The echo amplitude
is measured on the graph's horizontal axis, and depth is registered on the vertical axis.
19] uses fractional Brown motion to model echo amplitude
fluctuation, on this basis, puts forward a classification method based on fractional Brown fractal dimension of echo in time and frequency domain (CMFBFD) for low-resolution radars, and gains a better classification effect for helicopters and civil aircrafts using the proposed method.
For the visualization and mapping we applied three signal processing algorithms: signal demodulation for echo amplitude mapping; short time Fourier transform (STFT) based algorithms for mapping of mean instantaneous frequency (MIF) and mean instantaneous bandwidth (MIB) of raw echosignal spectrum.
The isolines on the echo amplitude map are drown at levels from -34 dB to -46 dB in -3 dB intervals.
The echo amplitude was further integrated between TOT = 16.
Consequently, delamination or nonbonding in the seal causes a greater reflected echo amplitude to return to the transducer because of the higher acoustic-impedance difference between the discontinuous region in the seal and the polymeric package material.
In time domain imaging, where the echo amplitudes
are recorded at a particular depth, solid-to-gas interfaces stand out in the monochrome acoustic image because they are white, and are typically much brighter than solid-to-solid interfaces, which typically reflect 20% to 80% of the ultrasound and are gray.