I think one upside of the SteamVR base stations is that you don’t need a wire back to the computer - they are pretty much just laser lighthouses that just need a plain power connection, meaning you can put them in all sorts of places without worrying about the return wire. The lase pulse that rotates (both horizontally and vertically) around the room includes a timestamp encoded within it (in the pulses), that then allows the receivers on the headset (and controllers) to get an understanding of what they just saw and then place themselves in a 3D space accurately. Sort of like a mini GPS, but with light you can’t see (which I guess is radio signals, but you get what I mean).
A valid question is ‘How does this work with just one lighthouse?’ and the answer is that the headset and controllers have several sensors on them ‘looking’ in different directions (slightly), so they triangulate using that as the light hits each sensor in turn (very quickly), e.g. the ‘cameras’ on the non-light emitting end make the angles. Here’s a neat mock up of them working - the flash is used to synchronize with other emitters and the receivers.
The drums literally spin with reflectors for the beam…
