Using the fast orthogonal search with first term reselection to find subharmonic terms in spectral analysis.
The fast orthogonal search (FOS) algorithm has been shown to accurately model various types of time series by implicitly creating a specialized orthogonal basis set to fit the desired time series. When the data contain periodic components, FOS can find frequencies with a resolution greater than the discrete Fourier transform (DFT) algorithm. Frequencies with less than one period in the record length, called subharmonic frequencies, and frequencies between the bins of a DFT, can be resolved. This paper considers the resolution of subharmonic frequencies using the FOS algorithm. A new criterion for determining the number of non-noise terms in the model is introduced. This new criterion does not assume the first model term fitted is a dc component as did the previous stopping criterion. An iterative FOS algorithm called FOS first-term reselection (FOS-FTR), is introduced. FOS-FTR reduces the mean-square error of the sinusoidal model and selects the subharmonic frequencies more accurately than does the unmodified FOS algorithm.
McGaughey
Donald R
DR
Royal Military College of Canada, Box 17000, Station Forces, Kingston, Ontario, Canada. mcgaughey-d@rmc.ca
Korenberg
Michael J
MJ
Adeney
Kathryn M
KM
Collins
Susan D
SD
Aitken
G J M
GJ
D000465:Algorithms; D003198:Computer Simulation; D004058:Diffusion; D005583:Fourier Analysis; D008954:Models, Biological; D009038:Motion; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013057:Spectrum Analysis / Q000379:methods; D013269:Stochastic Processes