Walsh’s generalized function method has illuminated its concision and distinction in the description of the Bragg scatter mechanism and been well accepted around the world in the field of High Frequency(HF) electromagnetic wave scattering over the ocean surface. The foundation theory of the generalized function method is outlined. The first-and second-order HF radar cross sections are depicted with monostatic and bistatic operations, along with the pulsed and Frequency Modulated Continuous Wave(FMCW) radar waveforms. Some front edge results are discussed, such as the statistical properties of the first-order Bragg fluctuations with their possible applications and superiority in solving the practical problems. The prospect of further research and development is pointed out as well.