Re: HP, weight and visability

[Dave Everett <deverett@idx.com.au>]

At 10:19 AM 19-04-98 -0600, you wrote:
>
>Sure, the Vector 2XG, $99 from Precision      Navigation. It has a serial
>interface. Check out http://www.PrecisionNav.com.

> I'm      unfamiliar with the Vector 2XG. If, for example, a sub were
>spiraling      (barrel rolling) on a 45 degree angle towards the surface,
>how would the      device react? I guess if it handles pitch and role, it
>should have no      problem with this right?

You could expect large directional errors in your readings at 45deg, as the
coils can only swing 15deg from level.

>From the application notes:
"For example, in Mountain View, CA, for each 1deg of tilt, there would be
about 3deg of heading error. In Greenland, for 1deg of tilt, there can be
about 10deg of heading error"

On another note, I recall someone suggesting that dead reckoning could be
used to map the position of an autonomous underwater vehicle. The position
of the robot would be affected by currents etc. You might get fair accuracy
in a pool, but nowhere else.

Dave Everett