Broad-spectrum imaging. [ His voice matches his pace, brisk and businesslike, as he drives the pole into the soil. They did discuss this before, but it doesn't hurt to go over it again. ] The cameras can "see" wavelengths invisible to the human eye - infrared, ultraviolet, x-ray. Even if we can't observe the flow of eksth'alva directly, we can still quantify its effects.

[ Temperature's the big one, obviously, with the rest included for completeness. He's still not sure the x-ray will provide enough relevant info to justify its inclusion, but ... this is really a survey more than anything, and Carlisle did agree to it. ]