Frequency-swept interferometry(FSI) is a well-known ranging technique, but it suffers from three problems, namely, the Doppler effect, the frequency-sweep nonlinearity, as well as the slow frequency-sweep rate. The fi...Frequency-swept interferometry(FSI) is a well-known ranging technique, but it suffers from three problems, namely, the Doppler effect, the frequency-sweep nonlinearity, as well as the slow frequency-sweep rate. The first two problems hinder the measurement accuracy, while the third problem limits the measurement rate. In this paper, we present a dynamic FSI(DFSI) that solves these three fundamental problems simultaneously. The DFSI consists of two auxiliary interferometers(AU1 and AU2) and two measurement interferometers(FSI and frequency-fixed interferometry(FFI)). We use FSI to obtain the Doppler and nonlinearity affected ranging signal, AU1 to monitor the frequency-tuning nonlinearity in the frequency-swept laser(FSL), and FFI and AU2 to constitute a laser vibrometer for monitoring the target motion-induced Doppler effect. Then, a novel signal fusion processing technique is applied to reconstruct the real dynamic distance from the above-measured signals. The dynamic ranging error caused by the Doppler effect and frequency-sweep nonlinearity in FSI can be eliminated and the dynamic distance at each sampling point can be obtained. The validity of this method is demonstrated by numerical experiments.展开更多
基金supported by the Sustainably Supported Foundation of SASTIND (No.HTKJ2021KL504008)the National Natural Science Foundation of China (No.51805054)+1 种基金the China Postdoctoral Science Foundation (No.2018M643405)the Technology Innovation Platform Project of Aero Engine Corporation of China (No.SHYS-GXDPL-18)。
文摘Frequency-swept interferometry(FSI) is a well-known ranging technique, but it suffers from three problems, namely, the Doppler effect, the frequency-sweep nonlinearity, as well as the slow frequency-sweep rate. The first two problems hinder the measurement accuracy, while the third problem limits the measurement rate. In this paper, we present a dynamic FSI(DFSI) that solves these three fundamental problems simultaneously. The DFSI consists of two auxiliary interferometers(AU1 and AU2) and two measurement interferometers(FSI and frequency-fixed interferometry(FFI)). We use FSI to obtain the Doppler and nonlinearity affected ranging signal, AU1 to monitor the frequency-tuning nonlinearity in the frequency-swept laser(FSL), and FFI and AU2 to constitute a laser vibrometer for monitoring the target motion-induced Doppler effect. Then, a novel signal fusion processing technique is applied to reconstruct the real dynamic distance from the above-measured signals. The dynamic ranging error caused by the Doppler effect and frequency-sweep nonlinearity in FSI can be eliminated and the dynamic distance at each sampling point can be obtained. The validity of this method is demonstrated by numerical experiments.
