NASA has selected an ocean-wind study led by Principal Investigator Chris Ruf of the University of Michigan to receive $151.7 million in funding over five years for a NASA mission involving small spaceflight investigations of the Earth system. Dr. Ruf earned his Ph.D. at the UMass Amherst Electrical and Computer Engineering Department, and his advisor was Emeritus Professor Calvin Swift. The mission will use a constellation of small satellites carried into orbit on a single launch vehicle.

Ruf’s project, entitled the Cyclone Global Navigation Satellite System (CYGNSS), will enable scientists for the first time to probe key air-sea interaction processes that take place near the inner core of storms, which are rapidly changing and play large roles in the genesis and intensification of hurricanes.

The CYGNSS measurements also may provide information to the hurricane forecast community.

In general, the NASA mission will make accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes, which could help lead to better weather forecasting. The NASA funding includes initial development, launch, deployment, and data analysis.

Ruf is the director of the Space Physics Research Laboratory, a Professor of Atmospheric, Oceanic, and Space Sciences, and a Professor in Electrical Engineering at Michigan. His specialty is Earth and Planetary Remote Sensing.

Among his many awards and honors, Ruf was an IEEE Fellow and a science team member on the NASA Jason-1 Microwave Radiometer and the NASA Aquarius Microwave Radiometer. He received NASA Group Achievement Awards for a lightweight rainfall radiometer, a TOPEX joint verification team, a TOPEX precision orbit determination, a TOPEX microwave radiometer, a piezoelectric reflecting array for reflector surface distortion compensation, a synthetic aperture interferometric radiometer image reconstruction error analysis, and a sparse aperture interferometric radiometer.

Professor Ruf also developed new method for estimating the depth of the marine boundary layer from space using horizontal turbulence structure of vertically integrated atmospheric water vapor; developed a new method for absolute and relative calibration of spaceborne microwave radiometers using lower bound on a cumulative statistic of the measured radiance; and pushed several technologies needed to fly synthetic thinned aperture radiometer in space.

The competitively-selected Michigan proposal includes partnerships with the Southwest Research Institute of Texas, Surrey Satellite Technology of Colorado, and NASA Ames Research Center.

Once in orbit, CYGNSS's eight micro-satellite observatories will receive both direct and reflected signals from Global Positioning System (GPS) satellites. The direct signals pinpoint CYGNSS observatory positions, while the reflected signals respond to ocean surface roughness, from which wind speed is retrieved.

"The CYGNSS mission is both a scientific and a programmatic advance for NASA’s Earth science and applications program," said John Grunsfeld, NASA's Science Mission Directorate associate administrator in Washington. "CYGNSS will provide vital science data on tropical cyclones, and the CYGNSS team will advance our ability to obtain high-quality Earth science data through smaller, more affordable space systems." (July 2012)