*Possible* improvement to GPS Fix

[dew.man]

The Vogue, in it's current hacked form, does not use aGPS.

You can completely delete that whole key out of the registry, and still get instant fixes - it wont make a bit of difference.

For a "geek" community, there are way too many people here that don't understand the difference between a cold/warm boot...

[realmeister]

Originally Posted by grooves12

Well, I made that change and didn't notice much difference. Still took several minutes to lock in on position.

Made the change listed in this thread: http://forum.ppcgeeks.com/showthread...=agps+registry

.... and now I am able to consistently get a lock in under 10 seconds, even after a bettery pull. It could be a combination of both changes, or could just be placebo effect and some kind of caching of last position that the phone is doing, but either way. I now get quick locks and am a happy camper.

WOW, I now get an almost immediate lock on some satellites, although it still takes a while to fix my position (inside a concrete building, though). Prior to this registry edit I was not able to even get one satellite fix.

[mswlogo]

Originally Posted by dew.man

The Vogue, in it's current hacked form, does not use aGPS.

You can completely delete that whole key out of the registry, and still get instant fixes - it wont make a bit of difference.

For a "geek" community, there are way too many people here that don't understand the difference between a cold/warm boot...

I wasn't so sure assist was working either.

After loading the newest Titan Radio ROM and learning a bit more (see sticky). The Touch is definitely using the "assist". You can tell when using Google Maps (NOT using COM port) that you get a rough position with NO sats first. This happens when Google Maps says "GPS Active (0)" and you see a blue dot and it starts to load maps all while still saying 0 Sats.

Your right about the params may or may not be effective and yes it will work with out them. I'm using the orginal IP and Port and Assist is working. I'll try disabling/deleting these params and see if I can get Google Maps to show it has an Assist position. It's hard to switch back to assisted mode once the Sats are cached.

[dew.man]

Originally Posted by mswlogo

After loading the newest Titan Radio ROM and learning a bit more (see sticky). The Touch is definitely using the "assist". You can tell when using Google Maps (NOT using COM port) that you get a rough position with NO sats first. This happens when Google Maps says "GPS Active (0)" and you see a blue dot and it starts to load maps all while still saying 0 Sats.

If you use an app that shows satelite info (like GPStest or VisualGPSce), you will see that the gps does indeed start "guessing" at the location before it gets a fix. I believe Google interprets these results before lock, and thus leads you to believe that you are getting aGPS.

You can further verify this with the test apps by turning the radio off before running them - you will still get an approximation eventhough there is no connection to the towers.

[realmeister]

Originally Posted by dew.man

If you use an app that shows satelite info (like GPStest or VisualGPSce), you will see that the gps does indeed start "guessing" at the location before it gets a fix. I believe Google interprets these results before lock, and thus leads you to believe that you are getting aGPS.

You can further verify this with the test apps by turning the radio off before running them - you will still get an approximation eventhough there is no connection to the towers.

I don't know. I just turned on Google Maps and the first position it showed me was actually right in fron of the local Sprint tower... After about 30 seconds it showed my real position in front of my building...

[firefly4321]

Originally Posted by dew.man

The Vogue, in it's current hacked form, does not use aGPS.

You can completely delete that whole key out of the registry, and still get instant fixes - it wont make a bit of difference.

For a "geek" community, there are way too many people here that don't understand the difference between a cold/warm boot...

I agree, the touch however can be tweak to use AGPS through a program call quick GPS that's how the Kaiser does it too. What it does it goes out and download the Ephemeris data ahead of time so you can skip the cold start all together and it does work pretty good.

[SprintTouch08]

Originally Posted by dew.man

You can further verify this with the test apps by turning the radio off before running them - you will still get an approximation eventhough there is no connection to the towers.

that makes no sense what so ever. ASSISTED gps means its using data (an IP address evident in the registry) so why would you turn off the radio? thatd leave you with ONLY gps satellites.

I do agree with the point about the warm/cold starts. And then people wonder why "omg it took 3 min for a lock!" Well thats within average for a cold start, even bluetooth SIRF III receivers take 1-2 min

"Cold Start- Time and position known to within some limits, almanac known, ephemeris unknown

Warm start- Time and position known to within some limits, almanac known, at least 3 SVs Ephemeris are known from previous operation.

The satellites (SVs) broadcast two types of data, Almanac and Ephemeris. Almanac data is course orbital parameters for all SVs. Each SV broadcasts Almanac data for ALL SVs. This Almanac data is not very precise and is considered valid for up to several months. Ephemeris data by comparison is very precise orbital and clock correction for each SV and is necessary for precise positioning. EACH SV broadcasts ONLY its own Ephemeris data. The validity of this data is dictated by the particular satellite and may be valid up to 4 to 6 hours. Each set of ephemeris data gives a "fit" indication which tells how long the particular Ephemeris data is valid. The Ephemeris data is broadcast by each SV every 30 seconds so GPS receivers have frequent opportunities to receive and log this essential information.

When the GPS is initially turned on after being off for a period, it "looks" for SVs based on where it "thinks" it is and based on the almanac and current time. With this information, appropriate SVs can be selected for initial search. When the GPS receiver initially locks onto a SV, the Garmin satellite display initially shows "hollow" signal strength bars. At this time, the Ephemeris data has yet to be completely collected (or any existing is "stale." Once the ephemeris data is collected from EACH SV in turn, the associated signal strength bar will turn "solid" black and then the data from that SV is considered valid and available for navigation."
http://gpsinformation.net/main/warmcold.htm

[dew.man]

Originally Posted by SprintTouch08

that makes no sense what so ever. ASSISTED gps means its using data (an IP address evident in the registry) so why would you turn off the radio? thatd leave you with ONLY gps satellites.

Maybe my post was confusing, but the point I was trying to make is that the ASSISTED gps does not work on the Vogue. When you get the same performance from the GPS regardless if the radio is on or not, it proves that it is NOT USING the cell tower assistance.

[dew.man]

Originally Posted by firefly4321

I agree, the touch however can be tweak to use AGPS through a program call quick GPS that's how the Kaiser does it too. What it does it goes out and download the Ephemeris data ahead of time so you can skip the cold start all together and it does work pretty good.

QuickGPS does not work on the Vogue. While it does indeed download the data, the radio does nothing with this data. Users reporting 2 second locks are simply warm-booting and demonstrating placebo...

[dew.man]

Originally Posted by realmeister

I don't know. I just turned on Google Maps and the first position it showed me was actually right in fron of the local Sprint tower... After about 30 seconds it showed my real position in front of my building...

In my experience, upon opening GMaps, it will either show the last place I used gps, or 0/0 (Africa) until it starts approximating and/or gets a fix.