新穎的混合式角反射器法於全極化合成孔徑雷達校正

Improvement of Hybrid Polarimetric Calibration Technique for SAR Using Corner Reflectors

陳憲偉(Shian-wei Chen)

指導教授 ： 任玄

國立中央大學/太空及遙測研究中心/遙測科技碩士學位學程/碩士(2014年)

摘要

全極化合成孔徑雷達系統已經被廣泛的運用在地表分類、物理參數反演上，特別是在比較兩幅影像時、或者是比較影像與理論時，極化校正非常重要。
然而，在應用全偏極雷達資料時，有別於傳統單偏極雷達只需進行輻射校正即可獲得目標物的散射特性，全偏極資料更在乎的是相位的相對關係，因此全偏極合成孔徑雷達還需進行校正各個極化之間相對的相位、振幅不平衡、串擾，才能讓資料更廣泛的被應用。
本文中對極化校正提出一個更精緻的模型，以及更精準的解出模型中的未知數，並利用此校正矩陣進行全極化雷達系統的校正。本文利用三角反射器、兩面角反射器、旋轉22.5度和45度的兩面角反射器進行實驗室陸基全極化雷達的校正與Pi-SAR系統的校正，經由此校正方法，能使振幅誤差可降至0.5dB，相位誤差可降至5度。

關鍵字

雷達 ； 全極化 ； 全極化校正

並列摘要

Fully polarimetric synthetic aperture radar (SAR) has wide applications for terrain classification, land-use and physical parameters retrieval, etc. Calibration of quad-polarized SAR data is essential for understanding actual polarimetric signatures, especially comparing data between scenes, or comparing observation with theory.
The proposed calibration method relies only on the characteristics of the calibration targets and requires no assumptions regarding scene statistics and radar characteristics. It allows the correction of polarimetric distortions of the radar system using only three different kinds of the following calibration corner reflectors: trihedral, dihedral, 22.5degree and 45 degree rotated dihedral. Validation of the proposed method is made by using chamber measurements and airborne L-band Pi-SAR data. The experimental results show that the amplitude error can be reduced to as small as 0.5dB, while the phase error is less than 5 degrees.

並列關鍵字

radar ； polarimetric ； polarimetric calibration

參考文獻

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