New Android devices offset location

[sv_pelagia]

I believe "precise location" is gps PLUS internet-determined location.

Use gps only, not oddly named "precise".

[requiem]

The Dashboard plugin allows display of GPS status. I would hope that includes HPE, but I don't have an Android phone. Perhaps there's another built-in way to display estimated position error? It is somewhat vital. However, I'd expect Navionics to be similarly impacted in such a case. It's also possible the CM93 charts could be offset, but that's unlikely to happen by accident and would be reveal by comparing coordinates.

Bruce, I'm assuming the marks you dropped were at the same physical features (e.g. same buoy, same headland, etc) on both charts. Having done that, and seeing they share the same coordinates, should rule out a datum* error or a chart shift problem.

* Since the planet is lumpy, a spheroid with lat/lon grids is used to approximate it. Particularly in the past different places would use a spheroid that better fit the local area, but these days the default standard is called WGS84. Generally the differences aren't incredibly large, for example in North America the same coordinates in NAD27 and NAD83 will probably differ only by a few hundred meters at most. It's a bit similar to in the past, when one country might count degrees of longitude starting from Paris, and another might start counting from Greenwich.

[requiem]

Originally Posted by sv_pelagia

I believe "precise location" is gps PLUS internet-determined location.

Use gps only, not oddly named "precise".

Should be the opposite; not using “precise” uses only WiFi/cellular to provide a less-precise location for privacy. The app, of course, will require access permissions for both.

[sv_pelagia]

Originally Posted by requiem

Should be the opposite; not using “precise” uses only WiFi/cellular to provide a less-precise location for privacy. The app, of course, will require access permissions for both.

Of course, you are correct. Android 12 makes this clear.

BUT: Earlier Android this is not so clear: for example, with Android 8, one has 3 choices:
> High Accuracy (gps, wifi, bluetooth or mobile networks to determine loc)
> Battery saving (wifi, bluetooth or mobile network)
> Device only (gps)

When out on boat, I always chose "Device only", rather than "high accuracy"

Hence my previous answer.

[wholybee]

Originally Posted by sv_pelagia

Of course, you are correct. Android 12 makes this clear.

BUT: Earlier Android this is not so clear: for example, with Android 8, one has 3 choices:
> High Accuracy (gps, wifi, bluetooth or mobile networks to determine loc)
> Battery saving (wifi, bluetooth or mobile network)
> Device only (gps)

When out on boat, I always chose "Device only", rather than "high accuracy"

Hence my previous answer.

Yes, that has always been confusing, and I don't think Android is honest about what is really happening. I'm not sure how using wifi et. al. makes it any more accurate. It DOES allow instant downloading of the almanac, which would otherwise take 12.5 minutes. And, it allows your location data to be used to populate Googles wifi database for location purposes.

I don't see how this can be a datum issue, unless there is some bug somewhere. As far as I can determine, Android is WGS84 and can't be changed. Perhaps somehow the GPS receiver gets changed to something else? But permissions are on a per-app basis. So, it is reasonable that permissions are correct for Navionics, but not for OpenCPN.

I am curious what the OP finds.

* I think you can force it to only use the GPS by turning on airplane mode, and then manually turning on location services *

[rgleason]

On my android cell A51 5g l
Settings > Location >Apps >Opencpn has Precise checked which is correct for this model. Uncheck gives imprecise location.

[rgleason]

Download GPS Status app in playstore and check your location lat long please.