Synergy between Global Navigation Satellite System and Very Long Baseline Interferometry space geodesy techniques.

The NASA Postdoctoral Program (NPP) offers unique research opportunities to highly-talented scientists to engage in ongoing NASA research projects at a NASA Center, NASA Headquarters, or at a NASA-affiliated research institute. These one- to three-year fellowships are competitive and are designed to advance NASA's missions in space science, Earth science, aeronautics, space operations, exploration systems, and astrobiology. This specific opportunity focuses on developing methods of data analysis for an emerging VLBI+GNSS technique, identifying areas of strengths and weaknesses of the new technique, optimizing observing programs, processing data, and presenting evidence that substantiates claims about strengths and weaknesses. Recent advances in space geodesy instrumentation and data analysis have allowed the blurring of lines between very long baseline interferometry (VLBI) and global navigation satellite systems (GNSS) techniques, enabling observations of GNSS satellites with VLBI, use of GNSS receivers as VLBI array elements, and determination of pseudo-ranges from voltage data of GNSS satellites recorded with radio telescopes. This is a new research area categorized as high risk, high reward. NASA heavily contributes to the ongoing international geodetic VLBI observing program for determination of terrestrial coordinate system, celestial coordinate system, and determination of the Earth orientation parameters with the highest accuracy.