WIDE-FIELD WIDE-BAND INTERFEROMETRIC IMAGING: THE WB A-PROJECTION AND HYBRID ALGORITHMS
WIDE-FIELD WIDE-BAND INTERFEROMETRIC IMAGING: THE WB A-PROJECTION AND HYBRID ALGORITHMS
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宽视场宽带干涉成像：WB A 投影和混合算法
DOI：
10.1088/0004-637x/770/2/91
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
K. Golap
中科院分区：
文献类型：
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作者：
S. Bhatnagar;U. Rau;K. Golap
天线主波束 (PB) 方向图随时间、频率和极化的变化形成了大多数射频频段的主要方向相关效应之一。这些增益也可能因天线而异。较早发布的 A 投影算法考虑了窄带天线 PB 在全极化下的影响。在本文中，我们提出了宽带 A 投影算法（WB A 投影），将宽带宽的影响纳入 A 项本身，并表明所得算法同时校正了 PB 的时间、频率和偏振相关性。我们讨论了 WB A 投影和多项多频合成 (MT-MFS) 算法的结合，用于同时绘制宽视场的天空亮度分布和光谱指数分布。我们还讨论了窄带 A 投影算法在混合成像方案中的使用，该算法解释了图像域中 PB 的频率依赖性。
Variations of the antenna primary beam (PB) pattern as a function of time, frequency, and polarization form one of the dominant direction-dependent effects at most radio frequency bands. These gains may also vary from antenna to antenna. The A-Projection algorithm, published earlier, accounts for the effects of the narrow-band antenna PB in full polarization. In this paper, we present the wide-band A-Projection algorithm (WB A-Projection) to include the effects of wide bandwidth in the A-term itself and show that the resulting algorithm simultaneously corrects for the time, frequency, and polarization dependence of the PB. We discuss the combination of the WB A-Projection and the multi-term multi-frequency synthesis (MT-MFS) algorithm for simultaneous mapping of the sky brightness distribution and the spectral index distribution across a wide field of view. We also discuss the use of the narrow-band A-Projection algorithm in hybrid imaging schemes that account for the frequency dependence of the PB in the image domain.