Latitude extends from 0 equator to 90 north and south respectively, with N north latitude and S south latitude. Extending from theprime meridian 0 to the east and west by 180 is longitude, e east longitude and w west longitude.
Basic introduction
What is a warp?
Meridian, also known as meridian, is an auxiliary line assumed by human beings for the convenience of measurement, and is defined as an arc connecting the north and southpoles on the surface of the globe andperpendicular to the latitude. All the great circles on the earth that cross the ground through theplane of the earth’s axis are called “warpcoils”. A semicircle divided by twopoles through a coil is called a “meridian”. Any two meridians are equal in length and intersect at the north and southpoles. Each meridian has its corresponding numerical value, which is called longitude. The meridian indicates the north-south direction. The origin of meridian naming: in the apparent motion trajectory of a celestial body, allpoints on the same meridian appear at the same time as the upper meridian (noon) and the lower meridian (child). When different meridians have differentplaces. It is earlier in the east and later in the west. Important meridians once caused an international dispute, and it was not until 1953 that Greenwich chose two meridians, 20°w and 160°e, as the boundary between the eastern and western hemispheres. The zero meridian on the globe is called theprime meridian or Greenwich mean line. The zero meridian runs straight through the Greenwich Observatory in London. The length of the warpis about 20037km, but the length of each warpis slightly different.
Why is the meridian also called meridian?
The longitude and latitude lines are drawn on globes and maps in order to determine theposition and direction on the earth, but the longitude and latitude lines are not drawn on the ground. However, it is not difficult for you to see the longitude of yourplace: stand a bamboopole on the ground, and when the sun rises at the highest noon, the shadow of the bamboopole is the longitude of yourplace. Because the meridian indicates the north-south direction, it is also called meridian.
Why should the Greenwich Meridian (i.e. theprime meridian) be taken as the 0 meridian?
Theprime meridian, also called zero meridian, is a standard reference meridian established to determine the geographical longitude and coordinate the measurement of time. There is a natural zero latitude-equator on the earth, but there is no natural zero longitude. Therefore, theprime meridian can only be artificially selected from countless meridians. The originalprime meridian was set by various countries to determine theposition.
With the development of navigation, this “fragmented” situation has gradually changed. In 1767, the director of Greenwich Observatory, Maskailin, compiled the British Nautical Astronomical Calendar, which takes the Greenwich Meridian as the zero meridian of the earth and celestial sphere. The book was soon adopted by many navigators after itspublication.
In 1871, the first international geographical society was held in Antwerp, Belgium, and the meeting made a resolution: “Greenwich Meridian should be adopted as the zero meridian in the charts of all countries, and it will be implemented within 15 years”.
The 7th International Geodetic Conference was held in Rome in October, 1883. The conference resolved: “Theprime meridian mustpass through the first-class observatory. Considering the fact that 90% of seafarers engaged in overseas trade have calculated theposition (longitude) of ships based on the Greenwich meridian, governments should adopt the Greenwich meridian as theprime meridian”. On the issue of time, the meeting held that it will bring great convenience when a unified world should be adopted in international exchanges.
On October 1st, 1881, the International Meridian Conference was held in Washington, USA. At last, the conferencepassed seven resolutions, among which:
Resolution 2: Governments attending the conference should adopt the Ziniu linepassing through the meridian center of Greenwich Observatory as theprime meridian.
Resolution 4: When universal time is advocated, local time or standard time can also be used if necessary.
Resolution 5: World Day starts at 0: 00 on theprime meridian, and Civil Day also starts at 0: 00 at midnight.
At thispoint, theprime meridian and universal time were finally established and recognized by most countries
Theparallel is also called “latitude circle”.
a circleperpendicular to the earth’s axis and circling the earth. The equator is the largest latitude circle.
corresponds to the meridian.
The center of the coil is located on the earth axis; The latitude indicates the east-west direction; The latitude line on the earth isperpendicular to the longitude line; Equatorial latitude circle is the longest. Latitude circle, the twopoles, shrinks to a little. The length of weft is different, each weft is a circle, and the weft is divided into south latitude and north latitude.
The longitude and latitude on the globe are imaginary arcs, and there are countless longitude and latitude. In order to distinguish each longitude and latitude,people mark them with degrees.
On the north and south sides of the equator, many circlesparallel to the equator are drawn, that is, “weft circles”; The line segments that make upthese circles are calledparallels.
From the northpole to the southpole, many large circlesperpendicular to the equator of the earth in the north-south direction can be drawn, which are called “meridional circles”; The line segments that make upthese circles are called warps
The wefts extend from east to west andpoint to east. ~ ~ ~
Longitude (λ)
The longitude line isprojected as a curved and vertical line on the map, but it is actually half of the great circle.
Latitude (φ)
Latitude lines appear to be horizontalparallel lines on the map, but they are actually circles with different radii. Allpositions with the same specific latitude are on the same latitude.
The latitude of the equator is 0, which divides theplanet into the southern hemisphere and the northern hemisphere.
Those arcs drawn directly on the globe
