Correlator compensation requirements for passive time-delay estimation with moving source or receivers
Correlator compensation requirements for passive time-delay estimation with moving source or receivers
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DOI：
10.1109/tassp.1980.1163391
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发表时间：
1980-04
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影响因子：
--
通讯作者：
W. Adams;J. Kuhn;W. Whyland
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文献类型：
--
作者：
W. Adams;J. Kuhn;W. Whyland
本文分析了声源或接收机运动对互相关器输出的影响，互相关器用于估计基线上的声源时延差。对于窄带和宽带解调器，需要时变相关器的延迟补偿的情况下，二次信号延迟差的变化进行量化。出现的两个有用的概念是1）源信号的三维延迟/延迟速率/延迟加速度平均模糊函数，和2）等效τ域滤波器，其将源自相关函数变换成失配相关器的平均输出。所需的相关器补偿近似为与输入延迟差函数匹配的二次延迟调制。对于窄带信号的3 dB峰值输出损耗，最大允许延迟率失配将在相关积分时间T期间在质心频率f 0处产生158°的相位旋转，而允许的最大延迟-加速度失配将在中心（t = 0）和每个边缘之间的f0处产生156°的二次相位旋转（t = ± T/2）。对于宽带信号，失配容限变得更紧约11%。
An analysis is given of the effects of source or receiver motions on the output of a cross correlator used to estimate the source time-delay difference across a baseline. For both narrow-band and wide-band correlators, the need for time-varying correlator delay compensation is quantified for the case of a quadratic signal delay-difference variation. Two useful concepts which emerge are 1) the three-dimensional delay/delay-rate/delay-acceleration mean ambiguity function of the source signal, and 2) the equivalent τ-domain filter, which transforms the source autocorrelation function into the mean output of the mismatched correlator. The required correlator compensation is approximately a quadratic delay modulation matched to the input delay-difference function. For 3 dB peak output loss with a narrow-band signal, the maximum allowable delay-rate mismatch will produce 158° of phase rotation at the centroid frequency f 0 during the correlation integration time T, while the maximum allowable delay-acceleration mismatch will produce 156° of quadratic phase rotation at f 0 between the center (t = 0) and each edge (t = ± T/2) of the correlator integration window. For broad-band signals, the mismatch tolerances become about 11 percent tighter.