PROBLEM TO BE SOLVED: To provide a method for determining time difference of arrival (TDOA) and/or frequency difference of arrival (FDOA) to limit frequency and time period for examining presence of the signal to be located. SOLUTION: A method, used for locating a mobile transmitter, includes providing a set of cross-correlation values, wherein each cross-correlation value is associated with a corresponding value of the TDOA and/or FDOA estimate and is produced by cross-correlating a reference signal with a cooperating signal (Fig.5, not shown). The reference signal comprises a copy of a signal transmitted by the mobile transmitter as received at a first antenna and the cooperating signal comprises a copy of the same signal as received at a second antenna. The method further includes determining a most likely range of TDOA and/or FDOA estimates, and then identifying an optimal cross-correlation value within a subset (Fig.10) of cross-correlation values corresponding to the most likely range of TDOA and/or FDOA estimates. The TDOA and/or FDOA value corresponding to the optimal cross-correlation value is then employed for calculating the location of the mobile transmitter. COPYRIGHT: (C)2009,JPO&INPIT