1. The spread of disease (smallpox specifically) being fast enough that most European sources describe a relatively uninhabited Amazon strikes me as potentially interesting. This means that contact and trade was happening between locales. We know that part is true from many sources, but:
A) Can we roughly model the spread of smallpox by looking for (for example) populated areas mentioned in one European source that are unmentioned, or mentioned as empty, by another source that would have likely crossed paths with that civ?
B) Can this tell us anything about trade routes and volume? Can we make any inferences about pop density, even very weak inferences, which might help us know where to look for stronger evidence? It does seem like each European discovery historically revises the estimated population(s) upwards.
2. LiDAR is awesome. Maybe not in the Amazon - in less foliage-dense places - is it being combined with, for example, an EMF (or some other kind of more granular lightweight detection system) - strapped to a drone?
It feels like once we see something interesting on LiDAR, sending a swarm of lightweight drones with some kind of metal detector sellotaped to the underside is quite a quick way to get interesting information. I don’t know a lot about radio waves, so I don’t know if there’s a suitably lightweight detector for this purpose.