New Ways to Visualize Time and Frequency Data
NAVAL OBSERVATORY WASHINGTON DC
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Some of the standards of numerical analysis in time and frequency are the formation of the various square roots of variances, such as Time Deviation TDEV, Allan Deviation ADEV, and Total Deviation TotDev, among others. As time and frequency measurements and transfer becomes better and better, especially at smaller sampling intervals, transient disturbances from such things as environmental perturbations become more and more important to characterize, locate, and understand. While developing software took to more fully analyze, visualize, and model time and frequency data, especially time transfer data, several new ways of looking at the data were tested for usefulness. One new way of looking at time-series data was first reported in 1987 and is called visual recurrence plots or analysis VRA l. VRA, the auto-correlation function A CF, power spectral density by the Barnes Digital Spectrum Analyzer method 2 PSD, periodogram using phase-dispersion-minimization techniques Jurkevich7 phase plane visualization PPV, time-frequency analysis TFA, and even 1-D wavelet decomposition of a time-series signal are being tested. This paper will show some recent results that show that all these numerical took are useful. Tests will be run on both real and synthetic data.
- Numerical Mathematics
- Computer Programming and Software