Chinese Journal of Magnetic Resonance ›› 2012, Vol. 29 ›› Issue (3): 393-400.

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An Improved Detection Algorithm for Detection of Weak NQR Signals

 ZHU Kai-Ran*, Wu Hui-Yang, ZHENG Ji-Bin, SU Tao   

  1. National Lab of Radar Signal Processing, Xidian University, Xi′an 710071, China
  • Received:2011-11-21 Revised:2012-03-20 Online:2012-09-05 Published:2012-09-05
  • Supported by:

    国家自然科学基金青年科学基金资助项目(61001204), 中央高校基本科研业务费专项资金资助项目(JY0000902020), 陕西省“13115”科技创新工程资助项目(2009ZDKG-26).

Abstract:

Nuclear quadrupole resonance (NQR) is a solid-state radio frequency (RF) spectroscopic technique allowing the detection of many high explosives. However, the NQR signals are intrinsically weak, and the practical use of NQR is hindered by low signal-to-noise ratio (SNR), and artifacts arising from the thermal noise of the coil and external radio frequency interference (RFI). In this paper, we described an improved detection algorithm for detection of weak NQR signals. First, singular value decomposition using the Hankel matrix was utilized to restrain RFI and filter noise. A non-linear least squares detector based on the (multiple signal classification) MUSIC spectral estimation was applied, which not only guaranteed a high resolution in the frequency domain, but also led to significant reduction in the amount of computation. The effectiveness of this algorithm was demonstrated with the simulated and experimental results.

Key words: nuclear quadrupole resonance (NQR), non-linear least squares detector, MUSIC, singular value decomposition (SVD)

CLC Number: