Mode S transponder display to ATC?

"Jay Maynard" wrote in message
...
On 2008-09-05, Mike wrote:
"Jay Maynard" wrote in message
Not directly, but I got curious to see how it was assigned, and started
poking at the FAA registration database (which includes the assigned
code). The algorithm winds up assigning 50000001 to N1, 50000002 to N1A,
50000003 to N1AA, 50000004 to N1AB,... 50000032 to N1AZ, 50000033 to
N1B,
50000034 to N1BA,... 50001131 to N1ZZ, 50001132 to N10, 50001133 to
N10A,
and so on. I never got to the point of writing C code that would
generate
the code, but it would be fairly straightforward. The algorithm depends
on the rules for assigning N numbers, and works left to right, with the
letters in order from A to Z (skipping I and O), then 0-9, taking all of
the letter combinations in order before expanding the number field.
There's no need as it's already been done and put online.

http://www.airframes.org/

Well, it appears he's written the code, but it doesn't appear to be
available...I'd like to see the actual code, just to check if my thoughts
on
the programming required to go in the reverse direction are correct. I'd
also like to see if other countries assign their codes algorithmically.

The algorithm is part of the ICAO standard, so if other countries aren't
doing this, they are doing so outside the standard.

If you could find the written version of the standard in the ICAO
conventions, it would probably verify your suspicions, but ICAO standards
are a bit hard to find without paying for a copy as ICAO would like you to
do.

On 2008-09-05, Mike wrote:
The algorithm is part of the ICAO standard, so if other countries aren't
doing this, they are doing so outside the standard.

Uhm...since the US algorithm is quite dependent on the US rules for
assigning registration numbers, it would not work at all for, say, the UK.
(Although, in fairness, the UK's algorithm, as well as that for countries
that use all-alphabetic registration systems, would be quite a lot simpler
than the US one.) That either says it's not in the ICAO standard, or else
there's more than one.
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
Fairmont, MN (FRM) (Yes, that's me!)
AMD Zodiac CH601XLi N55ZC

"Jay Maynard" wrote in message
...
On 2008-09-05, Mike wrote:
The algorithm is part of the ICAO standard, so if other countries aren't
doing this, they are doing so outside the standard.

Uhm...since the US algorithm is quite dependent on the US rules for
assigning registration numbers, it would not work at all for, say, the UK.
(Although, in fairness, the UK's algorithm, as well as that for countries
that use all-alphabetic registration systems, would be quite a lot simpler
than the US one.) That either says it's not in the ICAO standard, or else
there's more than one.

I haven't read the standard, but the hard wired serial number in the ModeS
transponder is refered to as the ICAO ID. I'm also quite sure the standard
exists in the ICAO convention.

Peter writes:

The UK CAA have a public database linking Mode S codes with tail
numbers (google on G-INFO) so it would be easy enough to trace a
specific aircraft from the 24-bit ID.

Odd that such a database would be public in a country that forbids listening
to ATC.

Peter wrote:

You would however get into trouble if you recorded ATC and then openly
published the recording, e.g. on a website. I don't know why there is
this sensitivity because UK ATC are generally highly professional;

Maybe a parallel to Germany might help. In Germany, tapping into any
communication not intended by the sender to be heard/read/whatever by
oneself is illegal (regardless of whether there are measures taken to
prevent this) under privacy laws. There are some exceptions, but that's the
general rule. ATC communication is only intended for a limited circle of
recipients. Plane spotters are not the intended recipients, thus, they may
not listen.

It has nothing to do with perceived professionality of the ATC people, and
everything with protecting the privacy of ATC and pilots.

Michael Huber writes:

Maybe a parallel to Germany might help. In Germany, tapping into any
communication not intended by the sender to be heard/read/whatever by
oneself is illegal (regardless of whether there are measures taken to
prevent this) under privacy laws. There are some exceptions, but that's the
general rule. ATC communication is only intended for a limited circle of
recipients. Plane spotters are not the intended recipients, thus, they may
not listen.

If you take that to its logical conclusion, it should be illegal for pilots to
listen to any ATC transmission that isn't specifically addressed to them.

It has nothing to do with perceived professionality of the ATC people, and
everything with protecting the privacy of ATC and pilots.

I'm certain that it has nothing to do with protecting privacy, and everything
to do with protecting incompetence.

Anthony Atkielski said:
I'm certain that it has nothing to do with protecting privacy, and
everything
to do with protecting incompetence.


Finally, Anthony has found something where he has some expertise and
experience- congratulations!

Mxsmanic wrote:

If you take that to its logical conclusion, it should be illegal for
pilots to listen to any ATC transmission that isn't specifically addressed
to them.

*sigh* I'm going to violate my rule against replying to MXS and reply to
this, since I think it's an easy mistake to make. It isn't, as the ATC (and
any transmitting pilots) are fully aware that all pilots are listening in.
Thus, it is not an invasion of their privacy, since the transmitting party
is aware of these listeners. Further, it is actually beneficial and
intended for all pilots to listen, since listening to all transmissions can
enhance the pilots' situational awareness - they know what the other guy is
doing. So, the argument is that while only one plane is specifically
adressed, the intended recipients are really planes on the frequency.

Michael Huber writes:

I'm going to violate my rule against replying to MXS and reply to
this, since I think it's an easy mistake to make. It isn't, as the ATC (and
any transmitting pilots) are fully aware that all pilots are listening in.
Thus, it is not an invasion of their privacy, since the transmitting party
is aware of these listeners.

In that case, since pilots and ATC are also generally aware that people on the
ground are listening in, spotters and others listening to the communications
aren't breaking the law, either.

Further, it is actually beneficial and
intended for all pilots to listen, since listening to all transmissions can
enhance the pilots' situational awareness - they know what the other guy is
doing.

It is beneficial for people on the ground to listen in as well, as it improves
their situational awareness of the state of flights in the air.

So, the argument is that while only one plane is specifically
adressed, the intended recipients are really planes on the frequency.

So is it legal for United to have a channel on the aircraft that allows
passengers to listen to ATC? Why, or why not?

Michael Huber writes:
Peter wrote:

You would however get into trouble if you recorded ATC and then openly
published the recording, e.g. on a website. I don't know why there is
this sensitivity because UK ATC are generally highly professional;

Maybe a parallel to Germany might help. In Germany, tapping into any
communication not intended by the sender to be heard/read/whatever by
oneself is illegal (regardless of whether there are measures taken to
prevent this) under privacy laws. There are some exceptions, but that's the
general rule. ATC communication is only intended for a limited circle of
recipients. Plane spotters are not the intended recipients, thus, they may
not listen.

It has nothing to do with perceived professionality of the ATC people, and
everything with protecting the privacy of ATC and pilots.

The law in the U.S. is/was that it's illegal to intercept
/and reveal/ the content of a transmission. The courts
have repeatedly ruled that intercepting (listening to) a
transmission is not illegal.

It would seem that the German position is rather extreme
in that the people on a given aviation frequency have no
expectation of privacy (and, for the most part, couldn't
care less). Taken to an extreme, it would seem that the
German equivalent of the FAA can't record ATC transmissions
and use them for quality control, training, or violation
proceedings since uninvolved third parties will have been
recorded.