Two-dimensional waveform is formed by the scattered signals (photons) (see Figure 1). This is a key point to investigate geologic and tectonic structure and texture of soil and sea surface. However, the waveform actually presents three-dimensional shape. It has density of signals for each unit volume element. Showing it in two-dimensional form is only for conveniently defining some parameters for it. Its general mathematical expression is to be given in later section. According to practice, many unknown phenomena can be discovered from this wave form. Some relevant and useful parameters are listed in Table 1.