Latitude and longitude are the combination of longitude and latitude, forming a coordinate system, which is called geographical coordinate system. It uses the spherical surface of three-dimensional space to define the space on the earth, and can mark the spherical coordinate system anywhere on the earth.
Meridian, also known as meridian, is an auxiliary line assumed by human beings for the convenience of measurement, and is defined as a semi-circular arc on the great circle connecting the north and south poles on the earth's surface. Any two meridians are equal in length and intersect at the North Pole and the South Pole. Each meridian has its corresponding numerical value, which is called longitude. The meridian represents the north-south direction.
Extended data:
Calculation method of latitude and longitude:
1, two days first.
For example, in a certain place in China, the shortest time of the polar shadow at noon is 13: 20, and the ratio of the extreme length to the shadow length is 1, so we can know that the place is 45 north latitude (tgα =1) and east longitude 100( 1 hour from/kloc).
2. The longitude calculation algorithm from two days to one day is that the constant latitude is α+23.5 in the winter solstice and α-23.5 in the summer solstice in the northern hemisphere, which can be added or subtracted on any day.
3. Correction algorithm: that is, the difference between two minutes or two days to the sun multiplied by 94/365. For example, the vernal equinox on February 20, 200317, 2065438+March 22 is 33 days, that is, the direct point of the sun is in the south latitude.
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