A Covariance Study for Orbit Accuracy Improvement of the GPS Satellites Using Fiber Optics Tracking Open PDF Document Details Document Type Technical Report Publication Date Jan 01, 1991 Accession Number ADA237858 Entities People William Schreiner Tags DTIC Thesaurus Topics Accuracy Artificial Satellites California Covariance Fiber Optics Optics Oscillators Sea Level Simulations Technology Areas Space Space - Orbital Debris Space - Space Objects