How to achieve sub-meter accuracy in remote locations?

Stalemate

Activity: Create 3D reconstructions of geological outcrops. Using imagery from a DJI Phantom 4, and SfM-MVS algorithms. To orientate the SfM-MVS reconstruction I will use ground control points (GCPs). I require sub-meter accuracy to measure these GCPs.

Areas: Remote, places with no mobile or RTK networks. First project will be in southwest Tibet.

Question 1: Is a SBAS solution the best way to go (I do not need cm accuracy)?

Question 2: How can I find out the coverage of SBAS, India has GAGAN, does that cover Tibet? China also has SNAS, but is that functional? Where can I confirm the coverage before I find out in the field that I am not within range? Are there commercial SBAS that I can pay for that cover Tibet?

Question 3: What receiver do I look for? I believe that the Arrow 200 GNSS and the SXblue II+ GNSS receivers will do what I want? The Bad Elf GNSS Surveyor and Juniper Systems Geode are much cheaper, can they also work in Tibet?

Question 4: Is there a better (cheaper) solution that I am unaware of?

Question 5: How can I check if there is a RTK network available before I arrive to the field?

I appreciate any help.

Boyd

Good luck with your project and I hope you get some helpful responses. However, this is primarily a consumer-focussed site where people come to discuss inexpensive GPS devices for their cars or outdoor recreation...

Stalemate

I am hoping for a consumer grade solution (less than $2000), without setting up rovers and base stations. But maybe I cannot achieve that?

Boyd

My point was that most members of this site are using simple consumer products for everyday tasks like avoiding traffic when they drive to work, and not technically complex projects like yours. :)

Stalemate

Ah! I understand! Cheers.