Abstract
<title>Abstract</title> <p>Synthetic aperture optical systems achieve large-aperture resolution using multiple small sub-apertures, significantly reducing system volume, weight, and cost. Traditional annular, Golay-6, and Y-shaped arrays are classic sparse aperture configurations with excellent geometric symmetry and frequency-domain performance. However, existing studies lack systematic performance analysis of these typical structures under unified evaluation criteria. This paper proposes a comprehensive evaluation method based on four MTF metrics: angularly averaged MTF area, mid-frequency angular mean, worst-direction MTF area, and worst-direction mid-frequency mean. A total of 360 angular samples and 600 mid-frequency samples (0.2–0.8) are selected in polar coordinates. With a fixed circumscribed circle radius, all configurations share the same cutoff frequency, and their differences lie in MTF uniformity and mid-frequency capability. Results show that the annular structure has unstable mid-frequency response and local zeros, while the Y-shaped array outperforms others. Optimizing Golay-6 by adjusting inner sub-apertures yields an optimal Y-like configuration, confirming the inherent advantages of three-armed geometry. Further size optimization on the Y-shaped array delivers the best aperture structure. Finally, Simulations on 100 airplane images show that the optimized structure achieved an average PSNR of 28.33 dB and an average SSIM of 0.861, exceeding the best-performing traditional Y-shaped configuration by 0.53 dB and 0.019.</p>