Introduces the key principles of signal theory and the application of sampling precision, frequency and signal reconstruction. Explores the characteristics of waveforms, line, phase and amplitude spectra, the minimum phase spectrum, sinusoid addition, generation of harmonics, the Fourier series and the Fourier integral. Outlines the characteristics of linear and nonlinear systems. Provides an overview of general operator responses, explores the concepts of superposition, convolution, integration, and differentiation and the mechanics of filter theory. Addresses the importance of the signal-to-noise ratio and how it can be improved, provides an explanation of the processes of filtering, stacking and deconvolution and the ideal situations when each process should be employed. Defines the correlation, cross-correlation and auto-correlation functions, the impulse response of a system, and the application of pulse compression to increase resolution and the signal-to-noise ratio.