MultiNav Pro+ BLE 50km range - line of sight only or does it hold up with obstacles?

@William Taylor yeah so the 50km spec is specifically the drone-to-drone number — both modules elevated, no ground reflections eating into the link. For your ground-fixed node setup you're looking at the 5km ground-to-ground figure as the more honest baseline.

 

That said, rural terrain with rolling hills and a few treelines is genuinely one of the better real-world environments for this — it's not urban RF chaos. Your actual range will land somewhere between those two numbers depending on how high you can mount the antennas. Even getting a node up on a pole a few meters off the ground makes a meaningful difference, and if you can achieve line-of-sight between antenna positions even partially, you'll recover a lot of that headroom.

 

The grain silos are probably your worst-case obstacle — metal structures will reflect and attenuate more aggressively than trees. If you can plan node placement to avoid putting a silo directly in the path between two nodes, that's worth doing. If you can't, it's worth doing a quick site survey with two units before you commit to final pole positions.

The 50km spec is basically best-case LOS on flat ground with no interference, so yeah, rolling terrain and hard obstacles like silos are gonna eat into that range pretty significantly. In my experience with similar setups you're probably looking at 30-40% reduction depending on how bad the obstructions stack up between nodes. Worth planning your node placement around the highest elevation points you can find and maybe budgeting for a few relay nodes just in case.

Michael's numbers track with what I've seen too - I'd honestly lean toward the lower end of that estimate if any of those silos are metal, they're surprisingly brutal on signal. Definitely get your relay node budget sorted before you finalize placement, because retrofitting extra hops into a deployed network is a pain.

Both of those points are solid - metal silos are basically signal killers, I'd treat any node with a silo in the path as basically needing a relay by default rather than hoping it punches through. One thing that's helped me with similar deployments is throwing the node coordinates into a terrain profile tool (HeyWhatsThat or even just Google Earth's elevation profile) before committing to placement, saves a lot of guesswork about what's actually in the Fresnel zone between nodes.

Joseph's point about Fresnel zone clearance is the one I'd really hammer home here - people fixate on the straight-line path being "clear" but even partial obstruction of that first Fresnel zone can tank your link budget worse than you'd expect. I'd run the terrain profiles before you even think about final node placement, and honestly if a silo falls anywhere near that zone just assume you need a relay and size your BOM accordingly.