Partitioning method of equal-area global discrete grids based on warp and weft

A technology of longitude and latitude and equal area, which is applied in the field of global discrete grid subdivision, can solve the problems of grid non-uniformity, inconsistency, and short distance between grid points, and achieve uniform point distribution, convenient statistical calculation, grid net tightening effect

Active Publication Date: 2013-02-20
NORTH CHINA UNIV OF WATER RESOURCES & ELECTRIC POWER
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  • Abstract
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Problems solved by technology

At this time, if the data of the spherical or ellipsoid is converted to the plane for processing in the way of map projection, a series of problems will appear: there will be obvious deviations in the calculation of quantities such as length and area, and there will be Problems such as data overlap, fragmentation, and inconsistency in spatial relationships make it impossible to achieve seamless linking of spatial data around the world, and its validity and accuracy have been questioned
There are obvious deficiencies in the global discrete grid with equal intervals of longitude and latitude: with the increase of latitude, the change of the area and shape of the grid becomes larger and larger, and the distance between grid points becomes shorter and shorter, resulting in a large The data redundancy

Method used

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  • Partitioning method of equal-area global discrete grids based on warp and weft
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  • Partitioning method of equal-area global discrete grids based on warp and weft

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Embodiment 1

[0050] Embodiment one: see image 3 , Figure 4 , the present invention is based on the equal-area global discrete grid subdivision method of longitude and latitude lines, and adopts the hierarchical subdivision principle to carry out discrete grid subdivision on the spherical surface, including:

[0051] 1) Taking the octahedron inscribed in the sphere as the basis for global discrete grid subdivision, the initial subdivision of the sphere is carried out: first, the six vertices of the octahedron inscribed in the sphere are respectively connected to the two poles of the sphere, the equator and the main meridian, 90 The intersections of the ° meridian, the 180° meridian and the 270° meridian coincide;

[0052] Then, do the spherical center projection of the regular octahedron on the spherical surface to obtain 8 spherical triangles R 1 , R 2 ,...,R 8 , to complete the initial division of the sphere, such as image 3 shown.

[0053] 2) The first layer of subdivision: for ...

Embodiment 2

[0056] Embodiment two: see Figure 3 ~ Figure 6 , this embodiment is based on the equal-area global discrete grid subdivision method of longitude and latitude lines, and the following method is used to determine the longitude and latitude lines of each level of grid subdivision, including two cases, the first is the spherical triangular grid subdivision of longitude and latitude lines Determination, the second is the determination of the longitude and latitude of the spherical trapezoidal grid division;

[0057] (1) The method of determining the longitude and latitude of the spherical triangular grid is as follows:

[0058] like Figure 5 As shown, the longitude λ is used respectively 1 , meridian λ 2 and weft represent the 3 sides of a spherical triangle, with parallels and weft Indicates the dividing latitude line, and the longitude line λ 3 Indicates the subdivision meridian, then the meridian λ 3 The longitude of is the mean value of the longitudes of the two lo...

Embodiment 3

[0066] Embodiment three: see Figure 3 ~ Figure 6 , this embodiment is based on the equal-area global discrete grid subdivision method of longitude and latitude lines, and the calculation steps of the latitude and longitude coordinates of subdivided grid nodes are as follows:

[0067] The radius of the earth is about R=6378137.000m, then the surface area of ​​the earth is:

[0068] S=4πR 2

[0069] =4×3.1415926×(6378137.000×6378137.000)

[0070] =511207884675544.00m 2

[0071] After the initial subdivision, 8 identical spherical triangles are obtained, and each spherical triangle is divided into 4 equal areas, then the number of units obtained after subdividing each layer of each spherical triangle is: I=4 n , n=1, 2, 3..., n is the number of layers, n=1 is the first layer, n=2 is the second layer, and so on;

[0072] According to the surface area of ​​the earth, the cell area F obtained by subdividing each layer can be calculated. k See Table 1.

[0073] Table 1. The ...

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Abstract

The invention relates to a partitioning method of equal-area global discrete grids based on a warp and a weft. The partitioning method comprises the following steps of: coinciding six top points connected with a regular octahedron in a sphere with two poles, the equator, a main meridian, a 90-degree meridian, a 180-degree meridian and a 270-degree meridian, obtaining eight spherical triangles by carrying out gnomonic projection on the regular octahedron on a spherical surface, and finishing initial partitioning of the spherical surface; firstly equally dividing each spherical triangle by an arc on which the weft is located, obtaining a spherical sub-triangle and a spherical trapezoid, then equally dividing the obtained spherical sub-triangle and the spherical trapezoid by the arc on which the weft and the warp are located, obtaining one spherical sub-triangle and three spherical trapezoids, and finishing first-layer partitioning; equally dividing each spherical trapezoid by the arc on which the weft and the warp are located; partitioning the spherical sub-triangle into four equal-area parts according to a first-layer partitioning method, and finishing second-layer partitioning, and obtaining sixteen equal-area grid units in all; and carrying out successive recursion partitioning until n-layer partitioning in which a required precision is met.

Description

technical field [0001] The invention relates to a method for subdividing a global discrete grid, in particular to a method for subdividing an equal-area global discrete grid based on latitude and longitude lines. Background technique [0002] With the continuous deepening of research on global issues such as global climate research, global resource management and environmental protection, and global animal and plant ecological monitoring, more and more applications need to be operated on a global scale. At this time, if the data of the spherical or ellipsoid is converted to the plane for processing in the way of map projection, a series of problems will appear: there will be obvious deviations in the calculation of quantities such as length and area, and there will be Problems such as data overlap, fragmentation, and inconsistency in spatial relationships make it impossible to achieve seamless linking of spatial data around the world, and its validity and accuracy have been ...

Claims

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Application Information

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IPC IPC(8): G06F19/00
Inventor 吴慧欣乔长录宋连公朱齐亮郑辉姚建斌张速
Owner NORTH CHINA UNIV OF WATER RESOURCES & ELECTRIC POWER
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