August 17, 1996


Artist's concept of the NASA Scatterometer

Artist's concept of the NASA Scatterometer


The NASA Scatterometer instrument, designed and built at JPL, launches aboard Japan's Midori satellite. A scatterometer is an instrument that measures near-surface ocean winds by sending a constant stream of radar pulses toward Earth from an orbiting satellite. When the radar pulse reflects back off the ocean surface, some of its energy is scattered by small, wind-driven waves rippling across the sea. By measuring these changes in the reflected radar signals, engineers can deduce the speed and direction of the winds that caused the ocean waves.

The scatterometer yields 268,000 measurements of ocean winds each day, covering more than 90 percent of Earth's ice-free seas. This information is critical in determining regional weather patterns and global climate.

Nine months after launch, the Midori satellite loses power, ending the mission. NASA approves a rapid replacement mission called the Quick Scatterometer to replace the lost instrument.

See also: Scatterometers

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