【摘要】 为了提高捷联寻北仪在动态干扰下的精度,采用小波去噪法对寻北仪的原始输出信号进行处理.通过对多尺度下信号的小波变换系数及模极大值的跟踪,发现有用信号为平稳信号,而干扰信号的模极大值并不都随尺度的增加而减少,因此提出模极大值与软阈值相结合的方法.对随尺度增大的模极大值用其左右相邻几个非模极大值平均值替代,滤去李氏指数大于0的干扰信号;对李氏指数小于0的噪声采用软阈值法去噪.该方法可使寻北精度达到1mrad.更多还原

【Abstract】 To improve the accuracy of a strapdown north finder used under dynamic conditions of disturbances, a new wavelet denoising method is introduced to process the original output of the north finder. From wavelet transform modulus across scales, it is seen that useful signal is stable and some maximum modules does not decrease in larger scales. So maximum modules and soft-thresholding are proposed.Some maximum modules whose values grow larger with increase in their scales are substituted by mean value of non-maximum modules adjacent to them. Thus disturbances whose Lipschitz exponent is larger than zero are filtered. Soft-thresholding is used to filter the noise whose Lipschitz exponent is smaller than zero. The method can improve the accuracy of strapdown finder to 1 mrad.更多还原