Tide Height Inversion and Accuracy Analysis Based on GNSS-MR Technology

摘要

The tide height of offshore waters is an indispensable marine geographic information data for marine traffic, offshore environmental management, and marine disaster warning and forecasting. Recently years, with the advantages of low power consumption and low cost, the Global Navigation Satellite System Multipath Reflection (GNSS-MR) technology has become an emerging technical method of tide height measurement. In this article, the observation files of SC02 station in 2018 in Washington state of United States is used to retrieve the distance in vertical direction from antenna phase center to sea surface by using the change of signal-to-noise ratio (SNR) caused by the multipath effect of navigation satellite signal. Afterwards, the elevation based on International Terrestrial Reference Frame (ITRF) is converted to the elevation based on the Mean Lower Low Water (MLLW). And then the tide height of each inversion time relative to MLLW is obtained. Finally, the retrieved tide height is compared and analyzed with the tide height offered by the tide gauge station named FRIDAY HARBOR. The results show that the mean error of the two is about -12 cm, the root mean square error is about 15 cm, and the correlation coefficient is about 0.98. Overall, the retrieved tide height agrees well with the measured tide height. Hence, the tide height retrieved by GNSS-MR technology can make up for the lack of ocean observation data in the coastal waters and plays an important role in marine scientific research.