I am currently working with QField on my tablet (Samsung Galaxy Tab S5e) and my smartphone (Samsung Galaxy A40). Since the positioning accuracy on my devices is rather low (absolute best case ~3m on an open field with clear sky), I am looking for lowcost ways to improve it in real time. Due to the high costs, I don't want to use an external GNSS receiver.
I've read that with RTK networks accuracies can be improved to sub-meter levels if you have raw measurements from your GNSS receiver, use a Ntrip-client and have access to correction data. This discussion: GNSS raw measurements on Android: Does real time/post processing Differential techniques possible?, and this article and the corresponding video: https://www.gpsworld.com/how-to-achieve-1-meter-accuracy-in-android/; https://www.youtube.com/watch?v=vywGgSrGODU gave me an overview of the topic, but I am still missing some things:
In the mentioned article/video from 2018 it says that there might be apps in a few years which will offer high-accuracy positioning with your smartphone. Does anyone know of an app that has been developed in the meantime and that achieves sub-meter accuracies with the GNSS-data received from a smartphone?