However, he did not explain how to calculate the great-circle distance.
Thus the problem of finding the great-circle distance between points A and B is reduced to finding the central angle, 0, of the sector in Figure 7.
Make sure that they measure the angle in radians and multiply it by the radius of the Earth to get the great-circle distance.
A closed-form formula for the great-circle distance
On the earth's surface, the spatial distance, or geo-distance, can be defined as the sphere distance with shortest path, which is the curve of great-circle distance (Wikipedia, 2009a).
This requires the calculation of the distance from a given point to the line, the arc line on the surface of the earth, defined by the two locations based on the great-circle distance.
There are a number of sphere formulae, such as great-circle distance equation, that can be used.
Genetic distance is not associated with the great-circle distance between islands (r = 0.
The relative importance of sea barriers to population subdivision compared with land separation is further emphasized by the lack of an association between genetic distance and great-circle distance, because the latter measure is dominated by overland distance.
The contemporary minimum sea-crossing distance between islands accounts for 67% of the variance of genetic distance, whereas the great-circle distance between islands does not account for any significant part of the variance of genetic distance (a result also observed in the Philippine C.
The great-circle distances between all pairs of island populations of C.