An Evaluation of Methods for Marine Gravity Anomaly Deriving from Satellite Altimetry A Case Study over the Oman Sea

Modeling of gravity field has many application in geosciences such as geodesy، geophysics، and oceanography and tectonic. Marine Gravity observations due to factor such as oscillation and accelerations of ship، also mechanical errors that are greater in water have low precision. Satellite altimetry provide detailed information about geoid changes and its slope changes over the oceans. in geodesy we can convert geoid and its slope (deflection of vertical component)، to gravity anomaly using spectral analysis methods. There are two integral equation to estimate gravity anomaly from geoid and deflection of vertical، stokes integral and vening meinesz integral. In this paper method of marine gravity anomaly deriving from satellite altimetry are introduced and then using satellite altimetry data estimate marine gravity anomaly over Oman Sea that is a Deep region. Then for control precision of methods، use marine gravity anomaly points that have corrected and collected by national geophysical data center (NGDC). our result show that in gravity anomaly estimation from satellite altimetry using Deflections of vertical as observation and spectral kind of vening meinesz integral as method have a RMS of 4. 2 mgal in comparison with shipborne data، while the using geoid as observation and spectral kind of stokes integral as method، have 4. 38 mgal in comparison with shipborne data. This indicate spectral kind of vening meinesz integral have advantage in comparison with spectral kind of stokes integral.