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JJnTJ

Do any mobile phones use WAAS/EGNOS?

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My Android phone (HTC Aria) got me into caching, but it's just not reliable enough to be my only GPSr; my Garmin 60CSx is my primary.

 

The thread about the newly activated WAAS satellite prompted me to check my mobile to see if I can pick up 51, 48 or 46. And sure enough, none of those birds appear. The display will show nearly the same constellation as my Garmin, but without a WAAS bird.

 

Neither of the "wrapper" apps I use (GPS Status, GPS Test) have any WAAS settings. Maybe they would if the hardware exposed them.

 

Does anybody's mobile have a WAAS-capable receiver?

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it would make sense if smartphones received their augmentation data through the cell/data network. i have no idea if that actually happens though.

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The GPS Status app has an option to "Download GPS Assistance Data". It's not clear whether other apps (like the Groundspeak app) do the same thing. And is that "assistance data" used by the hardware for all apps that use the GPS system, or only GPS Status?

 

The Garmin is quite a bit less confusing.

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The GPS Status app has an option to "Download GPS Assistance Data". It's not clear whether other apps (like the Groundspeak app) do the same thing. And is that "assistance data" used by the hardware for all apps that use the GPS system, or only GPS Status?

 

The Garmin is quite a bit less confusing.

 

HTC's QuickGPS app (and similar tools on HTC Platforms) is not for WAAS/Augmentation data it's for Almanac data to obtain an initial position fix quicker, particularly when aGPS data is not available from cell towers (ie Airplane mode)

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HTC's QuickGPS app (and similar tools on HTC Platforms) is not for WAAS/Augmentation data it's for Almanac data to obtain an initial position fix quicker, particularly when aGPS data is not available from cell towers (ie Airplane mode)

Ummm ...

 

Surely, when your phone is in "Airplane" mode, ALL transceivers are turned off, so you won't get data from the cell-phone network OR from WiFi OR from Bluetooth, so the HTC QuickGPS app (and similar apps) won't work anyway. (Or am I missing something?)

 

The GPS receiver, however is only a receiver, not a transmitter, so should be able to continue to work even when in Airplane mode. (It certainly works this way on my HTC Wildfire Android.)

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JulianH, you're not missing anything but the terminology and implementations can be confusing. I can't speak of the HTC, but will offer the iPhone for comparison.

 

On the iPhone, when you first hit "Airplane Mode" it does shut off all transceivers. While still in Airplane Mode though, you can flip the separate toggle to turn WiFi back on. Even though that control is simply labeled "WiFi" it does also re-enable the GPS. BlueTooth gets shut off when you enable Airplane mode but can also be re-enabled by a control on a separate prefs screen.

 

I find this one of the more confusing/annoying aspects of the iPhone and don't know if any other phones handle it any better. I'd really like ONE preference panel that lets me flip on and off all of the individual radios; but the iPhone has them scattered across numerous screens.

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I just compared my Droid X with my Delorme PN-30. They received the exact same satellites except the Delorme showed the WAAS bird and the Droid did not. The coords were essentially the same.

 

I am guessing that phones do not get WAAS just as GPSrs for cars do not.

 

In my tests on top of super-accurate benchmarks, turning WAAS on and off, with several brands of GPSrs, there was usually very little difference to maybe a couple of feet difference.

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In my tests on top of super-accurate benchmarks, turning WAAS on and off, with several brands of GPSrs, there was usually very little difference to maybe a couple of feet difference.

the problem with this is that you don't know how much the difference really is. as you say, most of the time the difference will be very little and might even be zero. on bad days on the other hand, the difference can be several meters. without WAAS/EGNOS you don't know, but with it you do because part of the error is elminated. that's why the "accuracy" reading on a WAAS/EGNOS-enabled receiver is higher than on one without it.

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HTC's QuickGPS app (and similar tools on HTC Platforms) is not for WAAS/Augmentation data it's for Almanac data to obtain an initial position fix quicker, particularly when aGPS data is not available from cell towers (ie Airplane mode)

Ummm ...

 

Surely, when your phone is in "Airplane" mode, ALL transceivers are turned off, so you won't get data from the cell-phone network OR from WiFi OR from Bluetooth, so the HTC QuickGPS app (and similar apps) won't work anyway. (Or am I missing something?)

 

The GPS receiver, however is only a receiver, not a transmitter, so should be able to continue to work even when in Airplane mode. (It certainly works this way on my HTC Wildfire Android.)

 

You run QuickGPS at least once every 7 days. It downloads the Almanac to use later (but during the 7 days valid time) to figure out where the GPS satellites should be without requiring aGPS data on the spot. HTC QuickGPS normally automatically runs once a week, but you can trigger it immediately if you want.

 

The *intent* is for use when without a data connection. I use it to help my TouchPro2 get a GPS fix without having a cellular data plan on that phone (since I moved to iPhone) ... I just connect up to WiFi and run QuickGPS to get the Almanac. Otherwise the unit can take 5 minutes to get a GPS fix from a cold start.

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JulianH, you're not missing anything but the terminology and implementations can be confusing. I can't speak of the HTC, but will offer the iPhone for comparison.

 

On the iPhone, when you first hit "Airplane Mode" it does shut off all transceivers. While still in Airplane Mode though, you can flip the separate toggle to turn WiFi back on. Even though that control is simply labeled "WiFi" it does also re-enable the GPS. BlueTooth gets shut off when you enable Airplane mode but can also be re-enabled by a control on a separate prefs screen.

 

I find this one of the more confusing/annoying aspects of the iPhone and don't know if any other phones handle it any better. I'd really like ONE preference panel that lets me flip on and off all of the individual radios; but the iPhone has them scattered across numerous screens.

 

Mine is jailbroken and I have an app that will only shut off the phone, so it doesn't completely enter airplane mode. I believe the app is SBSettings

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Broadcom's new GPS chipset, the BCM4752 has SBAS capability (WAAS, EGNOS - unsure about MSAS & GAGAN, but they should work). I'm guessing this would lend to an accuracy improvement of the provided position, but it is unclear if any apps would be able to utilize or display WAAS specific data (ie - GEOs tracked, the GPS satellites you've received corrections for, etc). I would guess the best bet on Android would be the "GPS Status & Toolbox" app, but not sure if they support display of WAAS data. This chipset can be found in the Samsung Galaxy S4. Not sure it is in any other phones though.

 

SBAS corrections are different from what is downloaded via A-GPS. A-GPS is almanac and ephemeris data for the GPS satellites to improve your time to first fix. Using GPS only, it might take 12 minutes or more to acquire this data since GPS bit-rate is so low. Downloading this data via your mobile data is much faster (on the order of several seconds). This information simply tells the receiver where in the sky to look (precisely), and for what satellite to look for in that spot. This can drop your time to first fix to seconds, rather than minutes. The GPS status app on Android has an A-GPS tool where you can manually force the download of this information.

 

SBAS correction messages are 250-bits per second sent down from three geosynchronous satellites (currently PRNs 133, 135, 138 for WAAS). These PRNs might show up in some displays as 46, 48, and 51 respectively (subtract 87). These are the NMEA satellite values. These messages provide corrections for sources of GPS error (satellite clock drift, satellite ephemeris, ionospheric error, tropospheric error, system time corrections, etc). The messages also include ephemeris data for the system's GEOs, so they can be used as a ranging source similar to GPS satellites.

 

Currently there are no internet sources for WAAS real-time correction data. EGNOS has SISNET, where you can stream the 250 bps over the internet rather than acquiring it from their geosynchronous satellites. No apps that I know of utilize the online stream and integrate the corrections, but EGNOS put out a dev kit, so the apps might be coming.

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Funny that you just referenced a web site that I administer :-). While that page does have WAAS data decoded to a text output updated every three minutes, it is not a real time stream of the binary 250 bit messages that are broadcast from the WAAS GEOs every second. The SISNET service for EGNOS serves up a real time stream (think streaming radio) that contains the same messages broadcast from their GEOs. The Euro government org contracted this out and paid a lot of money to provide this service. WAAS has no similar online stream available.

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