Approximates this cell union's area in steradians by summing the average
area of each contained cell's average area, using the AverageArea method
from the S2Cell class. This is equivalent to the number of leaves covered,
multiplied by the average area of a leaf. Note that AverageArea does not
take into account distortion of cell, and thus may be off by up to a
factor of up to 1.7.
NOTE: Since this is proportional to LeafCellsCovered(), it is
always better to use that function if all you care about is
the relative average area between objects.
Approximates this cell union's area in steradians by summing the average area of each contained cell's average area, using the AverageArea method from the S2Cell class. This is equivalent to the number of leaves covered, multiplied by the average area of a leaf. Note that AverageArea does not take into account distortion of cell, and thus may be off by up to a factor of up to 1.7.
NOTE: Since this is proportional to LeafCellsCovered(), it is always better to use that function if all you care about is the relative average area between objects.