Abstract:

The paper presents the results of gross-error detection in the gravimetric data around Bach Long Vi island of Vietnam base on statistical technique of residuals between gravity anomalies computed using seaborne gravimetric data and those gained from the procedure of interpolation by Inverse Distance Weighting (IDW) method from surrounding points (method 1) and those calculated by the use of normalised spherical harmonics coefficients of the Earth Gravitational Model 2008 (EGM2008) (method 2). Both the two methods rely on the results of residual statistics, histogram of the difference and Z statistics of the normal or Gaussian distribution (Z-score). The method 1 resulted in the identification of 48 suspect points and in the second one 27 suspect points have been detected. The criterion to eliminate the observations was based on the recognition of coincident gross-error points by both two methods. By this way, 18 coincident points have been detected, representing 0.064%. This is positive result which shows that gravimetric data around Bach Long Vi island is the high-confident level database