Cell area is the one metric the three grids share, and cellArea answers it in square metres for each of them. The length of a directed edge and the great-circle distance between two temporal points are stated in the H3-specific section.
Return the area of a cell, and the temporal area of each cell in a trajectory
cellArea(cell) → float8 cellArea(tcell) → tfloat
A cell area shrinks toward the poles on the QUADBIN grid, as Web-Mercator squares cover progressively less ground at higher latitudes. An H3 or an S2 cell is defined on the sphere, so its area varies only with resolution and with the cell's position in the base solid.
The unit is the square metre for every grid, so cellArea answers the same quantity whichever grid holds the cell.
SELECT cellArea(th3index '871fa44a8ffffff@2001-01-01'); -- 4441914.270110932@2001-01-01 SELECT cellArea(tquadbin '48a6227affffffff@2001-01-01'); -- 609209287.1146417@2001-01-01 SELECT cellArea(ts2cell '47c3c@2001-01-01'); -- 4145164039.0857196@2001-01-01