單發多收合成孔徑雷達模擬與實驗

Implementation of SAR Image Processing with SIMO Technique

劉修昀(Hsiu-yun Liu)

指導教授 ： 任玄

國立中央大學/地球科學學院/太空科學研究所/碩士(2014年)

摘要

本論文針對合成孔徑(Synthetic Aperture Radar, SAR)雷達實現單發多收系統進行研究，在方位向(Azimuth)架設多支天線，運用相位中心偏置天線原理(Displaced Phase Centre Antenna, DPCA)配合多通道重構(Multi-channel Reconstruction)的技術對回波訊號做處理，提出在維持方位解析度的情況下，運用單發多收來改善合成孔徑雷達的測繪帶寬度。
藉由實驗驗證基於方位向多天線的合成孔徑雷達(SAR)實現方法。通過在方位向上安置多個相位中心偏置的天線來降低系統對脈衝重複頻率(Pulse Repeat Frequency, PRF)的要求，並模擬在衛載SAR系統中運用單發多收(Single Input Multiple Output, SIMO)技術，探討測繪帶寬度與方位解析度之情況。但由於在實驗中會產生由脈衝重複頻率的變化造成信號非均勻採樣的因素，因此本文採用了多通道重構算法與DPCA技術來恢復均勻採樣信號。
驗證方式以三通道模式SAR系統在暗室(chamber)進行實驗，通過實驗驗證了該算法的有效性，並可以解決因PRF值變化造成的測繪帶寬和方位向解析度之間的矛盾。由模擬和實驗之成像結果，得出能在維持單發單收SAR高方位解析度情況下，擴展測繪帶之寬度，達到高解析度寬測繪帶(High Resolution Wide Swath)的大範圍探測。

關鍵字

合成孔徑雷達 ； 相位中心偏置天線 ； 高解析度寬測繪帶 ； 單發多收技術 ； 多通道重構技術 ； 距離都卜勒成像

並列摘要

In this study, a single-input multi–output (SIMO) scheme is proposed to improve the azimuth resolution of conventional single-input single-output (SISO) Synthetic Aperture Radar (SAR) based on Displaced Phase Centre Antenna (DPCA) technique and Multi-Channel Reconstruction Algorithm (MCRA).
A DPCA SAR scheme can acquire more than one azimuth sampling during one pulse repeated period. Therefore, the required Pulse Repetition Frequency (PRF) can be greatly decreased while enabling a wider imaging swath. A Multi-Channel Reconstruction Algorithm (MCRA) is applied to recover the uniformity of non-uniform sampling signal resulted from the varieties of the PRF. We adopt a three-channel DPCA SAR system for experiments and several simulations are performed to verify the proposed reconstruction algorithm.
The images performance of the proposed method has been compared with conventional SAR. The experimental results show the advances of the SIMO-based SAR with wider swath under the same azimuth resolution.

並列關鍵字

Synthetic Aperture Radar ； DPCA ； HRWS ； SIMO ； MCRA ； RDA

參考文獻

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