I'm currently working in Vietnam as a climbing guide, but am putting my GIS skills to use by doing a side project for the company involving the mapping of climbing routes. Along with another employee who is an app developer, our goal is produce a digital guidebook for the area.
For this project to work for me, I need to be able to take fairly accurate GPS points, as there are features just a few meters apart from each other that need to be distinguishable, but obviously survey grade equipment is not and option for me here. I've been using the app GPS Averaging to take several hundred points for each location.
Despite taking these averages, I'm having very little luck achieving accuracy in my output points, and I suspect my precision is low as well because the in app reported error gets very low (0.8m) after about 20 collected points, then goes up to about 3m after 200-300 collected points. However when I import these points, the actual errors appear to be well beyond 3 meters.
What can I do to improve GPS point accuracy from a mobile device?
I've currently only worked on this with android devices, but have access to ios devices too if they provide superior GPS chips.