Study On High-rate Epoch By Epoch GPS Positioning And Its Application In Bridge Of Vibration Monitoring

The purpose of this subject is to study the application of high-rate GPS data in monitoring of bridge vibration. Firstly, we elaborated the processing method of high-rate GPS single epoch positioning data and analyzed its positioning accuracy through a large number of this date. In order to improve the location accuracy, we also did intensive study on how to improve the accuracy of dynamic calculation of troposphere delay. At last, we use a 10-Hz GPS receiver as a 0.1s displacement meter to study the characteristics of bridge vertical vibration. By using track-the double difference positioning module in GAMIT/GLOBK10.4, we have studied the theory of single epoch data processing and have carefully read the detailed description of track and then high-rate GPS measured data was calculated with the help of this module.We have analyzed the influence of different ephemeris products on 1-Hz GPS single epoch positioning accuracy. Because of the update cycle and different precision of the ephemeris product, different ephemeris for GPS single epoch positioning results are quite different. By analyzing the result of different length of the baseline by adding different ephemeris products, we have evaluate the effects of different ephemeris products and different baseline length on the GPS single epoch positioning accuracy with the help of the root mean square error.We have studied the calculation method of dynamic troposphere delay. We find that the dynamic troposphere delay calculation method is not perfect by the comparison of dynamic and static. Put the static troposphere delay as the standard value, we have got the corresponding correction of the dynamic method for each station. By the comparison of dynamic method which added the correction to static, we have found the difference between the two have decreased from centimeter level to the millimeter, which verified the validity of the correction.By using high-rate GPS receiver, we have got 10-Hz bridge vibration data and with the help of track measured data are calculated and we have got the 3D dynamic information of bridge monitoring points. We use wavelet analysis method to remove the trend and extracting the main vibration information and we got the main vibration information whose cycle is 100 seconds.