rhettb writes: High above the Amazon rainforest in Peru, a team of scientists is conducting an ambitious experiment: a biological survey of a never-before-explored tract of remote and inaccessible cloud forest. They are doing so using an advanced system that enables them to map the three-dimensional physical structure of the forest as well as its chemical and optical properties. This sensor—built by engineers at NASA's Jet Propulsion Laboratory—is the first of its kind. The spectrometer can detect dozens of signals such as photosynthetic pigment concentrations, water content of leaves, defense compounds like phenols, and structural compounds such as lignin and cellulose. These signals can build signatures to distinguish individual plant species as well as other measures of forest condition.