Measurements and estimation of the TIE of a crystal clock using an unbiased FIR filtering algorithm

An unbiased finite impulse response (FIR) filtering algorithm is investigated for the GPS-based measurements of a local crystal clock. The algorithm is examined for the time interval error (TIE) measurements in presence of the uniformly distributed sawtooth noise induced by the multichannel GPS timing receiver. Based upon, we show that the unbiased FIR estimates are consistent with the reference (rubidium) measurements and fit them better than the standard Kalman filter.