摘要
In-field Sound Speed Profile(SSP)measurement is still indispensable for achieving centimeter-level-precision Global Navigation Satellite System(GNSS)-Acoustic(GNSS-A)positioning in current state of the art.However,in-field SSP measurement on the one hand causes a huge cost and on the other hand prevents GNSS-A from global seafloor geodesy especially for real-time applications.We propose an Empirical Sound Speed Profile(ESSP)model with three unknown temperature parameters jointly estimated with the seafloor geodetic station coordinates,which is called the 1st-level optimization.Furthermore,regarding the sound speed variations of ESSP we propose a so-called 2nd-level optimization to achieve the centimeter-level-precision positioning for monitoring the seafloor tectonic movement.Long-term seafloor geodetic data analysis shows that,the proposed two-level optimization approach can achieve almost the same positioning result with that based on the in-field SSP.The influence of substituting the in-field SSP with ESSP on the horizontal coordinates is less than 3 mm,while that on the vertical coordinate is only 2–3 cm in the standard deviation sense.
基金
This study was financially supported by National Natural Science Foundation of China(41931076)
Laoshan Laboratory(LSKJ202205100,LSKJ202205105)
The Special Fund of Chinese Central Government for Basic Scientific Research Operations(AR2115).
