Re: [Opengc-devel] nav display status

[Damion S. <be...@cs...>]

Hi,

> What I seem to remember is that the best projection was the one most
> frequently used for aviation maps.

I emailed my uncle, who is an A320 pilot for US Airways, and he is not 
sure what projection is used on the Airbus ND. He did say that the 
largest range scale on the ND is 320 NM, and that at that scale, both 
great circles and lines of constant heading appear as straight lines. 
He's sending me a photocopy of the operations manual that deals with 
the ND, so maybe I'll get the question answered from the real thing...

> BTW: for conversion routines, there's the PROJ project. This might help
> you in OpenGC

Yeah, I ran across that too. Unfortunately, the code isn't really in a 
useful form (it's heavily macro'd), so I'd have to link against yet 
another library. The gnomonic projection looks like it should be pretty 
straightforward to code.

> Some time back I looked at OpenGC and what kind of
> transformation/projection you used... this seemed to be a special local
> projection from the Netherlands, if I remember correctly. I was
> wondering why you choose that one.

I didn't, actually. A while back, two guys were working on adding ND 
code, and that was their choice. I lost contact with them and decided 
to rewrite things completely so that I understood how it worked.

> My project (X11GC) can be found at:
> http://cockpit.varxec.de/software/x11gc.html
> along with my flightgear-based cockpit contruction project:
> http://cockpit.varxec.de

Looks cool... keep in touch about the nav stuff.

Cheers,
-Damion-

---------
Damion Shelton
Carnegie Mellon University, Robotics Institute
A408-o Newell Simon Hall
412.268.3866 (office)
412.818.8829 (cell)
http://www.cs.cmu.edu/~beowulf
---------
I wish I would have a real tragic love affair and get so bummed out 
that I'd just quit my job and become a bum for a few years, because I 
was thinking about doing that anyway.