Geopotential models in the Australian region
Abstract
The ability of three highorder geopotential models (OSU81, GPM2 and OSU86E) to recover the gravity anomaly field (delta g) in the Australian region was tested. The region was divided into 2 x 2 deg blocks, and the mean and rms of the residual gravity (delta g measured  delta g modeled) was found to estimate the fit of the model to the point gravity data. The results showed that OSU81 and GPM2 performed similarly, recovering the delta g with a mean value of less than plus or minus 5 mGal in 63 and 70 percent of the blocks, respectively. However, both these models achieved a fit of worse that was plus or minus 13 mGal in 6 to 7 percent of cases. These were in areas either on or near the coast, or in the Central Australian region, inferring that for a precise geoid slope determination in these regions, a detailed analysis of delta g in region is needed. On the other hand, OSU86E produced a very good result, having a mean fit of less than plus or minus 5 mGal in 80 percent of the blocks, and worse than plus or minus 13 mGal in only 1 percent of cases. The rms values for this model were also improved over the other two models, indicating that for applications requiring highest precision, the preferred model is OSU86E.
 Publication:

Progress in the Determination of the Earth's Gravity Field
 Pub Date:
 June 1989
 Bibcode:
 1989pdeg.rept...23K
 Keywords:

 Australia;
 Calibrating;
 Geoids;
 Geopotential;
 Gravity Anomalies;
 Mathematical Models;
 Ellipses;
 Global Positioning System;
 Goodness Of Fit;
 Matrices (Mathematics);
 Geophysics