Steven White of Green Bank Observatory

The 100 meter Green Bank Telescope is the largest steerable radio telescope in the world.  The telescope is equipped with a suite of cryogenic receivers, has an advanced digital control system, and has adequate surface accuracy to provide frequency coverage from 300 MHz to 115 GHz.  A variety of objects in the universe emit energies observable in this broad frequency range.  Gravitational time delays predicted by the general theory of relativity are quantified by arrival time deviations from pulsars in binary systems.  Accurately timing an ensemble of pulsars from different celestial coordinates has the potential to detect low energy gravitational waves.  Studying these phenomenon has fueled advancements in digital signal processing techniques needed to fully understand the physics involved.  Multi-beam high frequency receivers along with broad band spectrometers has enabled mapping of the galaxy in search for star forming regions, and led to the detection of extraterrestrial organic molecules.  Accurately measuring the Doppler shift form extragalactic water masers requires high spectral resolution.  The precision constrains the Hubble Constant value which is a parameter needed to predict the age of the universe in cosmological models.

Biography:

Steven White currently serves as the Electronics Division Head for the Green Bank Observatory. Previous to this position, he led the Microwave Group for eleven years.   During his tenure the group improved the site scientific capabilities by developing a seven-pixel K-band cryogenic receiver, and a dual beam V-band cryogenic receiver.  He has developed solutions for analog fiber optic gain instabilities and continues to be interested in reducing the polarization sensitivity in fiber optic photo-detectors.  Recent projects include the L-band phase array feed receiver, a fiber optic based laser range finder, and a high mass flow cryogenic compressor.  Other interests include feed horn design, low noise receiver testing and characterization, and modular microwave circuit design.

Steven graduated magna cum laude with a Bachelor of Science Degree in Electrical Engineering from North Carolina State University.  He also matriculated at the Georgia Institute of Technology obtaining a Master of Science Degree.