System Identification Approach Applied to Drift Estimation

A system identification approach is applied to estimate the time base drift introduced by a high-frequency sampling oscilloscope. First, a new least squares estimator is proposed to estimate the delay of a set of repeated measurements in the presence of additive and jitter noise. Next, the effect of both additive and jitter noise is studied in the frequency domain using simulations. Special attention is devoted to the covariance matrix of the experiments, which is used to construct a weighted least squares estimator that minimizes the uncertainty of the estimated delays. Comparative results with respect to other state-of-the-art methods are shown. Finally, the enhanced method is applied to estimate the drift observed in repeated impulse response measurements of an opto-electrical converter using an Agilent 83480A sampling oscilloscope in combination with a 83484A 50 GHz electrical plug-in.