Classification of Buried Targets Using Time-Frequency Signatures Extracted by a Ground Penetrating Radar
It is gaining acceptance by the radar signature community that effective target recognition requires more advanced signal analysis methods than those available for the frequency or time domains, separately. In recent years, the various distributions in the time-frequency domain of the Wigner-type, or Cohen class1–3 have proven their feasibility of extracting features in the cross-section of returned echoes and be more informative by their ability to display the time evolution of these features. As we demonstrated earlier, resonance features generated in the time-frequency domain from an echo backscattered by a target in free space,4–6 or buried underground,7 when a pulse from an impulse radar is incident on it, could be used to identify the target. A precondition in these time-frequency analyses is that the broad-band pulses emitted by the impulse radar do not exhibit distorting anomalies in their spectra. These anomalies could detrimentally affect the extracted resonance features in the time-frequency distribution of the pulses backscattered by any target.
KeywordsCluster Center Ground Penetrate Radar Wigner Distribution Cluster Plot Antenna Unit
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