High Accuracy GPS Deformation Monitoring via Errors Cancelling by ANC and Wavelet Analysis

The Global Positioning System (GPS) has been used in the health monitoring of large structures in recent years since it is weather independent, capable of autonomous operation, and does not require a line-of-sight between target points. But it is well known that there are various kinds of error sources impacting on high precision GPS positioning. In order to derive a relatively noise-free time series from the GPS results, an integrated method based on Adaptive Noise Cancelling (ANC) principles and wavelet de-noise method is presented. To verify the effectiveness of the method, an experiment is carried out, the data analysis results indicate that the adaptive noise canceller is a powerful signal decomposer, which can significantly mitigate multipath effects since multipath tends to exhibit the same pattern between consecutive days; wavelet filter is a suitable tool to separate random noise that cannot be filtered by adaptive noise cancellation method form signal. This kind of combination is superior to single filtering method.