2009 Fellow

Presented to: Dr. Michael S. Braasch

Citation: For contributions to understanding of multipath error and its mitigation, and for GPS education.


Dr. Michael S. Braasch, Professor of Electrical Engineering at Ohio University, is best known for his contributions which have added to our understanding of the error due to multipath in the code and carrier phase measurements of a GPS receiver, and have led to development of antennas, receiver architectures, and processing techniques to mitigate this error. The algorithm for estimation of the pseudorange error due to multipath (a.k.a. code-minus-carrier), which he refined and popularized, is now a standard, and his design of a multipath-limiting antenna for ground reference stations filled a crucial need in civil aviation's Ground- Based Augmentation System (GBAS).

That Dr. Braasch has contributed to civil aviation systems is no coincidence. Mike is a rarity – a top notch GPS researcher and teacher, and an instrument-rated pilot. He received the RTCA's William E. Jackson Award for the best dissertation in the avionics area in 1992 for his work on multipath, and now serves as director of Ohio University's Avionics Engineering Center.

Mike first drew the attention of the GPS community as a graduate student with his mathematical model of Selective Availability, which he developed shortly after the launch of the first SA-capable Block II satellites in 1989. The model quickly became the de facto standard in the GPS community for evaluation of GPS' positioning capability while SA held sway. This model is described in one of his two chapters in the Global Positioning System: Theory and Applications, edited by Parkinson, Spilker, Axelrad, and Enge. Thankfully, the SA era, and this model, are now history.

Mike is also among the pioneers of software-defined radio for GPS and GLONASS. Indeed, the credit for the first demonstration in the mid-1990s of the direct-sampling GPS and integrated GPS-GLONASS architectures along with transform-domain acquisition techniques belongs to Dr. Braasch and his Ph.D. student Dennis Akos, and a team led by Dr. James Tsui at WPAFB. Ten years later, GPS software radio is one of the hottest areas of GPS research.

Professor Braasch teaches EE courses, including GPS receiver design, and has supervised about two dozen master's theses and Ph.D. dissertations at Ohio University in his 15-year career as a professor and researcher. He has won awards for excellence in both teaching and research, and he is currently O.U.'s Thomas Professor of Engineering (an endowed chair at O.U.).

A member since 1989, Mike has served the ION in several capacities: central region member-at-large and central region vice president (mid- 1990s); program chair and general chair of the ION's Annual Meetings in 1998 and 1999, respectively. He also served for several years as the ION finance chair.