UAV navigation system using Global Positioning System (GPS) is very vulnerable due to malicious at-tacks such as jamming and spoofing. The GPS receiver receives the electromagnetic waves from more than 24 satellites outside the atmosphere and determines its position. However, since GPS signals are received from satellites 20,000 kilometers away, the power of the signal is very weak.
One of the most effective way to eliminate malicious interference signals is to use an array antenna in GPS receiver. Capon and Multiple Signal Classification (MUSIC) algorithms are commonly used to estimate the direction of the incident signal, i.e., direction of arrival (DOA) estimation algorithm. The MUSIC algo-rithm is superior to the DOA estimation, but resolution between the desired signal and adjacent signals is low and the computational complexity is high. Therefore, in this paper, we can localize the candidate angle of the MUSIC algorithm by using the angular velocity and acceleration measurement of the inertial measurement unit (IMU), and accurately estimate the DOA and reduce the complexity.