GPS speed correction method in track inspection based on car-body vibration

A track condition monitoring system with a small general-purpose information terminal that can monitor car-body vibration has been developed. In the track condition monitoring system, the position of the train is identified using GPS speed measured by the information terminal. However, measurement errors come out in the GPS speed due to the multipath effect. To solve this problem, we have examined correction methods to avoid the measurement error. Results showed that the Median filter is effective for the error reduction.