The Great Circle Arc Distance calculator computes the distance between two points on a spherical body along a great circle arc using the Haversine formula based on the latitude and longitude of two points and the mean spherical radius of the sphere.
INSTRUCTIONS: Enter the following:
Great Circle Arc Distance (D): The calculator returns the distance between the two points in kilometers. However, this can be automatically converted to other distance units (e.g. miles or nautical miles) via the pull-down menu.
The Haversine equation is used to determine the distance between two points (x and y) on the Earth based on a mean spherical earth radius. The Haversine - Distance equation is important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. It is a special case of a more general formula in spherical trigonometry, the law of haversines, relating the sides and angles of spherical triangles. The first table of haversines in English was published by James Andrew in 1805. Florian Cajori credits an earlier use by Jose de Mendoza y Ríos in 1801. The term haversine was coined in 1835 by Prof. James Inman.
The haversine formula is:
`D = 2 *sin^-1(sqrt(sin((lat2 - lat1)/2)^2 + sin((lon2 - lon1)/2)^2 * cos(lat1) * cos(lat2))) * r`