Practical seismic waveforms are finite and have limited bandwidth. They are the summation of discrete sinusoids, each with its own amplitude, frequency, and phase characteristics.
A band-limited wavelet and its component sinusoids is shown below,
A bandlimited signal cannot be also timelimited. More precisely, a function and its Fourier transform cannot both have finite support unless it is identically zero.
Zero phase
When the wavelet is symmetric about t = 0, it is referred to as a zero-phase wavelet, each of its component sinusoids is zero phase, and each is uniquely defined by its own amplitude and frequency.
