RTK rover comparison under tree canopy - which receivers actually hold fix?

Been doing a lot of topo work in partially wooded residential lots lately and the canopy is killing my RTK fix rate. Figured I'd share some informal testing I did last week comparing three receivers under moderate to heavy tree cover.

Tested an Emlid RS2+, Trimble R12i, and a Javad Triumph-3. Same site, same NTRIP mount point, same afternoon. The site has a mix of open lawn, scattered oaks (maybe 40% canopy), and a section of dense pines that's probably 80%+ coverage.

In the open area all three held fix no problem, as expected. Under scattered oaks the RS2+ was dropping to float every few minutes while the Trimble and Javad stayed fixed. Under the dense pines nothing held fix reliably but the R12i was noticeably better - I'd get fix for maybe 30 seconds at a time vs the others barely getting fix at all.

The Trimble's tilt compensation also helped a lot under canopy since you dont have to hold the pole perfectly plumb while waiting for a fix. Small thing but it adds up when your fighting branches.

My takeaway - if canopy work is a big part of your business, the premium receivers earn their price. If its occasional, you can work around it with longer occupations and more QC. The RS2+ is great for open sky work at a fraction of the cost but it struggles once you get above 50% canopy.