Hard to imagine that there are places not surveyed - at least over here in the States.
Would be a very cool 6 month deployment. Perhaps our South African members could provide some insight on how things would be carried out.
https://www.mediacentre.go.ug/news/president-announces-govt-effect-universal-land-surveying
Mexico undertook a similar project about 20 years ago, they wanted to give title to small landowners (ejidos) so that they could get bank loans. If I recall correctly they bought 600+ GPS units to get the job done. I do not know how that turned out, though.
My sister spent 4 months in Uganda in 2011, and I was fortunate enough to visit for two of those weeks. We were in Jinja mostly, but we traveled all over.
Beautiful country, great people, great coffee, and the BEST pineapple I have ever had.