size can be an indication of depth. Plus a lil number on the pawn can say all 3 coords.

that's a maritime maneuvering board. A more in-depth article I looked at from the same website: http://gcaptain.com/maritime/tools/files/MoBoard.pdf it seems like its for navigating oceans, rather than space, which still makes sense I think in destiny's context given the Puerto Princessa coastline map. there's one thing that stands out to me at first glance though: this board functions as a complete grid of values, while the radial seems incomplete. there are many spaces and breaks in what is otherwise quite structured. I'll include this as part of the speculation in the OP though, as even though it might not be exactly what the radial is, I think its a step in the right direction.