2004 Weems Award

Presented to: Mr. Curtis A. Shively

Citation: For his continuous significant contributions to the understanding and rigorous statistical analyses of air navigation operational requirements with respect to their impact on GNSS augmentation system design alternatives.


Curtis A. Shively is a principal navigation engineer in the Center for Advanced Aviation Systems Development (CAASD) of The MITRE Corporation in McLean, VA. For over 28 years he has been involved in the application of GPS to civil air navigation as pursued by the Federal Aviation Administration (FAA).

When GPS was first being considered for civil aviation applications, Mr. Shively was a key contributor to the design and implementation of a real-time GPS non-precision approach simulation consisting of a general aviation aircraft trainer interfaced to a minicomputer that calculated lateral deviations based on a GPS constellation model, receiver simulation and position solution.

Mr. Shively subsequently became a key member of a team working on the early defi nition of concepts for the FAA's Local Area Augmentation System (LAAS) for precision approach applications. Over many years of involvement with LAAS he was a key participant in RTCA standardization activities leading to the LAAS MASPS and MOPS, FAA standardization activities leading to the LAAS ground facility specification and was also a key member of the FAA's LAAS Integrity Panel that provided technical review of the precision approach concepts of both domestic and foreign avionics manufacturers.

Some of his specific technical contributions in those activities include: critical satellite concept used today in all continuity and availability determinations; design of Markov Chain-based availability model and its application to evaluate alternative LAAS architectures; early experimental verification of multipath reduction through averaging multiple reference receivers; performance requirements for multiple LAAS receiver consistency checks; and standards for maximum acceptable pseudorange errors resulting from ground monitoring for satellite faults. He also provided a rigorous analytical corroboration of a Boeing concept to signifi cantly increase the vertical alert limit for CAT IIIb autoland operations and thereby overcome the main availability limitation of LAAS.

Currently, he is studying the use of LAAS technology to provide a local monitor for ensuring the integrity of WAAS for lower landing decision heights than currently permitted by the WAAS broadcast integrity parameters. He received his B.S. and M.S. degrees in electrical engineering from M.I.T.