<Tr> <Th> Parameter </Th> <Th> Value </Th> </Tr> <Tr> <Td> semi-minor axis </Td> <Td> b = a (1 − f) </Td> </Tr> <Tr> <Td> First eccentricity squared </Td> <Td> e = 1 − b / a = 2f − f </Td> </Tr> <Tr> <Td> Second eccentricity squared </Td> <Td> e ′ = a / b − 1 = f (2 − f) / (1 − f) </Td> </Tr>

The datum on which all latitude is based is the