Chris Ruf
NASA Cyclone Global Navigation Satellite System (CYGNSS) Earth Venture Mission

Wednesday, May 6, 2015
Building 3 Auditorium - 11:00 AM
(Coffee and cookies at 10:30 AM)

The NASA Earth Venture Cyclone Global Navigation Satellite System (CYGNSS) is a spaceborne mission focused on tropical cyclone (TC) inner core process studies. CYGNSS attempts to resolve the principle deficiencies with current TC intensity forecasts, which lie in inadequate observations and modeling of the inner core. The inadequacy in observations results primarily from two causes: 1) Much of the inner core ocean surface is obscured from conventional remote sensing instruments by intense precipitation in the eye wall and inner rain bands. 2) The rapidly evolving (genesis and intensification) stages of the TC life cycle are poorly sampled in time by conventional polar-orbiting, wide-swath surface wind imagers. CYGNSS is specifically designed to address these two limitations by combining the all-weather performance of GNSS bistatic ocean surface scatterometry with the sampling properties of a constellation of eight satellites. The use of a dense constellation of microsatellites results in spatial and temporal sampling properties that are markedly different from conventional imagers. An overall mission design summary will be presented. Simulation studies examine the expected spatial and temporal sampling as functions of various orbit parameters of the constellation. Historical records of TC storm tracks are overlaid onto a simulated time series of the surface wind sampling enabled by the constellation. For comparison purposes, a similar analysis is conducted using the sampling properties of several past and present conventional spaceborne ocean wind scatterometers. Differences in the ability of the sensors to resolve the evolution of the TC inner core are examined.

Chris Ruf is Professor of Atmospheric Science and Electrical Engineering and Director of the Space Physics Research Laboratory (SPRL) at the University of Michigan. He is Principal Investigator of the NASA CYGNSS Mission. He has been involved in microwave remote sensing for 30+ years, with a research emphasis on spaceborne microwave sensor design and calibration and the development and validation of ocean and atmosphere geophysical retrieval algorithms. He is also involved with related technology development efforts. His involvement with spaceborne missions includes instrument scientist for TOPEX and GeoSat Follow On and science or cal/val team member for five missions (Jason, WindSat, Aquarius, Global Precipitation Measurement and Juno). Prof. Ruf is a Fellow of the IEEE and former Editor-in-Chief of the Transactions on Geoscience and Remote Sensing. SPRL is a research unit at the University of Michigan specializing in the design, fabrication and operation of spaceborne scientific instruments. It has developed and flown over 38 successful spaceflight sensors since its founding in the 1950s.
IS&T Colloquium Committee Host: Jacqueline LeMoigne

Sign language interpreter upon request: 301-286-7040