“…Since the pioneering work of Marshall and Palmer [1948] on the rain DSDs, most of those which followed, such as [Atlas et al, 1999, Cerro et al, 1997, Chen et al, 2019, Tenorio et al, 2012, Tokay and Short, 1996, Uijlenhoet et al, 2003, Ulbrich, 1983, Ulbrich and Atlas, 1998, Wen et al, 2018, Willis, 1984, Zeng et al, 2019, Zhang et al, 2003etc. ], analyse it with N (D) function, defined by spectrum of a given period T (1 min).…”