android phone version, does it use satellite gps or 4G?

[sdowney1]

A poster on boatdesign.net said his phone when running navigation apps, if he goes out of range of cell phone towers, the nav apps do not work? Claims they are using 4G data not GPS data to get fixes.

So, would like to know, do you know if an android nav app stops working?
Will the opencpn app continue to work if there is no cell signal?

You think his issue has to do with the non working app needing to download maps using 4G data?

[dwedeking2]

I have an GPS driven app that I use on an android. It will make a GPS track even if it can't download a map (out of cell tower range). So I don't the issue is the phone but maybe unique to the app (meaning the programmer chose to not use gps)

[four winds]

For me, OpenCPN and MxMariner work fine without a cell signal.

Currently using an inactive Samsung smartphone as a backup chartplotter. Update charts when a good WiFi is available. And use GPS Essentials to record the track of daysails to review on google earth at anchor.

Maybe some apps need a signal to download charts while underway, don't know. To save space in memory, don't know. But charts should be stored locally if that option exists. As it does in OpenCPN and MxMariner.

[CarCode]

I don't know about Android but I know about my old iPad tablet it was sold as 2 versions:
- one version without SIM card slot has only the so called AGPS which is not a real GPS chip.
- one version with SIM card slot which has a real GPS chip and is usable as navi at sea.

Gerhard

[rgleason]

Opencpn uses GPS and works out of towers

[StuM]

Navionics on Android definitely works offshore well out of range of any cell towers.

I develop Android apps, including ones which use location data.

A developer can't decide what is used to determine fixes (4G or GPS), they can only make calls to the operating system's "Location Services" to get a location.

It's the Operating System and User Preferences that determine how fixes are obtained.

The only reasons that an application would only work with cell data is if:

1. the user has set "Location Mode" to "Power Saving"( "Uses Wi-Fi and mobile networks to estimate your location") rather than "High Accuracy" or "GPS only"
or
2. he has a really cheap device which doesn't have GPS - but there are very few of them on the market.

(The above is of course only talking about location fixes. If an application needs a data connection to do other things such as download maps, then obviously that part of the app won't work outside of WiFi or Cell range, but location services still will. But I don't know of any navigation app that doesn't cache maps/charts for use outside of cell range).

[bdbcat]

StuM...

Concur with all.

Thanks
Dave

[Tkeeth]

Also depends on phone model. Android is an operating system, not hardware. It will work with gps if your device has the capability.

[sdowney1]

Thanks guys for this info.

[svseachange]

The answer is it depends on the app programmer and the Android device settings.

The app programmer chooses what level of location precision the app requests, the user of the Android device determines what level of location precision to provide.

App programmers tend to budget GPS precision because GPS precision locations drain batteries. This is becoming less of an issue as phone batteries improve.

You would think sailing app programmers would request GPS precision and Android users would provide it but this might not always be the case.

[Dymaxion]

I've had Sony and Samsung android based phones and both had proper GPS Hardware built in. Google maps for instance allows you you download map sections for offline use when out of cell phone reception.

[CarCode]

Downloading a map has nothing to do with GPS.

Gerhard

[Dymaxion]

Originally Posted by CarCode

Downloading a map has nothing to do with GPS.

Gerhard

Wasn't my point. Point was that those two Android based devices operate happily with full GPS functionality away from any cell reception. Just load the maps before you leave cell reception area, if not, then read lat/long and use a paper chart. Your choice.