نتایج جستجو برای: مدل sar

تعداد نتایج: 137488  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد 1388

یکی از مسائلی که در سیستم sar مطرح می شود مسأله نویز speckle می باشد. منبع تولید نویز speckle فاز نسبی پراکنده گرهای مختلف در یک سلول رادار می باشد که نوسانات شدیدی در سیگنال دریافتی به وجود آورده و تصویر حاصل را دانه دانه می نماید. این نویز تفسیر تصاویر را مشکل و اطلاعات زیادی را مخفی می کند و لذا کاهش آن یکی از ملزومات در پردازش سیگنال sar است. الگوریتمهای متعددی جهت کاهش نویز speckle در نوا...

Journal: :Remote Sensing 2016
Shengli Song Bin Xu Jian Yang

Automatic target recognition (ATR) in synthetic aperture radar (SAR) images plays an important role in both national defense and civil applications. Although many methods have been proposed, SAR ATR is still very challenging due to the complex application environment. Feature extraction and classification are key points in SAR ATR. In this paper, we first design a novel feature, which is a hist...

2010
Jean-Marc Le Caillec René Garello Bertrand Chapron

In this paper, the synthetic aperture radar (SAR) process of Hie ocean surface mapping is studied using a decomposition based on a Volterra model. By a mathematical expansion of the complex exponential of the complete SAR transform, these models decompose the nonlinear distortion mechanisms of the SAR spectrum over different spectra of polynomial interactions. Thus, they offer an alternative mo...

Homayouni, Saeid, Farhadiani, Ramin , Safari , Abdolreza ,

Speckle is a granular noise-like phenomenon which appears in Synthetic Aperture Radar (SAR) images due to coherent properties of SAR systems. The presence of speckle complicates both human and automatic analysis of SAR images. As a result, speckle reduction is an important preprocessing step for many SAR remote sensing applications. Speckle reduction can be made through multi-looking during the...

2014
Craig Stringham David G. Long

Unmanned air systems (UAS) provide an excellent platform for synthetic aperture radar (SAR), enabling surveillance and research over areas too difficult, dangerous, or costly to reach using manned aircraft. However, the nimble nature of the small UAS makes them more susceptible to external forces, thus requiring significant motion compensation in order for SAR images to focus properly. SAR back...

Journal: :رادار 0
علیرضا ابراهیمی نیا محمد صادق هل فروش حبیب اله دانیالی

sar (synthetic aperture radar) image enhancement and segmentation is purpose of this thesis. sar image segmentation is a primary step before steps such as classification and target recognition. the main obstacle in sar image segmentation is inherent speckle noise. speckle noise is a multiplicative and highly destructive noise which results to intensity inhomogeneity. hence common segmentation m...

Journal: : 2022

با توجه به رشد بالای جمعیت در جهان و نیاز اطمینان از امنیت غذایی، افزایش تولید واحد سطح محصولات زراعی به‌منزلة راهبردی اساسی حل مسئلة تأمین غذا به‌شمار می‌رود. سوی دیگر، وجود محدودیت زیرکشت پایین‌بودن میانگین عملکرد برخی کشاورزی مانند گندم کشور، محصول می‌تواند راهکاری عملی پاسخ کشور محسوب شود. یکی مهم‌ترین بیماری‌های فوزاریوم است که، نقش پیش‌بینی این بیماری جلوگیری کاهش بهره‌وری محصول، مدل‌هایی...

Journal: :Journal of Multimedia 2014
Xiao-hua Wang Ka-zhong Deng Hua-chao Yang

The accurate Synthetic Aperture Radar (SAR) image registration is important for exact analyses of mine deformation and ecological environment change. Currently, many image registration algorithms have been proposed, but these registration algorithms cannot be directly applied to SAR image, so an integrated registration approach is presented in this paper. Firstly, it is the coarse matching with...

2005
E. E. SANO A. R. HUETE

In this study, we investigated the feasibility of using the C-band European Remote Sensing Satellite (ERS-1) synthetic aperture radar (SAR) data to estimate surface soil roughness in a semiarid rangeland. Radar backscattering coefficients were extracted from a dry and a wet season SAR image and were compared with 47 in situ soil roughness measurements obtained in the rocky soils of the Walnut G...

2009
Moon-Kyung Kang Kwang-Eun Kim Hoonyol Lee Seong-Jun Cho Jae-Hee Lee

Ground-Based SAR system that obtains a high resolution 2D image on the ground is a new type of SAR system such as air-borne and space-borne SAR. The measured fully polarimetric SAR images with HH, HV, VH, and VV were focused using the Deramp-FFT (DF) algorithm in terms of their image formation principles. SAR polarimetry technique is concerned with control of the polarimetric properties of rada...

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