Fitting FFT-derived spectra: Theory, tool, and application to solar radio spike decomposition

Journal Article · Thu Jul 10 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/789/2/152· OSTI ID:22365688

Nita, Gelu M.; Fleishman, Gregory D.; Gary, Dale E. ^[1]; Marin, William ^[2]; Boone, Kristine ^[3]

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1. Center For Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States)
2. Binghamton University, Vestal, NY 13850 (United States)
3. University of Calgary, Calgary, AB T2N 1N4 (Canada)

Spectra derived from fast Fourier transform (FFT) analysis of time-domain data intrinsically contain statistical fluctuations whose distribution depends on the number of accumulated spectra contributing to a measurement. The tail of this distribution, which is essential for separating the true signal from the statistical fluctuations, deviates noticeably from the normal distribution for a finite number of accumulations. In this paper, we develop a theory to properly account for the statistical fluctuations when fitting a model to a given accumulated spectrum. The method is implemented in software for the purpose of automatically fitting a large body of such FFT-derived spectra. We apply this tool to analyze a portion of a dense cluster of spikes recorded by our FASR Subsystem Testbed instrument during a record-breaking event that occurred on 2006 December 6. The outcome of this analysis is briefly discussed.

• OSTI ID: 22365688
• Journal Information: Astrophysical Journal, Vol. 789, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
DATA ANALYSIS
DECOMPOSITION
DISTRIBUTION
FLUCTUATIONS
FOURIER TRANSFORMATION
SPECTRA
SUN