Feature Extraction of Structure Natural Vibration and Multipath Separation Based on Wavelet Packet Decomposition

Multipath is the dominant error source in the structural vibration monitoring using GPS. In order to obtain the characteristics of structure natural vibration accurately, both the frequency characteristics of the multipath and the structural vibration are analyzed, then wavelet packet decomposition is employed to extract specifical components in different scales and spectral analysis is adopted for frequency characteristic analysis. Experimental results show that the wavelet packet can be used to separate multipah error and extract the vibration feature effectively. In addition, the actual vibration frequency obtained using GPS conforms its theoretical value and it has high stability.