Speed Of Internal Ocean Wave Measured With Single Satellite Overpass

Internal waves at Dongsha Island on April 23, 2010, as seen by the radar on TerraSAR-X in its conventional mode of operation (left) and an experimental mode that permits direct velocity measurements (right). (Credit: German Aerospace Center (DLR) 2010)

Though they can be as tall as skyscrapers, internal ocean waves rarely break the surface, making it more difficult to determine their speed. But researchers at the University of Miami have managed to determine the speed of one massive wave using a single satellite overpass, according to a release from the school. Previously, multiple satellite overpasses were needed to determine wave speed.

The feat was accomplished using a German TerraSAR-X satellite’s radar, which provided a single-pass image. The single-pass image was noisy and required further processing by UM’s Center for Southeastern Tropical Remote Sensing (CSTARS) before the internal wave speed could be determined.

CSTARS enhanced the internal wave patterns in the image to accurately gauge its wave velocity. Only CSTARS and the German Aerospace Center are currently capable of processing the images correctly to ascertain internal ocean wave speeds.

The movements of internal ocean waves are important because they move large amounts of heat, nutrients and salt across the ocean, which affect fish, marine industries and global climate.

Top image: Internal waves at Dongsha Island on April 23, 2010, as seen by the radar on TerraSAR-X in its conventional mode of operation (left) and an experimental mode that permits direct velocity measurements (right). (Credit: German Aerospace Center (DLR) 2010)