Dual-frequency identification sonar (DIDSON)

Dual-frequency identification sonar (DIDSON) is a specialized underwater imaging technology that uses high-frequency sound waves to see and identify objects beneath the water's surface. It emits two different sound frequencies simultaneously, allowing it to produce detailed images of underwater environments and detect fish, structures, or obstacles even in turbid or murky water. DIDSON operates similarly to an underwater camera but uses sound instead of light, making it highly effective for marine research, fish counting, and navigation in challenging visibility conditions.