A calibration method and a system for providing calibration data for use with a direction finder are provided. The method comprises providing a relative motion of a calibration receiver in a circle manner with respect to calibration transmitter at a predetermined distance from each other. The method also includes preparing and transmitting a communication frequency signal employed for transmitting a certain frequency from a list of predetermined frequencies. The preparing comprises: (a) setting a value of the dwell time ranges of the communication frequency signal to a predetermined value; (b) synchronizing in time the dwell time ranges between the calibration transmitter and the calibration receiver by using clock signals of a common synchronization source; (c) providing a hop duration time interval within the dwell time range for transmitting the frequency; and (d) generating the communication frequency signal corresponding to the frequency during the hop duration interval. At the calibration receiver end, the method includes scanning the list of predetermined frequencies; intercepting a frequency signal transmitted during the hop duration time interval within the dwell time ranges; and rejecting all other frequency signals received within the dwell time ranges having duration different than the hop duration time interval by the receiver.