Do I need this backend?

[wretchedneo]

My device has a bad gps module in it, it takes very long to lock to nearby sattelites with no external location provider i.e. (unifiednlp, microg)

I recently tried unifiednlp by installing it and the backends I thought I needed as system apps with appropriate permissions.
I installed these:

• apple unifiednlp
• localnlp backend (your backend)

( I also installed nominatim-geocoder but that is a hard dependency, therefore I wont mention it again)

everything works fine now, gps locks within 10 seconds, and maps apps are working properly. but the device has to be connected to a wifi network to do all this.

I examined that localnlp is almost doing nothing and only applenlp is doing all the work.

After which i tried to remove unifiednlp completely and fresh installed it but this time only with applenlp.

I found out that location still works even with applenlp (with wifi connected)

Here is my question now, do i still need localnlp even after gps works fine with applenlp alone?

If yes, what advantages can it provide over just using applenlp?

[Helium314]

The Local NLP Backend initially comes without data. You can either gather data (i.e. nearby WiFis and mobile cells) with actual GPS (not really working on your phone), or by loading data from another source.
Data from other sources usually was Mozilla Location Services, but that doesn't exist any more. Or use OpenCelliD.

Both MLS and OpenCelliD only have / had mobile cell data for download, which means low accuracy.
If you're fine with low accuracy locations (often hundreds of meters off), then you can try download your countrie's cell data from OpenCelliD to make Local NLP Backend work. But if that's not good enough for you, then you can kick it out and only use the Apple backend.

[wretchedneo]

@Helium314 I believe I should build my own nlp database using your backend for freedom and emergency situations.

Using apple nlp does provide quick location fixes, but it is not sustainable and does not work without internet.

Therefore i will be using local nlp in conjunction with apple nlp to slowly build my own database.

Do I have to go to different locations to improve the database coverage and speed it up?

[wretchedneo]

Also can the 'kalman filter' feature in your backend provide some aid in my situation?

[Helium314]

If you want to build the database, starting data from OpenCelliD / MLS might be a good idea.

Do I have to go to different locations to improve the database coverage and speed it up?

Yes. LocalNLP adds data when you are at a location and have GPS enabled. You can also use the active mode from the settings, but since you said it takes very long to get a GPS signal this might not work. Alternatively you could just keep GPS on all the time for a while / if you go to "new" places, but this will of course drain your battery.

Also can the 'kalman filter' feature in your backend provide some aid in my situation?

The filter helps if your GPS location is jumping considerably, but otherwise will barely have any effect. If it just takes very long to get a GPS fix then the Kalman filter won't help.

[wretchedneo]

If you want to build the database, starting data from OpenCelliD / MLS might be a good idea.

You are right that will give me a good base to start off, I will try this tomorrow

Yes. LocalNLP adds data when you are at a location and have GPS enabled. You can also use the active mode from the settings, but since you said it takes very long to get a GPS signal this might not work.

I have some questions regarding this

• can local nlp store the location fixes (coordinates) provided by apple nlp in it's own database?
• is turning on mobile data beneficial to this process in any way?

[Helium314]

can local nlp store the location fixes (coordinates) provided by apple nlp in it's own database?

No, it only takes GPS data as input coordinates.

is turning on mobile data beneficial to this process in any way?

No, that doesn't help at all with Local NLP Backend

[wretchedneo]

Is this the same thing as what is mentioned by you in the 2nd stanza of this section?

The screenshots are from this app.

[wretchedneo]

Adding on my previous message, when I clicked on the map icon inside the app, a popup like this appeared where I opened the url with localnlp 'just once'

[Helium314]

Oh right, I forgot about this feature.
You can open a location with Local NLP Backend, and it's the same as if you had GPS at this spot. So you can also build up the database this way. Very tedious though if you want to add a lot of locations.