The NASA CYGNSS Satellite Constellation Tropical Cyclone Mission

The Cyclone Global Navigation Satellite System (CYGNSS) is a confirmed NASA mission scheduled for launch in October 2016 that is specifically designed to study the surface wind structure in and near the inner core of tropical cyclones. CYGNSS consists of a constellation of eight small observatories carried into orbit on a single launch vehicle. Each observatory carries a 4-channel bistatic radar receiver tuned to receive GPS navigation signals scattered from the ocean surface. The distortion to those signals caused by ocean surface roughness is detected and used to estimate the wind speed at the surface. Performance is unaffected by the presence of precipitation, even at levels found in the eyewall and inner core rain bands of a hurricane. The eight satellites are spaced approximately twelve minutes apart in the same orbit plane in order to provide frequent temporal sampling. Mission simulations predict a median(mean) revisit time of 3(7) hours at all locations between 38o N and 38o S latitude. Relative to existing wind monitoring satellites, CYGNSS is expected to provide significantly improved temporal resolution and spatial coverage, under all precipitating conditions, and over the full dynamic range of wind speeds experienced in a tropical cyclone.

An update on the current status of the mission will be presented. The mission design and the expected performance of the ocean surface wind measurements will be reviewed, with emphasis on the expected spatial and temporal sampling properties of the retrieved winds. Recent simulation results addressing the expected impact of CYGNSS data products on tropical cyclone and other tropical meteorology analyses will be summarized.

More information about the CYGNSS mission is available online at: www.nasa.gov/cygnss