A system is provided for resolving ambiguity in a phase measurement used in a distance estimation for an object. The system includes a transmitter for transmitting RF signals from an object location. The system includes measurement equipment for receiving the transmitted RF signals as corresponding received RF signals and measuring a plurality of phases at different frequencies between the transmitted RF signals and the corresponding received RF signals. The system includes a processor. The processor is configured to calculate normalized phases from the plurality of measured phases. The processor is configured to perform an intra-frequency ambiguity resolution process that resolves an ambiguity for the normalized phases for a single frequency using an ambiguity factor. The processor is configured to perform an inter-frequency ambiguity resolution process that resolves an ambiguity for the normalized phases across multiple tones using a characteristic curve to provide a resolved phase measurement for the distance estimation.