Scattering Measurements from a Buried Object Using an Acoustic Parametric Source

This paper briefly describe an experimental work which aims at using an acoustic parametric source to detect buried objects. A broadband (150~250 kHz) transducer is used as a parametric source and transmitting primary frequency signals with CW and LFM envelope at various pulse lengths and bandwidths. Scattering measurements from a buried metal disk of 15cm diameter is implemented in a test tank of size 1m×0.7m×1m. The results show that the acoustic response between the watersediment interface and the buried disk can be distinguished clearly in the time domain by transmitting a broadband (5~35 kHz) difference frequency LFM signal without envelope correction, and the reverberation signal is weak due to narrow beam of the parametric source.