都卜勒UAV尋波平台開發設計

Abstract

中文摘要 針對 GPS 失效、高遮罩或強電磁干擾之極端環境，本研究開發一套「基於都卜勒效應之非合作式尋波定位系統」。該系統整合精密旋轉掃描機構與軟體定義無線電（SDR）接收架構，透過設計具備水平 360 度與俯仰 90 度掃描能力之平臺，並選用高轉速、高負載步進馬達 TK296D-04A，確保在 2.4 GHz 頻段下捕捉訊號之穩定性。技術核心在於利用無人機相對運動產生之都卜勒頻移，結合 SNR、RSSI 與頻譜距離因數（SDF）等多重物理層特徵指標，提升目標與背景雜訊之可分離性。 在演算法層面，本研究導入遞迴最小平方法（RLS）與最小二乘法，針對旋轉過程中產生的頻移曲線進行動態擬合，有效抑制多徑效應與瞬時雜訊干擾。實驗流程採先水平後垂直之二階段掃描，精準推算出無人機之水平方位角與俯仰角。結果顯示，本系統在發射功率未知且不依賴 GPS 數據的條件下，仍能維持高度的重現性與即時三維定位精度，為反制無人機、災後搜救及高遮罩環境監測提供一套低成本、高機動性且具備實用價值之尋波解決方案。 Abstract To address the challenge of GPS-deprived, high-shielding, or intense electromagnetic interference environments, this research develops a "Non-Cooperative Signal Source Localization System based on the Doppler Effect." The system integrates a precision rotary scanning mechanism with a Software Defined Radio (SDR) receiving architecture. By designing a platform with $360∘horizontal and 90∘pitch scanning capabilities—powered by the high-speed, high-torque TK296D-04A stepper motor—stable signal capture at the 2.4 GHz band is ensured. The technical core lies in utilizing the Doppler frequency shift generated by the relative motion of the UAV, combined with multiple physical layer feature indicators such as SNR, RSSI, and the Spectral Distance Factor (SDF) to enhance the separability of the target signal from background noise. At the algorithmic level, this study implements Recursive Least Squares (RLS) filtering and Least Squares estimation to dynamically fit the frequency shift curves generated during rotation, effectively suppressing multipath effects and instantaneous noise interference. The experimental procedure follows a two-stage scanning process—horizontal followed by vertical—to accurately calculate the UAV's azimuth and elevation angles. Results demonstrate that the system maintains high reproducibility and real-time 3D positioning accuracy, even when the transmission power is unknown and GPS data is unavailable. This provides a low-cost, high-mobility, and practical wave-finding solution for anti-UAV systems, post-disaster search and rescue, and environmental monitoring in highly shielded areas.