Theory

I will first present the far-field reciprocity equations of correlation and convolution types, and then show how they can be used to construct super-virtual diffractions. The use of the far-field reciprocity equations of correlation and convolution types to create virtual diffractions and enhance their SNR is similar to that of Mallinson et al. (2011), except diffraction energy is enhanced rather than refraction energy. I will assume an acoustic medium with an arbitrary velocity distribution with constant density, and wideband sources with unity amplitude at each frequency.