Document Details

Document Type : Thesis 
Document Title :
ISAR IMAGING OF SMALL MARINE TARGETS USING JOINT TIME-FREQUENCY TRANSFORMS
مصاورة رادار الفوهة المُركبة العكسي للأهداف البحرية الصغيرة باستخدام التحويلات الزمنية-الترددية المشتركة
 
Subject : Faculty of Engineering - Department of Electrical and Computer Engineering 
Document Language : Arabic 
Abstract : Inverse Synthetic Aperture Radar (ISAR) imaging is the process of resolving a set of the target complex valued radar illuminations into a high resolution 2D target image. The target motion is composed of: translational and rotational motions. Rang Alignment is used to align successive received target echoes to limit the motion information of the target into only that of the rotational motion. If the rotation is with constant angular velocity, then the Fourier transform along the cross-range, Doppler, dimension will result in a high resolution image. However, small marine targets are characterized by their complex and unpredicted rotational motion which will degrade the Doppler resolution by introducing high order differential terms to the phase information of the target. Range Instantaneous Doppler (RID) imaging, rather than Range Doppler, is used to compensate these phase errors using Joint Time-Frequency Transforms (JTFTs). In this thesis, the Wavelet Fit algorithm is proposed as a range alignment algorithm and is perceived after detailed discussion of the aligning errors that induce when using envelope similarity range alignment methods. The Wavelet Fit algorithm is implemented on measured data and is compared with the Global Rang Alignment algorithm, and the correlation algorithm. The compared algorithms performed numerically close, where the Wavelet Fit algorithm had competitive performance and visual advantage. RID imaging is discussed after the introduction of JTFTs, beginning from the STFT, and ending by the S-distribution. The challenge of utilizing the S-distribution as an RID imaging technique is encountered by developing the Modified S-method (MS-method), which is discussed and applied on modeled; simulated; and measured data. The validity of the MS-method was indicated by outputting high-resolution images. 
Supervisor : Dr. Ahmed Balamesh 
Thesis Type : Master Thesis 
Publishing Year : 1434 AH
2013 AD 
Added Date : Saturday, March 30, 2013 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
طارق محمد وزنـهWAZNA, TARIQ MOHAMEDResearcherMaster 

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