Methods and systems for hierarchical de-aliasing time-of-flight (tof) systems

A TOF system acquires depth data using n = 3 modulation frequencies f 1, f 2,..., f m separately, associated with separate aliasing interval ranges Z 1, Z 2,...Z m . Next, n intermediate frequencies f DE 1,f DE 2,...f DEn are generated sorted by order of f DE 1 f DE 2 ...f DEn and corresponding phases are computed from the data acquired separately using f 1, f 2,..., f m . Hierarchically dealiasing of the thus-acquired data is carried out using the generated intermediate frequencies. Thus operated, the TOF system provides an effective aliasing interval range Z D > Z k for k = 1n as if said TOF system operated at a very low modulation frequency f D , while simultaneously providing depth resolution certainty as if said TOF system operated at a high modulation frequency f E . Preferably high modulation frequency f E is a function of all modulation frequencies f 1, f 2,..., f m , which function may be an arithmetic mean or a weighted average of f 1, f 2,..., f m .