Radio frequency interference suppression for landmine detection by quadrupole resonance

Abstract

The quadrupole resonance (QR) technology can be used asa confirming sensor for buried plastic landmine detection bydetecting the explosives within the mine. We focus herein onthe detection of TNT mines via the QR sensor. Since the frequency of theQR signal is located within the AM radio frequency band, the QRsignal can be corrupted by strong radio frequency interferences(RFIs). Hence to detect the very weak QR signal, RFI mitigation isessential. Reference antennas, which receive RFIs only, can beused together with the main antenna, which receives both the QRsignal and the RFIs, for RFI mitigation. The RFIs areusually colored both spatially and temporally, and henceexploiting only the spatial diversity of the antenna array may notgive the best performance. We exploit herein both the spatial andtemporal correlations of the RFIs to improve the TNT detectionperformance.