Research Article

Bioinspired Low-Frequency Material Characterisation

Figure 6

Frequency domain spectra for the 40 mm thick polyvinylchloride (PVC) target obtained using the zero phase ladder (ZPH) chirp (grey) and linear frequency modulated (LFM) chirp signal (black).
927903.fig.006a
(a) transmission spectra
927903.fig.006b
(b) pulse echo spectra