμπουν ισως στοιχεια πτησης by default, "θεωρωντας" οτι υπαρχει δεκτης. Η εκπομπη αυτη δεν στοιχιζει τιποτε στο αεροπλανο, δεν καταναλωνει τιποτε πορους που θα μπορουσαν να αξιοποιηθουν αλλου.
!Βάλ'του να στέλνει και coordinates και άσ'το να ξεσκίζεται!Και αν θέλει το AirNav η ΑΕΕ, της το στέλνω εγώ σε CD 
