Airborne Elastic Backscatter and Raman Polychromator for Ash Detection

Volcanic ash is a significant hazard to aircraft engine and electronics. It has caused damage to unwary aircraft and disrupted air travel for thousands of travelers, costing millions of dollars. The small, jagged fragments of rocks, minerals, and volcanic glass that constitute volcanic ash are about the size of sand and silt. Volcanic ash is hard, does not dissolve in water, is extremely abrasive and corrosive, and conducts electricity when wet. The upper winds transport the particles away to eventual dispersal in an ash cloud. Ash clouds typically form above 20,000 feet, but the lower limit of the initial cloud depends on both the height of the volcanic vent and the vigor with which material is ejected from it.