Sign In Join 



2008 Subaru Impreza WRX

1480 messages,  Last post on Jul 06, 2009 at 4:52 PM

You are in the Future Vehicles Forum. Your Host is kirstie_h

What is this discussion about? Subaru Impreza WRX STi, Subaru Impreza, Future Vehicle, Sedan


Messages Page 92 of 149
1
...
89
90
91
92
93
94
95
...
149
Prev
Next
Last
Go To Msg #
Search This Discussion

#903 of 1480
Re: 2008 WRX Pricing Questions [ateixeira] by rsholland
Sep 19, 2007 (7:54 am)
Reply

Replying to: ateixeira (Sep 19, 2007 7:39 am)

But are tunnels the only place you might lose a signal? What if the satellite(s) are not in range for some reason? For example, I notice that from time-to-time I will lose an iTunes radio station on my MAC, and I have to switch stations in order to hear music. Can that happen with a GPS? Could it happen where you might have road choices open to you?
 
Bob
#904 of 1480
Re: 2008 WRX Pricing Questions [rsholland] by ateixeira
Sep 19, 2007 (8:03 am)
Reply

Replying to: rsholland (Sep 19, 2007 7:54 am)

You get a weak signal if you are surrounded by high-rise buildings, but my Garmin can usually compensate.
 
I have an older model. It can take a little while to obtain the signal the first time. I don't have a problem with losing a signal once I get going though.
 
Besides a tunnel, I also lose signal in a covered garage, but again, I'm not relying on the GPS at that time.
#905 of 1480
Re: 2008 WRX Pricing Questions [ateixeira] by xyzzer
Sep 19, 2007 (8:20 am)
Reply

Replying to: ateixeira (Sep 19, 2007 8:03 am)

The manual states:
 
"Self-contained navigation is a system that detects the vehicle's position by calculating the vehicle's driven distance and turning angle th(r)ough the use of various types of sensors that are mounted on the vehicle."
 
So the direction is detected by driving with the wheels turned as well and it works in the underground parking lots!
 
Of course not that you would need that, but there are underground parking lots where you could get lost and as people stated - you can lose the signal anywhere. If not for these anyway the positioning would not be so detailed and smooth - the GPS I have with my MapPoint tends to teleport me from place to place where the visibility is limited giving the annoying "off route" warnings...
 
I wonder what would it look like if I started drifting in that underground parking...
#906 of 1480
Re: 2008 WRX Pricing Questions [xyzzer] by jeffmc
Sep 19, 2007 (8:53 am)
Reply

Replying to: xyzzer (Sep 18, 2007 11:06 pm)

A Zune user on the Eastside? What're the odds of that?!
 
Hey, thanks for posting up your answers... good to read you're so satisfied w/your new WRX. From your videos, it looks like you had a lot of fun w/your Outback Sport, so this should be a real blast.
#907 of 1480
Re: 2008 WRX Pricing Questions [xyzzer] by ateixeira
Sep 19, 2007 (10:02 am)
Reply

Replying to: xyzzer (Sep 19, 2007 8:20 am)

Drifting would probably make the GPS go nuts!
#908 of 1480
Re: 2008 WRX Pricing Questions [ateixeira] by paisan
Sep 19, 2007 (6:06 pm)
Reply

Replying to: ateixeira (Sep 19, 2007 10:02 am)

Here in NYC they have GPS Transponders in the tunnels. My Garmin only loses signal for me when travelling on the lower level of our bridges. I dunno what sky scrapers would block the signal, as I live in NYC and never have a problem with signal. The "Gyroscopic" sensors in the built in units are cool but not necessary IMHO.
 
-mike
#909 of 1480
Re: 2008 WRX Pricing Questions [paisan] by jeffmc
Sep 19, 2007 (6:55 pm)
Reply

Replying to: paisan (Sep 19, 2007 6:06 pm)

In addition to canyons, steep valleys, and high-rise environments, perhaps in more northern latitudes it's harder to keep contact w/the satellites since they're lower on the southern horizon and therefore more easily blocked. Dunno, but that's my guess. I'm assuming the heaviest satellite coverage is over the heaviest population areas, and I've read that coverage ranges from 8 satellites in continuous line of sight in some latitudal zones, to 5 in others. You need 4 satellites for accurate GPS tracking, so in some zones there's not as much backup coverage if something's blocking line of sight.
#910 of 1480
Re: 2008 WRX Pricing Questions [rsholland] by lilengineerboy
Sep 20, 2007 (6:26 am)
Reply

Replying to: rsholland (Sep 19, 2007 7:28 am)

The navigation is pretty cool. Actually even with no satellites in sight it seems to manage by just checking the speed and direction.
  
How can it work without a satellite?
 
The term is dead reckoning, and it uses your last known position and the sensors mentioned (speed, heading, pitch/yaw or steering wheel angle) to determine position.
The algorithm is designed to switch back and forth as it needs to - satellites are preferred but dead reckoning can work intermittently as necessary as well.
Its pretty amazing how far these have come. When we were doing interface evaluation on the Magellan 750 Nav (better known as "Hertz Neverlost" there were limited connections to vehicle information.
Now some handheld models include position sensors for dead reckoning: Garmin StreetPilot 7500
#911 of 1480
Re: 2008 WRX Pricing Questions [paisan] by ateixeira
Sep 20, 2007 (7:05 am)
Reply

Replying to: paisan (Sep 19, 2007 6:06 pm)

That's cool, mike.
 
I have the older C series models, the newer ones have SIRF technology and quicker/better reception. I'm sure that helps.
 
It's never really been a problem, just some times it can take a minute to establish the original signal when I power it on.
#912 of 1480
Re: 2008 WRX Pricing Questions [rsholland] by aaykay
Sep 20, 2007 (9:14 am)
Reply

Replying to: rsholland (Sep 19, 2007 7:36 am)

Yes, that is true of all the built-in OEM units. That is because the NAV is integrated into the car's controls and thus has "Dead Reckoning". It records the last obtained satellite signal, then in the absence of signal, will estimate your position based on the direction/speed/altitude of the car, until it obtains the next signal.
 
The Garmin type systems (I have a Garmin 660 with the newer Sirf Star III chip) does not do as well in such situations. My point of comparison is with my Garmin and my Honda Odyssey's built-in NAV. Garmin does have a model with dead reckoning (one of their 7-series model ??) but then that has to be professionally installed into the car's controls and I assume you lose some of the portability.

Messages Page 92 of 149
1
...
89
90
91
92
93
94
95
...
149
Prev
Next
Last
Go To Msg #
Search This Discussion
To POST a message, please Sign In.

New? Join Now!

Forum Tools

Please sign in.
Email Address:

Password:

Forgot Password?

Search Forums

Enter Keyword(s)

Advanced Search

Browse by Vehicle



View All Vehicles
Advertisement
Ask the Community
See What People Are Asking

Browse by Board

Browse by Topic


View All Topics

Today's Chats

Advertisement