New method for estimation of nuclear quadrupole resonance signals parameters in multi-block

Aiming at the time-variation characteristic of interference signals in the explosive detection using the nuclear quadrupole resonance (NQR) technique, and according to the real world signal model of each signal sample block including the fixed NQR signal, time-variation interference signals and noise, an improved multi-block hankel total least squares stack (HTLSstack) method is presented. Firstly, the number of common poles is determined using the HTLS scheme; secondly, a new selection criterion is constructed to choose the common poles; finally, the prior knowledge is employed to realize the estimation of NQR signals effectively. This method makes full use of the information on original data, and in the case of a low signal-to-noise ratio, it can avoid the performance loss of the multi-block HTLS method in the first singular value decomposition (SVD). The validity of this algorithm is demonstrated with the results of both simulated data and experimental data.