James L. Farrell (MS, UCLA, Ph.D., U. of MD,) is former ION Air Representative, a Life Senior Member of IEEE, former local board member of AIAA, registered professional engineer in Maryland, and member of various scholastic honorary fraternities. Technical experience includes teaching appointments at Marquette and UCLA, two years each at Minneapolis Honeywell and Bendix-Pacific, plus 31 years at Westinghouse in design, simulation, and validation of navigation and tracking programs. He is author of INTEGRATED AIRCRAFT NAVIGATION (Academic Press, 1976; now in paperback after five hard-cover printings), and of GNSS AIDED NAVIGATION AND TRACKING (2007) - both distributed by NavtechGPS, as well as chapters in books edited by C.T. Leondes and Cary Spitzer. He has written columns for GPS World, several more for WASHINGTON TECHNOLOGY, and over 80 journal and conference manuscripts. He served as co-chairman of RTCA Working Group for GPS Integrity. With VIGIL Inc. he has continued his teaching (on University campus and in seminars - industry, conference, IEEE, and on-site), while consulting for private industry, DoD, and University research. Main areas of recent activity are GPS/inertial integration, calibration, and integrity, writing programs validated with test data from Ohio University.