Subresolution scale refers to the fact that models having a horizontal grid interval
of Ax do not properly resolve the behavior of atmospheric features smaller than 4-5Ax, sometimes larger.
For multi- grid to work, several sub-routine must be developed to pass the data from coarse grid to fine grid, from fine grid to coarse grid, and correction of the error at each grid interval
is an important factor for the virtual maps.
Besides exploration is also conducted in the already identified coal blocks through drilling at 800 to 1000 m grid interval
to categorise resources under Indicated Category.
(2) The relative error estimates of the two grid intervals
are not more than [epsilon].
For example the grid intervals
were refined to 5 degree increments except in the polar regions, and as can be seen in the flanking grid scales (-30[degrees] to +30[degrees]) the tick marks were thickened and extended every 5[degrees].
It also depends the data density, their geographical distribution and the grid intervals
. In general, the smoother the gravity anomalies, the more accurate the predicted values.