合成口徑雷達資料之輻射校正

Abstract

在現今的遙測界□使用合成口徑雷達所獲取的影像來作遙測的應用已經是 非常熱門的事了。合成口徑雷達不但能在不受天候的影響下近乎即時的獲 取地面影像，還能從影像中獲得出目標物的背向反射係數，使遙測的應用 得以定性與定量。這就是為什麼需要輻射校正工作-以確保所有的資料即 使在不同的系統或不同的時間下所獲取的，皆能處於一個相同的輻射基礎 上。在本文中，將對中央大學遙測中心的衛星雷達影像分別做三種輻射校 正，天線增益、距離擴散、入射角影響，並探討三種校正項會對影像產生 多大的修正量。最後對影像求取遙測中心的校正常數以利使用者得到目標 物的背向反射係數。 It is very common to use the images acquired by from Synthetic Aperture Radar (SAR) for the application in remote sensing . SAR system not only generates near real-time image data under all weathers, but also extracts the backscatter coefficient of the targets, which expands the applications of remote sensing. The radiometric calibration based on the same reference frame is required to ensure that all data can be used effectively even generated from different systems or on different time. In this thesis, three calibration terms, including rang spreading、 antenna pattern and incidence angle , are applied to the image data supplied by Center for Space and Remote Sensing Research of National Central University. And we also verify the steps of calculating the calibration constant-K.