> On Wed, 10 Sep 2008 16:01:32 +1000, "RT" nowhere.com.au>
> wrote:

>>That really is a fascinating idea - sort of poor man's differential
>>GPS.....

>
> Yes, that order of precision and accuracy for navigation.
>

>>If you kept track of the average position by the GPS and the difference
>>from
>>there to the inertial position, you'd be able calculate the inertial drift
>>and thence correct the GPS to inertial accuracy :-)

>
> That's about it. I thought it was used from scratch for aircraft
> systems with combined INS and GPS - the cost of the filter is a
> fraction of the cost of the system, particularly if their is already
> room available on the computing side of things to do it. Its
> certainly done with the PPS and SPS on military systems.
>
> However, on reflection, there are probably many aircraft where GPS has
> been added to an existing inertial based system and the integration
> only goes so far as to allow a position update to correct drift.
>

>>Many thanks - I'll have a prowl...tho me and Matlab never really got
>>on....

>
> Me two...