Process noise models Characterization of noise processes Firstly need samples of the process(often not easy to obtain Auto-correlation functions Power spectral density functions Allan variances(frequency standards) Structure functions(atmospheric delays) see Herring, T.A.,J. L. Davis, and I.I. Shapiro Geodesy by radio interferomet The application of Kalman filtering to the analysis of vlbi data. J. Geophy.,Res,95,12561-12581,1990 03/1802 12.540Lec1203/18/02 12.540 Lec 12 11 Process noise models • Characterization of noise processes – Firstly need samples of the process (often not easy to obtain) – Auto-correlation functions – Power spectral density functions – Allan variances (frequency standards) – Structure functions (atmospheric delays) – ( s e e Herring, T. A., J. L. Davis, and I. I. Shapiro, Geodesy by radio interferometry: The application of Kalman filtering to the analysis of VLBI data, J. Geophys. Res., 95, 12561–12581, 1990