شکل‌دهی بهینه پرتو در رادار روزنه مصنوعی چرخشی زمین‌پایه به منظور بیشینه نمودن نسبت سیگنال به نویز در تصویر

نوع مقاله: مقاله پژوهشی

نویسنده

دانشگاه تحصیلات تکمیلی صنعتی و فناوری پیشرفته کرمان

چکیده

در این مقاله روشی برای شکل‌دهی پرتو دیجیتال بهینه در رادار روزنه مصنوعی چرخشی زمین‌پایه به­منظور بیشینه­شدن نسبت سیگنال به نویز (SNR) در تصویر ارائه گردیده است. در این روش با استفاده از یک آرایه از عناصر گیرنده، ضرایب مختلط وزن‌دهی کانال‌های مختلف گیرنده به­منظور بیشینه­شدن مقدار SNR با حل یک مسأله بهینه‌سازی و تجزیه مقادیر ویژه محاسبه می‌شود. مسأله بهینه‌سازی مذکور بر اساس مدل‌سازی داده در هر برد و تشکیل تصویر به روش فیلتر منطبق و محاسبه SNR در هر پیکسل تصویر بر حسب ضرایب وزن‌دهی کانال‌های گیرنده به­دست آمده و در نهایت ضرایب بهینه‌ هر برد به‌صورت بردار ویژه‌ متناظر با بزرگترین مقدار ویژه یک ماتریس حاصل از هندسه و پارامترهای سامانه ارائه گردیده است. شبیه‌سازی‌ها، برتری روش پیشنهادی در افزایش SNR تصویر –به­ویژه در بردهای دور- در مقایسه با شکل‌دهی پرتو به روش‌های دیگر شکل‌دهی پرتو دیجیتال را نشان می‌دهد.

کلیدواژه‌ها


عنوان مقاله [English]

Optimal Beamforming for Maximization of the Image SNR in Ground-Based Circular Synthetic Aperture Radar

نویسنده [English]

  • seyed rohollah Samare Hashemi
Graduate University of Advanced Technology
چکیده [English]

In this paper a method for optimal digital beamforming in ground-based circular synthetic aperture radar in order to maximize the image signal to noise ratio (SNR) is proposed. In this method to maximize the image SNR, an array of receiver elements is used and the complex weighting coefficients of receiver channels are computed by solving an optimization problem and eigenvalue decomposition. The optimization problem is formed based on data modeling in each range and matched filter image formation and SNR computation in each image pixel versus excitation coefficients. Finally, optimal weighting coefficients of each range are computed as the eigenvector corresponding to the largest eigenvalue of a matrix related to the geometry and parameters of the system. Simulations illustrate the superiority of the proposed method in increasing image SNR over other digital beamforming methods, especially at long ranges.    

کلیدواژه‌ها [English]

  • Synthetic Aperture Radar (SAR)
  • Circular Synthetic Aperture Radar (CSAR)
  • Digital Beamforming
  • Optimization
  • Eigenvalue Decomposition

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