An Integrated Direction-Finding Method Based on L1-Norm Correlation Interferometer and MUSIC Algorithm

Direction finding of radiation sources is one of the key technologies for space situational awareness. High accuracy and real-time performance of direction-finding systems are of great significance in the rapidly changing electromagnetic battlefield. Traditional correlative interferometer algorithms are simple in implementation but suffer from low elevation resolution and insufficient accuracy, while the MUSIC algorithm achieves high precision at the cost of high computational complexity, resulting in poor real-time performance.To address these issues, this paper proposes and implements an integrated direction-finding method combining an L1-norm-based correlative interferometer and the MUSIC algorithm. First, at the algorithmic level, an improved correlation coefficient based on the L1 norm is introduced to replace the nonlinear similarity computation in the traditional correlative interferometer. This approach maintains sensitivity to elevation angles while simplifying trigonometric operations into hardware-friendly basic arithmetic, thereby reducing the design complexity on FPGA. Second, at the system architecture level, an integrated processing framework of “interferometer coarse estimation – MUSIC fine estimation” is constructed. The coarse estimation results from the interferometer serve as prior information for the MUSIC algorithm, constraining the spectral peak search within a small local neighborhood. Finally, comparative analysis between MATLAB simulations and FPGA computation results demonstrates that the relative errors between the fixed-point FPGA implementation and floating-point MATLAB computation of all core modules remain below the order of 1.0×10⁻⁶. While ensuring accuracy, the proposed method reduces direction-finding time by 98% compared with the full-space search of the pure MUSIC algorithm, thus verifying the effectiveness, real-time capability, and high precision of the proposed approach. This work provides a technical foundation for the development of next-generation high-performance, low-power satellite-borne electronic reconnaissance and situational awareness systems.