Research Of Marine Gravity Anomalies Inversion Based On Multi-satellite Altimeter Data

Gravity anomalies reflect uneven distribution of the Earth's internal mass and play a great significance role in geophysics.Marine gravity anomalies reflect the internal structure of the ocean and related to the topography of the marine floor and geoid,widely used in the construction of geoids,marine dynamic environment research,and offshore oil and gas exploration.The traditional measurement methods can not cover the entire marine.Multisatellite altimeter data provides large-scale,high-precision observation data that can invert high-precision,high-resolution marine gravity anomalies.This paper combines new altimeter data Jason-2/GM,Jason-3,Sentinel-3A and other satellite altimeter data to invert the Chinese sea and its vicinity(0°~45°N,80°~160°S)1?×1? marine gravity anomaly based on the remove-restore method and the inverse Vening-Meinesz formula,and comparing results with the EGM2008 gravity field model,shipborne data and Sanwell V25.1 model.The main results as follows:(1)Data editting,collinear processing,and crossover adjustment were performed on multisatellite altimeter data.After processing,the difference of the self-crossover was decreased by a maximum of 12.5 cm,the minimum was increased by 6.1 cm,and the data accuracy was greatly improved.(2)Systematic evaluation of the new altimeter satellite Jason-3 and Sentinel-3A.The results show that the Jason-3 altimeter and radiometer instruments have stable performance and good data availability.The RMS of self-crossover difference is 4.98 cm,and the precision is high.The deviation is 2.93 cm with Jason-2;Sentinel-3A system Stability,good data availability,and the RMS of self-crossover difference is 5.02 cm,accuracy reached expectations.Jason-3 and Sentinel-3A data can be used for high-precision inversion of marine gravity anomalies.(3)Analyzing the influence of the accuracy of altimetry data on the inversion of marine gravity anomalies.Experiments show that the effective combination of altimetry data will improve the accuracy of inversion;when the data has met the requirements of inversion resolution,the addition of low-precision altimetry data will reduce the inversion accuracy.(4)The Multi-satellite altimeter data was used to invert the 1?×1? marine gravity anomalies in the Chinese sea and its vicinity areas.The accuracy is 3.87 mGal compared with the shipborne data in open sea area,which is higher than that of the EGM2008 gravity field model,same accuracy as Sandwell V25.1.