Extended Nested Arrays for Consecutive Virtual Aperture Enhancement

In this letter, we propose an extended nested array (ENA) strategy, which relaxes the constraints on the two-side subarrays of the augmented nested array and allows the sensors further placed from the sparse uniform linear array. To guarantee the continuity of the difference co-array (DCA), several conditions are provided for specific design. Based on these rules, two ENAs, referred to as one-side extended nested array (OS-ENA) and two-side extended nested array (TS-ENA), are developed. The DCAs of both the OS-ENA and TS-ENA are hole-free and possess more consecutive lags than the existing nested-like arrays. Simulations verify the superiorities of the proposed ENAs with the spacial smoothing MUSIC algorithm used.