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Open Access

Instantaneous Spectrum Estimation from Event-Based Densities

  • Lorenzo Galleani1Email author,
  • Leon Cohen2,
  • Douglas Nelson3 and
  • Jeffrey D. Scargle4
EURASIP Journal on Advances in Signal Processing20022002:180621

Received: 31 July 2001

Published: 14 January 2002


We present a method for obtaining a time-varying spectrum that is particularly suited when the data are in event-based form. This form arises in many areas of science and engineering, and especially in astronomy, where one has photon counting detectors. The method presented consists of three procedures. First, estimating the density using the kernel method; second, highpass filtering the manifestly positive density; finally, obtaining the time-frequency distribution with a modified Welch′s method. For the sake of validation event-based data are generated from a given distribution and the proposed method is used to construct the time-frequency spectrum and is compared to the original density. The results demonstrate the effectiveness of the method.


time-frequency analysisdensity estimationkernel method

Authors’ Affiliations

Dipartimento di Elettronica, Politecnico di Torino, Torino, Italy
City University of New York, New York, USA
US Department of Defense, Fort Meade, USA
Space Science Division, NASA Ames Research Center, Moffett Field, USA


© Galleani et al. 2002