Abstract:

The target of this paper is transformation of the gravity observations between the tide systems. In this paper the mean-tide, zero-tide, nontidal systems and the effect of tide on gravity observations were reseached. Then, the formulas for transformation of the gravity observations between the tide systems were searched and applied. The gravity contributions of the tide were computed for the points distributed along the Vietnam territory. The experimental results have show that the effect of the tide on gravity are remarkable; They depend on latitude of the observation points; In the diffirent tide systems the gravity contribution of the tide are diffirence. For Vietnamese territory, the corrections for transformation from the mean tide system to the zero tide system varies from 0.0141 mGal to 0.0286 mGal, from the mean tide system to the nontidal system varies from 0.0164 mGal to 0,0332 mGal, from the zero tide system to nontidal system varies from 0.0023 mGal to 0.0046 mGal. So, after solving the geodesy problems, the gravity observations need to be transfered to the united tide system.