IDENTIFICATION OF ACCELEROMETERS BY SHOCK PULSE EXCITATION (PART 2)

The first part of this study described the test signals and the signal processing scheme for determining the dynamic behaviour of accelerome ters by shock excitation and laser interferometry. This second part is concerned with the analysis of the signal processing steps providing peak value and spectrum of shock-shaped acceleration signals. After di gitalization of the phase-modulated signals at the output of a homodyn e or heterodyne interferometer, the time-dependent displacement is rec onstructed based on the principle of coherent demodulation. The signal processing steps proposed for determining peak value and spectrum of the acceleration signal can be adapted to typical shock pulse shapes. They ensure an efficient suppression of deterministic and stochastic d isturbing quantities. Computer simulations and experimental investigat ions also proved that the peak value and the spectral components of sh ock-shaped accelerations can be measured with expanded uncertainties o f less than 0,2%.