Multi‐Target Direct Position Determination Method for Mobile Single Station Based on Second‐Order Difference Co‐Array

ABSTRACT

This paper proposes a multitarget direct position determination method for mobile monostatic stations based on the second‐order difference coprime array. Leveraging the direct position determination model of the mobile monostatic station with coprime arrays, this method fully exploits the virtual aperture extension characteristics of coprime arrays and constructs a second‐order difference co‐array via the redundant data averaging technique to attain a larger equivalent array aperture. After conducting hole zero‐interpolation preprocessing, the spatial smoothing technique is integrated to restore the full‐rank property of the covariance matrix. Subsequently, the alternating direction method of multipliers (ADMM) based on the minimisation of the ratio minimisation of nuclear norm to Frobenius norm is introduced to address the hole‐filling challenge of virtual arrays. Finally, by utilising the spatial diversity characteristics of the mobile platform, a subspace data fusion algorithm is adopted to realise high‐precision localisation of multiple radiation sources. Simulation results demonstrate that the proposed method can effectively localise multiple radiation sources even under the conditions of low signal‐to‐noise ratio (SNR) and limited observation data. Compared with the traditional first‐order difference co‐array method, the proposed method achieves a significant reduction in localisation error, whilst exhibiting excellent resolution and degree of freedom (DOF) performance.