Nonuniformly sampled signal analysis for track irregularity

Current spectral analysis for track irregularity is based on sampling data in uniform intervals,but a train has fluctuating velocity,therefore,the accuracy of the traditional spectral analysis is in doubt.A nonuniformly sampled sequence was studied to set up the power spectral density(PSD) formula of an nonuniformly sampled signal.The new formula was used to analyze the nonuniformly sampled cases when the sampling interval was Gaussian distribution.The results showed that the PSD formula of a nonuniformly sampled signal includes the classic uniformly sampled signal's PSD formula,it verifies the accuracy of the new formula.Finally a method was put forward to measure the probability density function of the sampling interval for track irregularity spectral analysis.