"R. Mark Clayton" <nospamclayton@[EMAIL PROTECTED]
> wrote in message
news:bNqdnUnFeZlbIIHVRVnyvgA@[EMAIL PROTECTED]
>
> "Jeff Strickland" <crwlr@[EMAIL PROTECTED]
> wrote in message
> news:1w2Tj.14223$Bb3.13032@[EMAIL PROTECTED]
>>
>> "R. Mark Clayton" <nospamclayton@[EMAIL PROTECTED]
> wrote in message
>> news:Xu-dnUHILcqPtoHVnZ2dneKdnZydnZ2d@[EMAIL PROTECTED]
>>>
>>> "Ivan Marsh" <annoyed@[EMAIL PROTECTED]
> wrote in message
>>> news:pan.2008.05.02.18.18.04.176524@[EMAIL PROTECTED]
>>>> Hey,
>>>>
>>>> When I start my car the GPS system turns on and displays the accept
>>>> agreement message.
>>>>
>>>> Is there any way to keep the GPS turned off until I need it?
>>>>
>>>> --
>>>> "Remain calm, we're here to protect you!"
>>>>
>>>
>>> In order to work a GPS receiver has acquire a first fix. There are
>>> three ways of doing this: -
>>>
>>> Permananently on - Receiver stays on all the time.
>>> Warm start - receiver remembers previous position from last use and
uses
>>> this to update its position (and the time).
>>> Cold Start - receiver makes no (or few) assumptions about its position
>>> and sets about acquiring position etc. from scratch - this can take
from
>>> several minutes to nearly an hour. This is a feature of the Navstar
>>> system.
>>
>> Are you sure about it taking so long to find itself? I sold GPS fleet
>> management systems that could find themselves in a matter of a couple
of
>> minutes. My handheld Garmin would come up in about 90 seconds.
>>
>> I've never heard of a GPS receiver taking an hour, or more than about 5
>> minutes for that matter, to figure out where it was.
>
> Things have improved especially since
>
> http://www.ngs.noaa.gov/FGCS/info/sans_SA/docs/statement.html
>
>
>>
>> But, the question the OP asked is about turning the system off until he
>> wants it on. Currently it turns on when the ignition is on, and he does
>> not want that.
>>
>>
> Well I am sure this can be arranged as long as he doesn't mind
inaccuracy
> until it is all synched up - more likely it just a question of what the
> default display is. On my BMW I would prefer if the default was current
> position...
>
I prefer this as well, but only when I decide to turn my GPS on. I live
two
miles from the interstate, so when I want GPS, it is up to speed by the
time
I reach the on ramp. It's one thing for the receiver to keep track of
itself, and another to show it on the display. It makes sense to me that
powering the display would be a separate menu item from powering the
receiver. Surely the car would not care about keeping the receiver hot all
of the time, but the OP is complaining about the display -- he does not
want
to acknowledge the end user license everytime he starts his car, and if
the
display was off, this would not be a requirement.
I did a demo of my GPS system to an armored car company in Los Angeles
once,
and my units would get momentarily lost in the jungle of the downtown
area,
but would recover in a matter of seconds. I had a laptop connected to my
unit, and drove on the same streets as the armored cars. I took the client
to the loading docks that his trucks would use, and my stuff got lost for
a
few seconds at a time in some of the alleys, but seldom got lost on the
streets. I had far more trouble with the cell towers than with the GPS
equipment. My stuff held an open connection to the cellular network, and
would dump data on a regular schedule. My trouble was that the cell link
would go away, and the GPS data would buffer and transmit when the link
came
back. Depending on how long the cell connection was lost, the GPS data
would
be retarded. The problem with this was that the dispatcher was getting
data
on the location of the truck that was outdated by several minutes. The GPS
data was always accurate, but it was delivered too late to be useful.
My equipment could keep track of the location of my car when it was in my
garage. It would get lost in the garage on occasion, and then plot the car
somewhere near Guam, but most of the time it kept track of my car very
well.
I could get a fix within seconds of powering the unit, so I have to wonder
at the accuracy of your statement that it can take up to an hour.
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