Evaluation of Orbit and Clock Models for Real Time WAAS Jan 1, 1995· Tsai , Y. J. , Chao , Y. C. , Walter , T. Changdon Kee , Powell , D. , Enge , P. , Parkinson , B. W. · 0 min read Last updated on Jan 1, 1995 Authors Changdon Kee Professor ← Real-time Flight Demonstration of Wide-Area Differential GPS (WADGPS) Feb 1, 1995 The Ionospheric Delay Improvement of the Stanford WAAS Network Jan 1, 1995 →