Laser line scanning underwater reefs

laser scan mockupNOAA has outfitted their ship, the Hi’ialakai with some scanning equipment that will allow them to take fast and accurate surveys of the ocean floor. More specifically coral reefs.

In the past they’ve had to rely on survery by eye or photograph but that has been slow and meant they could only survery small areas. In order to know how reefs are changing over time they needed a benchmark to measure against.

Enter the laser line scanner.

That system, called the SM-2000, was built by Northrop Grumman, and is owned and operated by Scientific Applications International Corporation (SAIC). The SM-2000 consists of a solid state blue-green laser that is aimed at a rotating mirror assembly. The mirrors quickly sweep the laser light across a downward pointing arc, while detector optics record the light reflected back from the seafloor. Variations in the reflected light are used to generate a gray scale image of the seafloor – essentially a black and white photograph of a strip of the ocean bottom that may be about 100 ft wide and could extend for miles.

crab imaged through scanning

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