Re: Inertial Navigation ???

From:         inet@intellisys.net (brian whatcott)
Date:         21 Apr 2000 10:42:43 -0700
Organization: Teleport
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In article <u0k8j6g3dt.fsf@orville.dfrc.nasa.gov>, pkearn@eircom.net says...
>.....
>Now with GPS - the NAV systems can be updated even when out in the
>Atlantic/Pacific where DME may not be available.  Which i suppose is
>''re-zeroing'' itself.

>The B737 Flight Managment Computer uses DME/DME cross-bearings to
>confirm its location when it knows that it has 2 DME's to work with.

>But... your machine wont have this luxury...

>i take it that youre talking 3-D for your own project and therefore
>counting stepper-motor pulses on a known diameter wheel to indicate
>position change from known-origin would be useless ??

Well, well. This dead reckoning suggestion of Paul's took me back a
few years to a visit I made to the Dublin Bus Company.

They adopted a very forward looking scheme in the 70's to monitor
public transport buses in their system in real time - with a radio
link at a control center with traffic displays.

Before GPS and the like were a viable choice, they were using bus
wheel counters to transmit progressive position reports with lamp post
mounted interrogators to keep the drift in bounds.

I seem to recall they had a little teething trouble with using an
array of minicomputers to process various parts of the task - before
deciding that the tasks could well be amallgamated.

Fascinating - wonder what became of it?

Brian Whatcott     Altus OK