Frequency difference of arrival accuracy

The problem considered occurs in the geolocation of a fixed emitter using observations from two moving collectors. Estimates for the time difference and frequency difference of signal arrivals are used. Frequency difference of arrival (FDOA) is estimated through the use of a mixing product. Standard regression analysis procedures are then applied to estimate the slope of the unwrapped phase angle. The derivation of an expression for the standard error of FDOA is given, and this result is related to several other well-known results.<>