GPS with IRS

djkriz · 08-05-2004, 05:03 AM

Does anybody know if there exists an usb GPS unit with built in IRS (gyro), so it keeps a fix even in places without sky-view (like a tunnel)

I know the new tom-tom GO unit has a built in gps like that, but is it available stand-alone?

BartGoesCarPC · 08-09-2004, 08:18 AM

Now that was an interresting quest

The query to

for is "dead reckoning" (DR)

I found that the gyroscopic technology is mostly used on boats, to know the heading of the ship. Speed on boats is usually to slow to know heading from GPS data.

For car purposes a few navigation kits have a gyroscope included for DR. (Garmin SP2650 / 2660 and TomTom GO).
A single GPS mouse with DR for (Pocket) PC purposes does not seem available.

BUT, there's Trimble. They make nice stuff. Their "Placer GPS455DR" supports DR for "...use in difficult urban environments...". But when you look at either the specs or the device itself, you wonder if this is what you're looking for. Three (?!) RS232 ports.

There are not a lot of shops selling these baby's, but here's one for sale at the price of $1100! Woohaa

Trimble has some very interresting reads about the GPS & Dead Reckoning (in the 455DR unit), and about GPS itself.

I guess we'll have to wait a little to get this in our cars....

rando · 08-09-2004, 10:47 AM

Then again, you could might just buy an inexpensive gyro or digital compass and tap the speed sensor in your car (assuming your car has one ... most newer cars do). Add to this a cheap GPS unit and you have all that you need to to navigation with dead reckoning. You'll still need to roll your own code though.