1. A processor implemented method to hierarchically dealias distance Z range of a phase-type time of flight system having a processor, the method comprising: (a) acquiring data from said time of flight system using modulation frequencies f 1 , f 2 ,. .. , f m separately, wherein if said time of flight time of flight system were operated solely at one of said modulation frequencies, aliasing interval ranges of Z 1 , Z 2 ,. .. , Z m would result; (b) generating n intermediate frequencies f DE1 , f DE2 ,. .. , f DEn sorted by order of f DE1 <f DE2 <. .. <f DEn and computing their corresponding phases from data acquired at step (a); and (c) hierarchically dealiasing data acquired at step (a) using said intermediate frequencies generated at step (b); wherein said time of flight system provides an effective aliasing interval range Z D >Z k for k=1. .. n as if said time of flight system operated at a very low modulation frequency f D , while simultaneously providing depth resolution certainty as if said time of flight system operated at a high modulation frequency f E .