新的小波滤波算法及其在甚长基线干涉测量中的应用

在甚长基线干涉测量中对航天测控信号进行滤波处理，有利于改善信号质量，提高测量精度。以扩频信号为航天测控宽带信号模型，选择dB1小波进行小波变换滤波。首先提出和推导了小波细节系数极大值传播定理，并给出了相关推论；然后提出了一种基于小波系数重构的小波变换滤波算法，该算法包括四个步骤:最高层小波细节系数处理、其他各层小波系数处理、最高层尺度系数处理和整形输出；最后将该算法应用到甚长基线干涉测量的时延估计中。仿真结果表明了极大值传播定理的正确性以及所提滤波算法对航天测控信号质量改善和时延测量精度提高的有效性。 

A Novel Wavelet Filtering Algorithm and Its application to Very Long

Filter processing is beneficial to improve the quality of received signal and the measuring accuracy of Very Long Baseline Interferometry(VLBI) system. Spread spectrum signal as wideband signal model, dB1 wavelet function is chosen to wavelet transform for filtering. First, propagation rule of detail coefficients’ maximums and some inferences are proposed and deduced. Then, a novel filter algorithm is proposed, which contains four steps: construction of the highest level detail coefficients, construction of the other level detail coefficients, procession of the highest scale coefficients and shaping of filtering output. Finally, the proposed algorithm is applied to delay estimation in VLBI. Simulation results prove the validity of maximum propagation rule and show a quality improvement of TT&C signal as well as a better performance of delay estimation.