# Robust adaptive beamforming based on covariance matrix reconstruction with annular uncertainty set constraints

## TL;DR

This paper introduces a new beamforming method that improves performance in flexible arrays by addressing covariance and steering vector mismatches.

## Contribution

The novelty lies in reconstructing the covariance matrix and correcting the steering vector under annular uncertainty set constraints.

## Key findings

- The method reduces mismatch impact in flexible arrays.
- Performance improved by 4–10 dB in simulations and sea trials.
- Robustness of adaptive beamforming is significantly enhanced.

## Abstract

A robust adaptive beamforming method based on the interference covariance matrix reconstruction with annular uncertainty set constraints is proposed to address the issues of covariance matrix mismatch and steering vector mismatch caused by the distortion of flexible array shapes. The proposed method first eliminates the target components under the constraint of the annular uncertainty set to accurately re-construct the covariance matrix, and then corrects the steering vector using a constrained optimization method. This effectively reduces the impact of mismatch and significantly enhances the performance of the adaptive beamforming algorithm with array distortion, improving the robustness of the adaptive beamforming algorithm for flexible arrays. Simulation and sea trial data validate that the new method achieves a performance improvement of 4–10 dB.