I agree. The signal would have been lost. I'm curious, though about
the sensors you mention. My handheld simply extrapolates when it
experiences signal loss, ie, continues in the same direction at the
same speed. After some predetermined time, it goes into a holding
pattern and reports the lost signal. Obviously an auto-based system
*could* have a speed sensor, but I'm surprised if it does. Calculating
speed from the GPS readings should be much more accurate than the
speed sensor in the car and it provides a vector speed (direction and
ground speed).

I'm not saying you're wrong. I'm just curious about the source of your
information about the navigation system having a gyroscope and speed
sensor. I've never heard that before.

Tom


On Thu, 24 Jul 2003 22:55:12 -0700, Dick <rhughes33@cableone.net>
wrote:

>Obviously, the GPS signal was lost when you entered the tunnel. This
>is evidenced by the word GPS turning white from green. The navigation
>system contains gyroscopic and speed sensors to keep track of the
>direction of the car at all times. It was probably using dead
>reckoning to follow the map for the time you were in the tunnel.
>
>Dick
>
>On Fri, 25 Jul 2003 03:23:27 GMT, Milleron
><millerdot90@SPAMlessosu.edu> wrote:
>
>>On Thu, 24 Jul 2003 17:19:42 GMT, "noway" <nospam@nospam.com> wrote:
>>
>>>Moisture and especially heavy rain will effect satillite reception.
>>Probably true, but I'd like to share my experience driving through the
>>Brooklyn-Battery tunnel under the East River in New York a couple of
>>weeks ago. I was under a couple of hundred feet of water, a dozen
>>yards of dirt and rock, and a shell that was probably either solid
>>steel or five feet of rebar-inforced concrete. The Navigation System
>>tracked me every foot of the way.
>>Go figure.
>>
>>Ron
>>
>>>
>>>"Ken" <googleguy_nj@yahoo.yahoo.com> wrote in message
>>>news:MiSTa.70611$0v4.4716525@bgtnsc04-news.ops.worldnet.att.net...
>>>> Yesterday my navi was unable to correctly track my car. It was off by
>>>maybe
>>>> half a mile. After awhile it seemed to be ok.
>>>>
>>>> Yesterday there was heavy cloud cover and storms. But I didn't think this
>>>> could affect GPS reception. Any ideas? (There was nothing covering the
>>>> antenna area in the rear.)
>>>>
>>>>
>>>
>>
>>Ron