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.