Abstract: Systems and methods are provided for locating underground utility equipment. In an exemplary embodiment, the local utility power grid frequency is detected using a bandwidth filter centered around the nominal or expected frequency, for example, 60 Hz in the US, or 50 Hz in Europe. From the actual utility power grid frequency detected, the frequency of one or more harmonics of the detected power grid frequency are calculated, and then the calculated value(s) may be used to tune one or more bandwidth filters, or to further refine a power grid frequency offset enabling detection of a larger range of frequencies. Using the offset, any detected power grid frequencies and desired harmonics may be used by a utility locator or system to increase detection and location accuracy by adjusting for any power grid frequency fluctuations.