نتایج جستجو برای: سیستم sar

تعداد نتایج: 91891  

2010
S.-J. Wei X.-L. Zhang J. Shi G. Xiang

Abstract—Synthetic Aperture Radar (SAR) can obtain a twodimensional image of the observed scene. However, the resolution of conventional SAR imaging algorithm based on Matched Filter (MF) theory is limited by the transmitted signal bandwidth and the antenna length. Compressed sensing (CS) is a new approach of sparse signals recovered beyond the Nyquist sampling constraints. In this paper, a hig...

Journal: :Plant physiology 2011
Beibei Jing Shaohua Xu Mo Xu Yan Li Shuxin Li Jinmei Ding Yuelin Zhang

Systemic acquired resistance (SAR) is a defense mechanism induced in the distal parts of plants after primary infection. It confers long-lasting protection against a broad spectrum of microbial pathogens. Lack of high-throughput assays has hampered the forward genetic analysis of SAR. Here, we report the development of an easy and efficient assay for SAR and its application in a forward genetic...

ژورنال: :علوم و فناوری فضایی 0
حمید دهقانی علی ریوندی مجتبی بهزاد فلاح پور کیومرث موسی زاده

سامانه های تصویر برداری راداری sar، مکملی برای سامانه های سنجش از دور الکترواپتیکی هستند و در طی دو دهه اخیر مورد استفاده قرار گرفته اند. پیچیدگی عملکرد در این سامانه ها، به ویژه در مرحله نگاشت، از فضای سیگنال به فضای تصویر، درک نحوه رفتار این سامانه ها را با مشکل مواجه ساخته است. این مسئله توسعه و استفاده از این فناوری را از منظر کاربری و مقابله با آن را از منظر پدافند غیر عامل، به شدت محدود ک...

Journal: :Allergy 2005
G Ciprandi I Cirillo A Vizzaccaro M Tosca G Passalacqua E Pallestrini G W Canonica

BACKGROUND Allergic rhinitis is traditionally subdivided into seasonal (SAR) and perennial (PAR), although the new definitions of persistent and intermittent were recently proposed. We assessed the validity of the traditional classification in a large group of subjects suffering from allergic rhinitis alone. METHODS Young males referred to a Navy Military Hospital for routine fitness visit, a...

2013
Ashish Roy

Synthetic aperture radar (SAR) based on frequency modulated continuous wave (FM-CW) transmission is a viable option for producing high resolution microwave imagery at low heights. In this paper, we show detailed analytical simulation for stripmap mode of FM-CW SAR imaging alongwith SAR images generated from actual airborne FM-CW radar video data collection. Key words—FM-CW, SAR, Range-Doppler, UAV

2000
Bir Bhanu Yingqiang Lin

R ecognition of o cclude d obje cts in synthetic ap erture radar (SAR) images is a signi cant problem for automatic target recognition. In this paper, we present a hidden Markov modeling (HMM) based approach for recognizing objects in synthetic ap ertur eradar (SAR) images. We identify the peculiar char acteristics of SAR sensors and using these characteristics we develop featur ebased multiple...

2008
H. Sun B. Pan Y. Chen J. Li L. Deng

Due to the special imaging model of SAR, its image includes certain special information that unavailable in multispectral image, however, the interpretation of SAR image becomes more difficult than visible image. Therefore, the fusion of SAR image and multispectral image is primarily for the purpose of making better use of SAR image information. For this application, the autoadaptive informatio...

1997
Jakob J. Van Zyl Anhua Chu Scott Hensley Yunling Lou Yunjin Kim Soren N. Madsen

Research on the utility of Synthetic Aperture Radar (SAR) data in many diverse applications has seen great activity in the past decade. In particular, two powerful SAR techniques emerged during this time. Polarimetric SARS were frost demonstrated during the 1980’s and is described by van Zyl et al. [1] and Zebker et al. [2]. Since then polarimetric SAR data have been applied to most disciplines...

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...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید