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   Re: Request Comments: iPhone GPS Performance Compa...
| Wolfgang S. Rup... | 05-11-2010 |
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On May 11, 1:29=A0pm, wolfgang.rupprecht+gnus201...@gmail.com (Wolfgang
S. Rupprecht) wrote:
> I tend to use both a cell (HTC G1 "google" not iphone) and a Garmin
> 60CSx a the same time. =A0(Hey my backpack has two straps, I have to put
> something on each don't I, lest I loose my nerd ID-card?) =A0The two GPS'=
s
> 60CSx a the same time. =A0(Hey my backpack has two straps, I have to put
> something on each don't I, lest I loose my nerd ID-card?) =A0The two GPS'=
> tend to have different abilities that nicely compliment each other. =A0In
> the car where external power is available, the cell phone is the GPS of
> first choice. =A0It is only in the boonies that I fall back to the Garmin=
.
> the car where external power is available, the cell phone is the GPS of
> first choice. =A0It is only in the boonies that I fall back to the Garmin=
> The cell has fresher maps, has most area businesses shown on high zooms
> and as far as I can tell, actually "learns" (or gets manually corrected
> ???) after overriding the GPS's instructions a number of times.
> My cell phone (and all the one's I've seen) seem to have pretty weak,
> power hungry GPS's. =A03 hours is all I get on a full charge with the GPS
> nailed on. =A0Getting a car cell-phone power adaptor is the key to
> happiness. =A0Ditto for a large roll of sticky-backed velcro.
> The EPE on the cell gps is often many times worse than the Garmin and it
> is much lower to lock and to drift to the correct position. =A0It looks
> like the cell gps is very heavily post-filtered from how long it takes
> it to drift to the new position after quickly moving from one spot to
> one 50ft away. =A0On the other hand, the Garmin seems to track without an=
y
> and as far as I can tell, actually "learns" (or gets manually corrected
> ???) after overriding the GPS's instructions a number of times.
> My cell phone (and all the one's I've seen) seem to have pretty weak,
> power hungry GPS's. =A03 hours is all I get on a full charge with the GPS
> nailed on. =A0Getting a car cell-phone power adaptor is the key to
> happiness. =A0Ditto for a large roll of sticky-backed velcro.
> The EPE on the cell gps is often many times worse than the Garmin and it
> is much lower to lock and to drift to the correct position. =A0It looks
> like the cell gps is very heavily post-filtered from how long it takes
> it to drift to the new position after quickly moving from one spot to
> one 50ft away. =A0On the other hand, the Garmin seems to track without an=
> visible lag.
> The real advantage of the cell is that you get to share your position
> (and geotagged pictures!) in near real-time with friends. =A0You can send
> people a "come meet me" email message with pictures, upload your
> tracklog etc, all from the trail. =A0The no hassles tracklog sharing via
> Google's "mymaps" is so easy I don't even bother uploading the tracks
> from my Garmin any more. =A0It is a real kick to see one's tracklog
> supperimposed on the Google overhead imagery (misnamed "satellite").
> Highly recommended.
> -wolfgang
> The real advantage of the cell is that you get to share your position
> (and geotagged pictures!) in near real-time with friends. =A0You can send
> people a "come meet me" email message with pictures, upload your
> tracklog etc, all from the trail. =A0The no hassles tracklog sharing via
> Google's "mymaps" is so easy I don't even bother uploading the tracks
> from my Garmin any more. =A0It is a real kick to see one's tracklog
> supperimposed on the Google overhead imagery (misnamed "satellite").
> Highly recommended.
> -wolfgang
Yeah, I've done the google "satellite" while driving via my
blackberry. It is entertaining, though I've also done this with
expertgps and the old B&W USGS imagery. I will use the google maps or
blackberry maps if I'm on foot and lost in a city. I find getting out
of subways to be great for losing your orientation.
If you turn off the GPS, google can indicate your position via E911
(I'm guessing) technology. Often under 100ft!
An interesting program, though only for blackberry, is
http://f5bbutils.fairview5.com/signalloc/
It uses the GPS in the phone and a database (if GSM) or the tower
position (CDMA) to compute the distance and direction to the cell
tower you are using. I suspect the program exists for other platforms
since the phone has all this information internally. It yields geeky
information about the cell site.
CDMA apparently reports lat/lon of the towers. GSM doesnt, and depends
on a rather crappy database from Google that is wrong more often than
it is right.
Some info on the GPS chipsets in the iPhone and iPad:
http://www.iphonehacks.com/2010/05/ipad-3g-teardown-reveals-innovative-lcd-frame-as-an-antenna-improved-gps-processor.html
"The iPhone 3G model comes with 3 additional antennas to help with GPS
and 3G connectivity. The black RF Window on top of the iPad houses two
of these antennas, one each to assist with reception of 3G and GPS
signals. A third antenna is attached to the LCD frame, which ensures
better cell reception. iFixit notes that the entire LCD frame is built
to be used as an antenna."
"As we had noted in our article comparing the GPS capabilities of iPad
3G and iPhone 3GS, the superior performance of GPS on iPad 3G is due
to the presence of the Broadcom
BCM4750UBG Single-Chip AGPS Solution. In contrast, the iPhone 3GS is
equipped with an Infineon Hammerhead II package."
http://www.iphonehacks.com/2010/05/ipad-3g-vs-iphone-3gs-3g-speed-gps-improvements.html
"Gizmodo's study points to an interesting observation with respect to
GPS functionality on iPad 3G. The study notes that the iPad takes
marginally more time to pull a final GPS lock as compared to iPhone
3GS. However, the lock on iPad was stronger and its GPS was observed
to be much more accurate compared to GPS measurements on iPhone 3GS."
http://www.ifixit.com/Teardown/iPhone-3G-Teardown/600/1
http://www.ifixit.com/Teardown/iPhone-3G-Teardown/600/3
"The GPS chip is the grey chip in the middle-right side of the board.
It is an Infineon PBM2525 Hammerhead II! Rumors that it would be
integrated into the processor have been disproved"
wrote:
>Request Comments: iPhone GPS Performance Compared to dedicated
>GPS receiver of comparable price.
>I'm interested in user experiences with the iPhone GPS
>compared to dedicated GPS Receivers.
>Thanks
>-Sam
>GPS receiver of comparable price.
>I'm interested in user experiences with the iPhone GPS
>compared to dedicated GPS Receivers.
>Thanks
>-Sam
It's pretty poor, there are side by side comparisons here
http://www.gpspassion.com/fr/articles.asp?id=275 between the built-in
module and the TomTom Car Kit receiver, essentially a dedidated GPS
receiver.
- A Multimedia Community for GPS Users
- Garmin GPS
- 2008-12-09
- Garmin Navigator v7 Request
- Garmin GPS
- 2006-01-17
- GPS Drop in Price
- Global Positioning System
- 2005-12-29
> > activated? If so, that would make an iphone cost about $720 US per
> > year, i.e. the cost of voice and data.
> > You would have to be insane to depend on the GPS of a phone, at least
> > in the boonies. Most have maps that are downloaded, and you may not
> > have coverage. Then there is the issue of batteries. No phone takes AA
> > cells (though many can use emergency AA cell power supplies).
> > A real GPS rules. I had the opportunity to compare the iphone nav to
> > my car nav (whatever Nissan uses). The iphone had issues with the map
> > when the signal was lost, and in the states, you always lose that AT&T
> > signal.