An airborne laser fluorosensor for the detection of algae in the sea has been developed. The system transmits dye laser radiation at 590 nm and monitors the fluorescent emission at 685 nm from chlorophyll-a a bearing microorganisms. The system was successfully flown over the test areas of Lake Ontario and Chesapeake Bay. The device is sensitive to a fraction of mg/M3 chlorophyll-a density in the water from an altitude of 30 m.
Hongsuk H. Kim, "New Algae Mapping Technique by the Use of an Airborne Laser Fluorosensor," Appl. Opt. 12, 1454-1459 (1973)