There actually was a pretty big error...the technique used by Raytheon to
flag bad data was different then the one the bridge system was using to
respond to bad data. In my view as an electronic systems guy that was a very
big error...particularly in a system that could lead to a people/property
hazard.

I agree though that it should not have been so significant because there
were multiple other ways to catch it in this case. But I could postulate
cases where it could be quite serious quite quick.

In the heavy boat business I would have thought two or three GPS receivers
would be standard aside from any additions like LORAN. Three is a little
magic because it almost always allows you to isolate the mis-behaving unit.

I don't think you can integrate radar into such a system. You can show the
picture or the picture enhanced but the software to match a view to a map
would be very difficult. If however you know where you are (or think you
do) it is possible that you might match the patterns. Cross check
perhaps...but quite sophisticated software.

Of course your people can cross check radar and fathometer. If you can keep
them focused to do so. A known hard problem.

Jim

"otnmbrd" wrote in message
ink.net...
Jim Donohue wrote:
So we actually agree? The system was seriously flawed but the Crew
should have caught it anyway as there were multiple and pretty obvious
indications that competent sailors should have caught.

Jim

G To a point. I don't think the system was "seriously" flawed, since SOP
and good training should have caught it, with the system as is/was.
I tend to use "competent" in a stricter sense .... they may well have been
competent mariners, but they sure screwed up.
If I have a beef, it would be (as expected) with simply doubling up on
GPS, especially on approaching Nantucket. Although a 2nd GPS would be nice
(and generally standard), I would still prefer that double checks would
involve different systems..... Radar, Loran, Fathometer, Visual..... when
available.

otn