Honoring Akira Ishimaru's contributions to waves in random media: editorial

To honor the work and career of Akira Ishimaru, we discuss three topics in waves in random media where he has made important contributions: radiative transfer, backscattering enhancement, and time reversal. These three topics represent only a small sample of the entirety of Ishimaru's research contributions. Nonetheless, they offer a concrete picture of the substance and quality of his original research and point to the legacy of his long career.