آشکارسازی همدوس سيگنال راداری با شيفت داپلر نامعلوم در كلاتر غير گوسی
محورهای موضوعی : مهندسی برق و کامپیوترمحمدرضا تابان 1 , عبدالرضا محمدي 2 , سیدمحمود مدرس هاشمی 3
1 - دانشگاه يزد
2 - دانشگاه یزد
3 - دانشگاه صنعتی اصفهان
کلید واژه: آشكارسازي رادارشيفت داپلر نامعلومكلاتر غيرگوسيهمدوس,
چکیده مقاله :
در اين مقاله آزمون فرضيه مرکب برای آشکارسازی همدوس سيگنال راداری با تموج آهسته و شيفت داپلر نامعلوم در کلاتر غير گوسی حل شده است. به آشکارسازی همدوس سيگنال راداری با شيفت داپلر نامعلوم در معدود كارهاي تحقيقاتي و آن هم با فرض كلاتر گوسی توجه شده است. در رادارهاي امروزي كه داراي تفکيک‌پذيری بالا هستند و در زواياي ميل کم، توزيع‌های شبه‌گوسی به صورت مناسب‌تری بر توزيع آماری كلاتر منطبق می‌شوند. از آنجايی که آشکارسازي بهينه هدف با شيفت داپلر نامعلوم در كلاتر شبه‌گوسی شامل يک انتگرال چندگانه پيچيده است، لذا در اين مقاله آشکارسازهای شناخته‌شده و شبه‌بهينه GLR و CGLR معرفی شده و براي اولين بار تحت شرايط جديد تعميم داده مي‌شوند. همچنين با استفاده از تخمين متغير تصادفي منصوب به توان کلاتر (τ) در سلول تحت آزمايش، آشکارساز GLRTLQ معرفي شده و براي حالت شيفت داپلر نامعلوم تعميم داده مي‌شود. خواهيم ديد اين آشکارساز ساختاری ساده و مستقل از توزيع کلاتر داشته و در نتيجه CFAR مي‌باشد. در ادامه با انجام شبيه‌سازي كامپيوتري عملکرد آشکارسازهای پيشنهادي بررسی شده و مورد ارزيابي قرار مي گيرد.
In this paper the problem of detection of coherent radar signals with slow fluctuating amplitude and unknown Doppler shift in non-Gaussian clutter is considered. Coherent radar signal detection with unknown Doppler shift is rarely considered in the literature. It has been demonstrated that in high resolution radars or in small grazing angles, the pseudo-Gaussian models are more accurate than Gaussian for clutter modeling. Optimum detection of signals with unknown Doppler shift in pseudo-Gaussian clutter contains a complicated multiple integral. Therefore, in this paper, generalized forms of the suboptimum GLR and CGLR detectors are proposed. Also, by estimating the random variable related to the clutter power (τ) in the test cell, GLRTLQ detector for unknown Doppler shift case is introduced and generalized. It is demonstrated that the proposed GLRTLQ detector has a simple structure and does not depend on the clutter distribution. The performances of the proposed detectors are evaluated by computer simulation.
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