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The equator is divided into 360 degrees of longitude, so each degree at the equator represents 111,319.5 metres (365,221 ft). As one moves away from the equator towards a pole, however, one degree of longitude is multiplied by the cosine of the latitude, decreasing the distance, approaching zero at the pole.
With this value for R the meridian length of 1 degree of latitude on the sphere is 111.2 km (69.1 statute miles) (60.0 nautical miles). The length of one minute of latitude is 1.853 km (1.151 statute miles) (1.00 nautical miles), while the length of 1 second of latitude is 30.8 m or 101 feet (see nautical mile).
Degrees, minutes and seconds, when used, must each be separated by a pipe ("|"). Map datum must be WGS84 if possible (except for off-Earth bodies). Avoid excessive precision (0.0001° is <11 m, 1″ is <31 m). Maintain consistency of decimal places or minutes/seconds between latitude and longitude. Latitude (N/S) must appear before longitude (E/W).
At an image width of 200 pixels, that is 0.0053 degrees per pixel. At an image width of 1000 pixels, that is 0.0011 degrees per pixel. Latitude: from North to South this map definition covers 1.0136 degrees. At an image height of 200 pixels, that is 0.0051 degrees per pixel. At an image height of 1000 pixels, that is 0.001 degrees per pixel.
Length (m): The length of the equator is close to 40 000 000 m (more precisely 40 075 014.2 m). [23] In fact, the dimensions of our planet were used by the French Academy in the original definition of the metre; [ 24 ] most dining tabletops are about 0.75 metres high; [ 25 ] a very tall human (basketball forward) is about 2 metres tall.
Since one degree is 1 / 360 of a turn, or complete rotation, one arcminute is 1 / 21 600 of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth's circumference is very near 21 600 nmi. A minute of arc is π / 10 800 of a radian.
As one degree is 1 / 360 of a circle, one minute of arc is 1 / 21600 of a circle – such that the polar circumference of the Earth would be exactly 21,600 miles. Gunter used Snellius's circumference to define a nautical mile as 6,080 feet, the length of one minute of arc at 48 degrees latitude.
where φ (°) = φ / 1° is φ expressed in degrees (and similarly for β (°)). On the ellipsoid the exact distance between parallels at φ 1 and φ 2 is m(φ 1) − m(φ 2). For WGS84 an approximate expression for the distance Δm between the two parallels at ±0.5° from the circle at latitude φ is given by