A method for determining a FDOA of a pulsed waveform received by two sensors includes obtaining a respective plurality of in-phase and quadrature-phase (IQ) samples indicative of a pulse envelope of the received pulsed waveform. The method includes determining a TDOA responsive to a leading edge of a pulse of the pulsed waveform and obtaining a first cross correlation of IQ samples at a delay (dc) closest to the TDOA, and respective second and third cross correlations at least one additional delay (dc+1 and dc−1) on either side of the closest delay. The method includes refining the approximation of the TDOA according to an interpolation of amplitudes of the cross-correlation and determining a respective rate of change of cross-correlation phase (Δφ). The method includes approximating a straight line fit to the rates of change of cross-correlation phase (dΔφ/dt), the slope of the straight line representative of the FDOA.