Geophysical Data Processing - Fourier analysis

Spectral analysis (using Fourier Transformation): is a mathematical technique that decompose any periodic complex waveform into a series of sine (or cosine) waves. By this spectral analysis, any periodic waveform can be transformed from the time domain (expressing wave amplitude as a function of time, or distance) to the frequency domain (expressing the amplitude and phase of its constituent waves as a function of frequency). References: 1- Kearey, P. , Brooks, M., Hill, I., 2002. An Introduction to Geophysical Exploration. Blackwell Science Ltd.