The Hurricane Imaging Radiometer, HIRAD, is a microwave remote sensor for improved airborne surveillance of ocean surface winds and rain in hurricanes. HIRAD uses a 1-D synthetic aperture thinned array to image the ocean at four frequencies between 4 - 7 GHz. This paper presents a brief description of the HIRAD array antenna and an analysis of some of the methods used in computing reconstructed brightness temperature, Tb, images. Various aperture taper functions for shaping the synthesized array patterns are discussed along with their application to several representative Tb profiles from simulations of cross-track scans in Hurricane Frances. Requirements in matrix conditioning to improve the image reconstruction process will also be discussed. Results will demonstrate the importance of these two image reconstruction considerations to the image smoothing and spatial resolution trade-off and to the Gibbs phenomenon ringing artifacts from the Fourier inversion process.
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机译:飓风成像辐射计Hirad是一种微波遥控传感器,可改善海洋表面风和飓风中的雨水的空气载体监控。 Hirad使用1-D合成孔径稀释阵列,在4 - 7 GHz之间的四个频率下映像海洋。本文介绍了HiRAD阵列天线的简要说明,以及用于计算重建亮度温度的一些方法,T B IM>,图像。讨论了用于整形合成阵列模式的各种孔径锥形功能以及其应用于几个代表性T B INF>曲线,从飓风弗朗西斯的跨轨扫描的模拟。还将讨论矩阵调理的要求,以改善图像重建过程。结果将展示这两个图像重建考虑对图像平滑和空间分辨率的重要性以及从傅里叶反转过程中振荡伪影的图像平滑和空间分辨率。
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