Journal of Astronautics ›› 2014, Vol. 35 ›› Issue (8): 931-937.doi: 10.3873/j.issn.1000-1328.2014.08.010

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A Constant False Alarm Rate Detection Algorithm for X ray Pulsar Signal Based on S transform

WANG Lu,  XU Lu ping,  ZHANG Hua   

  1. School of Electronic Engineering,Xidian University,Xi’an  710071,China
  • Received:2013-08-09 Revised:2014-03-14 Online:2014-08-15 Published:2014-08-25

Abstract:

In order to overcome shortcomings of traditional X ray pulsar signal detection algorithm,such as large computing, poor detection performance in low signal to noise ratio (SNR), etc, a novel constant false alarm rate (CFAR) detection algorithm is proposed based on S transform (ST). Firstly, threshold filtering is operated on the S transform power spectrum of cumulative signal according to distribution character of S transform power spectrum of Gaussian white noise. Then the sum of the time frequency power spectrum after threshold filtering is used as a test statistic and its distribution characteristic is analyzed theoretically. It is concluded that the test statistic obeys Gaussian distribution, which is also verified by Monte Carle method. And on this basis, the probability density function (pdf) of the test statistic is used to calculate the decision threshold so as to realize the CFAR detection. Theoretical analysis and simulation results indicate that the proposed method has better detection accuracy than a similar CFAR detection algorithm based on the Gaussian distribution, and it also has lower complexity.

Key words: X ray pulsar, Detection, S transform, False alarm probability, Chi square distribution

CLC Number: