Working in Vehicle Navigation I would have to agree with these thoughts.
Replicating the GPS signal indoors is easy enough with the use of GPS repeaters,
but again the size of the store would need to be taken into account.  As for
general accuracy, even with combined Gyro and Speed and directional inputs (in
conjunction with GPS)  to calculate the vehicle position, there is still a
substantial variation in positional accuracy.  The final point is
cost......would a supermarket chain pay £300 on top of the current cost of a
trolley.

--
Peter J. McLaughlin
TO-54 -  Module 22, 23, 28
BMW Plant Oxford
Tel: +44 (0)1865 8 24545
Fax: +44 (0)1865 8 26106
e-mail: [log in to unmask]

[log in to unmask] wrote:

> At first sight, the guided shopping trolley looks as though it could be
> useful. Further thoughts question the suitability for an indoor application
> where GPS reception will be a major issue. It might do better in a large
> outdoor market, but the news item does not suggest that.
>
> The second problem in a typical supermarket, even if you overcome the
> problem of reception somehow, would be accuracy.   3 - 10 metres in open
> country or on water is often quite adequate. Road vehicles need inertial or
> other supplementary guidance, to know which side of the carriageway or
> turning they are on, but you could easily be 2 aisles away from your product
> in a store. Even when you are in the correct aisle, searching up to 30 feet
> of shelves would be a pain.
>
> Surely GPS is superfluous here. If the store system provides a lookup for
> the product and knows the shelf location, a much simpler guidance method
> could be implemented in-store. Either just a readout of the shelf number,
> together with a logical store layout to enable the shopper to find the
> shelf, or a local position-sensing installation. How about mounting
> transmitters at intervals over each aisle giving an infra-red 'footprint'
> carrying a zone code. This code could then drive the guidance arrows.
>
> I am sure there are even better ways to do it. Any ideas?
>
> Regards
>
> Martin Quaintance
> LightMaster Software
>
> Tel: +44 (0)20 8405 8200
> Fax: +44 (0)20 8405 8300
> [log in to unmask]
>
> 18 Stanley Gardens
> South Croydon
> Surrey
> CR2  9AH
> United Kingdom
>
> ----- Original Message -----
> From: "Yung Leung (Samuel)" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: 30 April 2003 10:03
> Subject: GPS to help confusing shoppers
>
> > Check this out, no more will ever get lost with a GPS-aided shopping
> > trolley:
> >
> >
> > Frustrated shoppers turn to GPS
> > LONDON (Reuters) - Frustrated shoppers who spend hours searching for an
> > elusive item are to be given help -- in the form of a satellite-guided
> > shopping trolley. Product designer Murray Laidlaw has invented the
> > trolley, fitted with a global positioning system (GPS), to guide
> > shoppers to their products, the Daily Mail newspaper said on Wednesday.
> > The device, which will sit on the trolley handle, will also suggest
> > recipes, advise on special offers and work out the quickest route around
> > the store. "Lots of people just don't shop in a methodical manner," the
> > paper quoted Laidlaw as saying. "This device will make shopping trips
> > less confusing and time consuming." GPS, initially designed for the U.S.
> > military, will guide shoppers by showing arrows on a screen which take
> > them to the correct shelf. Laidlaw has been given a 30,000 pound
> > government grant to develop the trolley and hopes to have a prototype
> > within six months.
> >
> >  (extracted from Teletext news)
> >
> > Samuel Leung, 30 Apr 2003
> >