Applying Time-Frequency Distribution Function to DOA of Mobile Active Sensor

時頻分佈函數於移動式主動感測器方位估測之應用

張順雄(Shun-Hsyung Chang) ； 劉俊成(Jun-Cheng Liu) ； 邱志偉(Chih-Wei Chiu)

《Journal of Marine Science and Technology》 9卷2期 (2001/12) Pp. 161-166

https://doi.org/10.6119/JMST.200112_9(2).0012

摘要

由於時頻估測被廣泛應用在雷達、聲納與地震學等領域，因此增加時頻估測的精確度一直是科學家們追求的目標。現行的高解析度時頻估測方式大多是採用時頻分佈信號。本論文結合多孔徑雷達信號與陣列信號處理方式，並利用時頻分佈函數進行主動偵測器物體的方位估測。由主動偵測器偵測目標物的回應訊號與分析時間與相位延遲所造成在訊號頻率上的非穩態變化，可以解析出頻率變化的物理特徵值及找出目標物與參考座標的對應角度與位置，其可以實際運用在飛行物與車輛的方位估測。藉由這種方式可以避免繁雜的多維度傅立葉投射計算、特徵化程序與頻譜掃描，並可以有效的減少所需要的動態感測元件。但是並非所有的時頻分佈函數都適合用於多目標物偵測，因為其會造成高交關項並容易受雜訊影響。因此本論文提出一種新的時頻分佈函數MACK（Modified Adaptive Cone Kernel）。MACK可以有效的消除交關項，且具有良好的時頻分析能力。模擬結果顯示MACK，函數在飛行導航與船隻定位的應用上是相當有用與可靠的。

關鍵字

方位估測 ； 時頻分佈函數 ； 修正型可適性錐 ； 形核心函數

並列摘要

Increasing the accuracy of time-frequency detection in engineering is always the goal that scientists are striving to achieve, because it is widely applied in the fields of Radar, Sonar, the exploration of earthquake epicenter etc. The current high-resolution time-frequency methods are mostly based on the structure of time-frequency distribution function of Cohen Family. Time frequency distribution function can trace the instantaneous frequency of nonstationary signal. This paper combines the process principle of multi-aperture Radar and Array signal and applies time-frequency distribution function in DOA of active sensor devices. By decoding of physical characteristics from the changes of frequency, which can be done by using the active devices to detect the response signal of the target and the analyzing the nonstationary changes of frequency caused by the delays of time and phase, the related positions and contained angle of target and reference can be found and practically applied to the target DOA of aircraft and vehicle engineering. By doing that, the troublesome multi-dimensions Fourier projection calculations, eigen factoring and Spectrum scan can be avoided and reduces the huge amount of active dynamic sensor devices required for vehicles, but not all of the distribution functions can be used to analyze the multi-objects. For example, Wigner distribution function is one of the case, because contains the high cross-terms and is easily to be interfered by noise. In this paper, the application of a new time-frequency distribution function MACK (Modified Adaptive Cone Kernel) is proposed. The application general form is derived and proved, also the signals of time-varying spectrum are decoded. MACK can eliminate all of the cross-terms and the time-frequency analysis ability is high and uniform. The simulation results showed that the MACK function is very realistic and useful on aircraft navigation and vessel location.

並列關鍵字

direction of arrival ； time-frequency distribution function ； modified adaptive cone kernel