Compensation Method for the Estimation of the Autospectral Density Function of the Unevenly Spaced HIFiRE-1 Flight Data (Postprint)
AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AEROSPACE SYSTEMS DIR
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The time series data collected during the HIFiRE-1 flight experiment was sampled unevenly due to telemetry dropouts and the sampling scheme selected. Sampling unevenly results in frequency translation of power to artificial sidelobes. These sidelobes distort the real and imaginary components of the Fourier transform such that the spectrum of the sampled data no longer represents the spectrum of the physical process generating the data. These sidelobes can be eliminated by resampling the data onto an evenly spaced grid at the cost of under predicting the power of the higher frequency components in the data. In this paper, a compensation procedure is developed to recover the power loss caused by resampling. This compensation procedure is suitable for stochastic time series data having red-noise spectra such as the pressure fluctuations recorded underneath laminar and turbulent boundary layers.
- Military Aircraft Operations