Earth:Previsual

Previsual literally means "before seeing". Usually, it is applied to a means of detection of a phenomenon before its consequences are noticeable or irreversible. Previsual detection lies on the influence of the phenomenon on other indicators.

Example

An example of previsual detection would be that of plant stress (e.g., lack of water or nutrients) by means of its influence on sun-induced fluorescence emission of light by the leaves (Chappelle et al., 1984).

References

• Chappelle, E.W., McMurtrey, J.E., Wood, F.M., et al. (1984), Laser-induced fluorescence of green plants.
• LIF caused by nutrient deficiencies in corn, Applied Optics 23 (1): 139-142 1984