Latitude & Longitude

locate a point on Earth using latitude-longitude coordinates

55 deg 45' N, 37 deg 37' E

find the coordinates of a city

Algiers coordinates

Distances

compute the great-circle distance between points on the globe

23.5S 46.4W to 56.8N 60.6E

compute the distance between cities

San Francisco to Tokyo

compute distances between multiple cities

Buenos Aires to Sao Paulo to La Paz to Panama

compute the distance to the horizon

how far can I see at 30,000 ft

calculate line of sight to the horizon from Mount Everest

compute horizon distance for radio waves

how far can radio waves propagate

calculate radio horizon at 100 m altitude

Bearings

get information about a compass heading

SSW

15 North

Geodetic Data

get information about a geodetic reference ellipsoid

GRS80

compare multiple ellipsoids

Airy 1830, Modified Fischer 1960

get information about a geodetic datum

GDA94

compare multiple geodetic data

NAD27, ITRF00

Geogravity

compute current local gravitational field strength

geogravity

compute gravitational field strength at specified coordinates

geogravity 21.28N 157.60W

Geomagnetism

compute current local geomagnetic field strength

geomagnetism

compute geomagnetic field strength for a given date and location

geomagnetism Oslo on 12 Feb 2007