generating radar data based on a radar transmission signal transmitted through an array antenna of a radar sensor based on a frequency modulation model and a radar reception signal received through the array antenna as the radar transmission signal is reflected by a target;

correcting the radar data using a correction vector derived from radar data corresponding to the direction of arrival of 0 degrees by removing a feedline delay difference between channels of the array antenna for correcting a feedline error occurring due to the feedline delay difference between the channels of the array antenna according to difference in arrival time of the radar transmission signal from a power divider to each transmission antenna element in the array antenna due to physical factors between the power divider and the transmission antenna elements;

estimating an initial direction of arrival corresponding to the corrected radar data using a direction matrix reflecting a phase shift of the corrected radar data according to frequency modulation characteristics of the frequency modulation model; and

estimating a final direction of arrival corresponding to the corrected radar data by removing, using an element beam pattern (EBP) model, an EBP error in the initial direction of arrival, the EBP error occurring due to an influence of a beam pattern of an antenna element in the array antenna on a beam pattern of the array antenna,

wherein the EBP error model is configured to represent EBP error values for each angle, and

wherein the EBP error model is generated by estimating EBP error values for other angles based on EBP error values for base angles pre-measured through tests.