OT: Re: Looking For Geodetic Python Software

[Diez B. Roggisch]

> 	The article implied that the automated system would allow for
> /shorter paths/ (the shortest path is the great circle, so this
> statement indicates that trans-oceanic flights are not using great
> circle/GPS routing). Most likely, the flights are using 50 minute "plumb
> lines", with a heading change at the 50 minute mark, so current position
> and new heading can be reported to ATC. GPS may be supplying the pilots
> with position info, but they may not be free to make the constant
> heading changes... The automated system may send this information
> digitally at much higher rate than 50 minutes, allowing ATC to plot near
> realtime positions.

Looks as if I stand corrected - I remember clearly when we were 
introduced to great circles in school, that the example given were 
intercontinental flights. So it appears that they use a discretization 
scheme that our teacher embezzled. Terry Pratchett calls that "Lies for 
kids".

On further thinking, it makes sense that it's not allowed to constantly 
change heading - it makes the course estimation for e.g. approaching 
aircrafts complicated.

Thanks for pointing that out!


Diez