Re: How does TCAS get range and bearing?

Bob ...

I think you are a little bit off the mark.  TCAS sends, in one form or 
another, my lat/long/altitude out either as a radar blip to an
interrogation 
or from GPS coordinates.  If you know your own l/l/a and you get another 
l/l/a and the l/l/a of the interrogator, just a wee bit of geometry and 
software can give you target info accurate to a degree and a few feet of 
altitudinous.

Jim

-- 
"It is the mark of an educated mind to be able to entertain a thought 
without accepting it."
        --Aristotle


"Bob Noel" <ihatessppaamm@[EMAIL PROTECTED]
> wrote in message 
news:ihatessppaamm-D55A93.19444303062008@[EMAIL PROTECTED]
> In article <1hdz3cp9zslvq.bd6inf8tkh7s.dlg@[EMAIL PROTECTED]
>,
> Dallas <Cybnorm@[EMAIL PROTECTED]
> wrote:

> Well, it is a radar system.  It determines RAnge and Direction the same 
> way
> the ATC Beacon Radars do.  The TCAS II system sends out an
interrogation,
> times the response from the cooperating targets to get range.  Crude 
> direction
> information is determined by the 4-pole antennea.  This azimuth 
> information
> isn't  particularly accurate (on the order of +/- 15 degrees)