2D Angle Estimation in Planar Arrays Using Unitary-ESPRIT Algorithm: MATLAB Implementation

In this article, we explore a crucial topic in planar array signal processing: two-dimensional angle estimation. Specifically, we introduce the Unitary-ESPRIT algorithm for 2D angle estimation and provide a corresponding MATLAB implementation. This algorithm offers high precision and computational efficiency, making it widely applicable in signal processing applications. The MATLAB code demonstrates how to implement the Unitary-ESPRIT algorithm with detailed comments and explanations. Key implementation aspects include: - Matrix construction for signal subspace estimation using real-valued computations - Efficient eigenvalue decomposition through unitary transformation - Automatic pairing of elevation and azimuth angles using rotational invariance properties - Built-in normalization and scaling procedures for accurate angle extraction The program showcases core functions like unitary transformation matrix generation, signal covariance estimation, and subspace tracking. We discuss the algorithm's limitations regarding snapshot requirements and coherence sensitivity, along with potential improvements such as forward-backward averaging and spatial smoothing techniques. Practical optimization strategies for real-world applications are also covered. Through this study, readers will gain deeper insights into 2D angle estimation in planar array signal processing and learn how to effectively implement the Unitary-ESPRIT algorithm in MATLAB environments.