因為合成孔徑雷達是主動式的微波感測器，在地球資源探勘、全球災害防制、環境變遷偵測等方面的應用上，具有較不被天候影響的特性，所以合成孔徑雷達在一些立即性的觀測上佔有重要的地位。然而傳統的合成孔徑雷達系統是以發射線性調頻脈衝波實現，此類的系統設計必須使用一組大功率輸出模組製造脈衝波，將不利於輕型載具攜帶。線性調頻連續波式合成孔徑雷達，可用較為輕巧的架構，低廉的成本來實現高品質的合成孔徑雷達影像。 本篇論文將依序探討合成孔徑雷達的運作原理，將傳統的脈衝式雷達系統去除脈衝波成分，以線性調頻連續波的方式發射訊號，進而推導出新式雷達架構的合成孔徑成像演算法，為了驗證出這一連串的推論，我們使用儀表系統結合微波電路和電腦設計出一個線性調頻連續波式的雷達系統，也完成了測試。在測試中將以訊號產生器產生線性調頻源經由外部的微波電路發射，接著將接收訊號做解調處理，再用筆記型電腦連結頻譜分析儀擷取紀錄回波基頻信號，將這樣的一組資料代入我們的合成孔徑演算中合成出影像。最後我們將對測試場地做地物調查，用以驗證影像上的正確性。Synthetic aperture radars (SAR) is an active microwave sensor widely used in earth resources exploration, global hazards detection, environmental change detection and other applications due to its all weather operation capability. Linear frequency modulated pulses are used as transmitted signal by conventional SAR. However, the pulse SAR systems are not suitable to be carried by light platforms, because they must use big power generator to produce necessary high power pulses. Linear frequency modulated continuous wave (LFM-CW), on the other hand, is able to achieve high performance with smaller structures and lower cost. This thesis focuses on the design and test of a LFM-CW SAR, followed by de-signing a novel image focusing algorithm for it. In order to verify the system archi-tecture, well-controlled instruments, RF circuits and computer are utilized throughout the design and construction of the system. In the test, a signal generator is used to generate chirp source fed to the RF circuit including antenna for transmitting. The re-ceived signal is then demodulated to baseband and stored for further SAR processing. The analysis of the image quality is performed through a series of field tests. It is demonstrated that the system is able to achieve the required specifications.
