Eric Greenwell skrev den Tue, 03 Feb 2004
12:15:57 -0800:
It's my understanding that the conflict resolution algorithm is based on
much more realistic assumptions, so that climbing and turning flight of
the potential threats is included. The simple assumption of straight
flight might have been used in the very beginning, but no longer. If you
have a recent reference that suggests otherwise, I'd like to know about
it.

The algorithm is to look at a number of consecutive returns to determine a
rate of closure and then divide the distance with this rate to give a
'tau' value, of time to impact should there be a collision. When this
value goes below an [altitude dependant] threshold, you have a traffic
advisory. Another lower [also altitude dependant] threshold, and the TCAS
begins working on a resolution advisory.

In other words, more or less straight but not level flight is assumed.

Cheers,
Fred