warm up GPS on N95

[SteveBull]

On a cold start, I have not been able to get immediate GPS coordinates
when I launch my widget on my N95. A cold start means:
- Turning on phone and immediately launching WHERE and accessing my
widget, or
- leaving phone on for hours and launching WHERE and accessing my
widget, and
- repeated pressing of "Retry with GPS" on WHERE drop down menu

On a warm start, I have launched Widget w/ GPS. A warm start means
- Start N95 GPS receiver
- - Menu > Tools > GPS data > Position
- - sometimes it takes minutes to get GPS fix in Manhattan
- - on edge of town I get 140 degrees of sky
- - with several satellites showing empty barsin "Satellite status"
- Once I've got a GPS position (this morning accuracy reported 147m)
- then I back-n-exit out of GPS data, and
- launch my widget and eureka it works

Is this warm up GPS method for N95 the one everyone else uses to
launch WHERE widgets?

How do I discover if I have the latest native GPS software on this N95
device?



- -

[mk]

Any more insight on this one?

I find similar behavior with the N95 Maps application, where it
seems I have to initialize the GPS by running Tools/GPS Data.

MK

[SteveBull]

The nice folks at Nokia Flagship Store, 57th Street upgraded my
firmware to

V 11.2.009
28-09-07
RM-160
Nokia N95 (19.01)

and now the AGPS is kicking in and reception is vastly improved in
Lower East Side, Manhattan.

Be forewarned that when Nokia upgrades firmware all phone memory stuff
is wiped, so back it up if you need it.

Steve

[SteveBull]

More: I've become stubborn about this. So sometimes I now have to go
to my sweet spot on Delancey at the foot of the Williamsburg Bridge
with ~160 degree view of the sky to get the first all WHERE.com fix.
I've been testing this. First I launch my WHERE on the corner of
Ludlow and Grand surrounded by 5 story buildings and walk 5 minutes
through the open air street lot public garage near the F train,
pushing the "Retry with GPS" every minute, and finally when I get to
this sweet spot the N95 WHERE only GPS works. Then I can wander all
over, and most of the time get results--I'm still testing. Sometimes I
think the device repeats a reports the last fix when it can not get a
decent new one. However, If I go directly to my sweet spot (I should
warchalk these sweet spots, there's only a few of them around me her
in LES;-), I can cold start WHERE with one try. I recommend you try an
all WHERE Maine cold start within site of one tower (not too close)
and see if you can force WHERE to do it alone. Also in he back of
mind, doesn't atmospheric humidity and cloud cover effect reception?
- Steve

[Markus Wuersch]

On Mar 6, 2008, at 10:16 PM, SteveBull wrote:
> Also in he back of
> mind, doesn't atmospheric humidity and cloud cover effect reception?

GPS reception is a tricksy beast, especially in urban areas with
multipath etc., but it is not affected by rain or cloud cover. The
GPS frequency was chosen specifically so that it is not affected by
rain, etc.. At least not that you'd notice without any fancy
instruments.

Remember that GPS satellites are not geostationary and reception at
your 'sweet spots' might be good in the morning but bad in the
afternoon.

If you feel like learning more about GPS reception at a specific spot
and time, check out Trimble's free planning software: http://www.trimble.com/planningsoftware.shtml
You can specify a location and time and see the satellites you can
expect to be in view.

Cheers,
Markus

[mk]

> So sometimes I now have to go to my sweet spot on Delancey at the foot of the Williamsburg Bridge

I don't think we'll really have closure until you do the "counter
test." Head back up Delancey and take a right on Ludlow. When you
reach Houston, you should still see a fairly strong signal, and a
doorway to your left. Try walking through the door and straight ahead
to the counter and order me a corned beef sandwich. If this doesn't
work, there's also an "appetizer test" you can try a little further
west on Houston.

Anyway, now that I've got AGPS enabled, I don't seem to need to run
GPS Data in order to get a fix anymore.

MK