Some standard content:
National Standard of the People's Republic of China
Geography
1 Subject content and scope of application
1.1 Subject content
Geographic grid
Geographic grid
Geographic grid| |tt||网
GB 12409-90
This standard specifies the rules and codes for the division of geographical grid systems, which are used to identify resources and environmental information related to geographical spatial distribution and ensure their existence. storage, statistics, analysis and exchange to achieve information sharing. 1.2 Scope of application
This standard is applicable to resources and environmental information that is distributed in a planar manner and uses a grid as a unit of measurement. Among them, the 10° ) resources and environmental information within the scope. The Cartesian coordinate grid system is mainly suitable for representing resource and environmental information required for engineering planning, design, construction and other applications in land and offshore areas.
In order to realize information sharing nationwide, it is stipulated that the 4° × 6° grid system should be used when exchanging information among various domestic systems. Any of the above three systems can be used within the system or for international exchanges. 2 Terms
2.1 Geographic grid
The geographical grid is a grid formed by dividing the earth's surface according to certain mathematical rules. 2.210°×10° grid system
A multi-level geographical grid system composed of a basic grid with a latitude difference of 10° and a longitude difference of 10°. 2.34°×6° grid system
A multi-level geographical grid system composed of dividing Portugal based on the latitude difference of 4° and the longitude difference of 6°. 2.4 Cartesian coordinate grid system
is a multi-level geographical grid system formed by projecting the earth's surface area onto a plane according to mathematical rules, and then dividing the surface area according to a certain vertical and horizontal coordinate spacing and a unified coordinate origin. 2.5 Grid unit
is a basic grid of a certain level of grid in the grid system. Side lengths vary depending on the grid level in which they are located. 2.6 km grid
In the Cartesian coordinate grid system, the vertical and horizontal coordinate intervals are each 1km apart. 3 Design principles of geographical grid
3.1 Scientificity
The geographical grid is divided according to the quadrants of the earth, latitude and longitude or rectangular coordinates. The three grid systems can be converted into each other and have a strict mathematical basis.
National Chemistry Technical Supervision Kitchen 1990-06-23 Approved 1991-05-01 Implementation
205
3.2 Systematic
GB 12409---90||tt ||The levels of the three grids are in a certain proportional relationship, forming a complete series, which is convenient for forming a regional, national or global grid system.
3.3 Practicality
The grid division fully considers the needs of different users and the current surveying and mapping foundation, and designs three systems of multi-level grids to meet different accuracy requirements and facilitate user selection.
3.4 ??Scalability
The grading and coding design of the grid fully considers the needs of development, so that when further subdividing, it can be expanded on the basis of this standard without changing the original division. system.
Grading and coding of geographical grid system
4
4.110°×10° grid system
4.1.1 grading
10°×10 °The grid system is divided into 7 levels according to the side length of the grid. The specific levels are shown in Table 1. Table 1
Grid level
Grid name
Grid unit side length
4.1.2 encoding
1
10° Grid
10°×100
2
5° grid
5°×5°
10°×10° grid system Grading
3
2° grid
2°×2°
The grid code of the 10°×10° grid system is a purely digital code. 4.1.2.110° grid coding
The code of 10° grid is 4 digits, and the structure is as follows; xx
hundreds and ten digits of longitude
ten digits of latitude
Earth quadrant code
Earth quadrant code is shown in Figure 1.
N
7
Red
5
S
Figure 1
Example 1 The latitude of a certain point is 75° N, longitude is 143°E. Then the code of the 10° grid where the point is located is 1714. The global 10° grid code is shown in Table 2.
206
4
1° grid
1×1°
Equator line
5
1° /2 grid
30×30
Greenwich central meridian
6
1°/4 grid
15°×15||tt| |7
1/10 grid
6×6
NE
SE-
sw
NW-||tt| |12409—90
GB
RIR
21889186918671888188218818018 60880882088908298870856086 2088 108 008 08298998998989819901960 80206969096098980981090096888888268
28912691812812822128026 60282620690808028028202828 002880080200000000000000008||tt| |ZI01 g0IgiO1v0gtOIz1oTO1O1601800t 200T 900 001v001800T201T00F001ZI giI gilIf11Sil zi1o11 6011801t 201I 9o1t go1 o1 go 20I io1001NOT
Li9igiie122lto2160i801201901S1O2180302t02 021eeet900
Lifi giSintIntGizibitloUt 60Pi80Pi 2Pl 9OVigOF OVeOnI2Otiot0010| |tt||19919191019160181201151010091AMO MOI MOZ MOE MOY MOS MO9 MOL MO8 MO6MOTAOILAOZLAOELMOFLAOS LMO9 LMOLE0299998968898989882189
09||tt ||O
9609 01119229229
sgss
0000000000001S
00000000
D
0021082282827882288826828211886827182819 18221LI81918ISI817t8I6181Z8II181018L6081808I2081908t S081708IE081Z0810810081 N08FOROO SO
MO MOI MOZ MOE MON MOS MO9 MOL MO8 MOGAOOLMOTLAOZEMOELMOPLMOSLMOMOLI207
4.1.2.The coding of 25°, 2° and 1° grids GB 12409-90
The grid codes are calculated from the single digits of longitude and latitude according to formulas (1), (2) and (3): 5° Grid code = (LO/5) + (LA/5) × 2 + 12° Grid code - (LO/2) × 2 + (LA/2) × 201° Grid code = LO + LA × 10| |tt||In the formula; LO—the single digit of longitude;
LA-
—the single digit of latitude,
The quotient of the division part in the formula is an integer. Example 2 The latitude of a certain point is 65°N and the longitude is 153°E. Then the 5° grid code where the point is located = (3/5) + (5/5) × 2 + 1 - 0 + 2 + 1 = 3 The 2° grid code where the point is located = (3/2) × 2 Ten (5/2) × 20 - 2 + 40 = 42 The 1° grid code where the point is located - 3 + 5 × 10 = 53 In the north latitude and east longitude quadrant, the code distribution of the 5°, 2° and 1° grids See Figure 2. 10°N
90
80
70
BC
91
80
81| |tt||71
60
61
92
82
72
93
82||tt ||188
62
162
63
53
51
152
5N40m
4242
43
30
20
21
10
O'N
O'E||tt ||11
00
01
a2
122
12
02
33
22
23
13
0.2
103
82
00 ~88
1~4||tt ||4.1.2.31/2, 1°/4, 1°/10 grid code 94795
84
185
84
74||tt| |75
64
64
5455
44
44
45
3435
24
14
24
t 25
15
04
04
1.05
5' E
96
86
197
86
187
66
J67
56| |tt||57
46
47
146
78
68
58
T9g||tt ||88
179
68
[69
59
a48
37
36||tt| |38
26.2
2
127
16
06
6
1'grid code|| tt||2° grid code
10° grid code
Figure 2
07
18
08
39| |tt||28
29
19
08
109
10:E
Its grid code consists of latitude and longitude respectively The value of the quantile is calculated according to formulas (4), (5) and (6): 1°/2 grid code two (LOM/30) + (LAM/30) × 2 + 208||tt| |(1)
(2)
(3)
(4)
where: LOM—minutes of longitude;
LAM—latitude of points.
GB 12409-90
1°/4 grid code one (LOM/15) + (LAM/15) × 101°/10 grid code = (LOM/6) + (LAM /6) The quotient of the division part in the ×10 formula is an integer. Example 3: The longitude of a certain point is 143°02\E and the latitude is 75°41'N. Then LOM=02, LAM=41
The 1/2 grid code where the point is located=(2/30)+(41/30)×2+1=0+2+1=3 where the point is The 1°/4 grid code = (2/15) + (41/15) × 10 = 0 + 20-20 The 1°/10 grid code where the point is located = (2/6) ten (41/6 )×10=0+60=604.1.3 combination of grid codes
(5)
(6)
10°×10° grid code consists of 14 digits composition. However, when the grid code level order is otherwise specified in the data file, it can be combined as shown in Figure 3 to shorten the code length:
1°/2 grid
10° grid||tt ||××××
5° grid
X
2° grid
xwww.bzxz.net
x
1 grid
xx
Figure 3
X
1/4 grid
xx
1:/10 grid||tt| |xx
In the above example 3 (longitude 143°02'E, latitude 75°41\N), the 1° grid combination code where the point is located is 171453: the code of the 1°10 grid is 17145360.
4.24°×6° grid system
4.2.1 Grading
4.2.1.1The standard frame of the international 1:1 million topographic map is 4° in latitude and 6° in longitude (see Figure 4). Our country adopts this international standard and based on it, divides the range of other scale topographic maps according to certain latitude and longitude differences, so that the number of sections between adjacent scale topographic maps is an integral multiple (see Table 3) .
209
Scale bar
Figure bat range
Latitude difference
Longitude difference
Quantity relationship between picture frames
Equal divisions Number of rows
Number of equally divided columns
48
44
36°h
32
28
24
20F
16
12
44
84
Table 3
45
90 -
46
GB12409—90
N
M
Ｌ
LK
J
H
G
F
E
D
c
47
96
102| |tt||B
A
108°
Beijing
49
tt4
my country 1:1 million map tiles and numbered Figure 4
2
50
120
Scope range, quantitative relationship and number of rows and columns of maps of different scales 1: 1 million
1 : 500,000 1: 250,000
1: 100,000
4°
6°
1
%
3°| |tt||4
2
2
1°
1°30
16
20
30
144
12
12
150,000
10
15
576
24| |tt||24
51
1*250,000
110,000
5
730m
2304
48
48
2°30m
3'45\
9216
96
96
1:5 Thousands
1'15″
1*52m.5
36864
192
192
1.2 million)||tt| |40
1
36
6
6
Note: 1) The 1/200,000 scale topographic map has changed from the Tujia topographic map scale standard Canceled in the series. However, considering that there are a certain number of 1/200,000 maps in our country’s history, they are still included for reference. 4.2.1.2 The grid classification of this system is based on the basic topographic maps of our country. , divided into 9 levels (see Table 4). The longitude difference of the grid unit side length is equal to the latitude difference. On the ground, it is a trapezoidal area with slightly different areas as the latitude changes. Table 44°×6° Grid System Grading
Grid Level
Grid Unit
Side Length
Scale
1||tt| |30m
2
15
1: 1 million 1: 500,000
Note: 1) See Table 3 Note 1).
210
3
7\.5
1：250,000
3+
1：100,000||tt| |5
1.5
1: 50,000
0.75
1: 25,000
7
o\3||tt| |1：10,000
.8
015
1：5 thousand
99
5
1：200,000 1)
4.2.2 encoding
GB 12409-9
90
4°×6° grid uses a mixed code of numbers and characters, consisting of two parts with a total of 17 digits The structure is as follows: Part 1
Numeric code
Scale character code
X
Xxx
x ??area
Part 2
XXx
XXX
Digital code for grid column number
Digital code for grid row number
Digital code for picture column number
Digital code for picture row number
4.2 .2.1 The first part of the grid code consists of 6 elements with a total of 11 bits, indicating the map frame code where the grid is located. a.
b.
c.
d.
Scale
Code
The 1st digit indicates south or north latitude, south Latitude is represented by "S"; northern latitude is represented by "N". The second digit is a character code, indicating the character code of the latitude zone where the 1:1 million map is located. The specific regulations are shown in Figure 4. The 3rd and 4th digits are digital codes, indicating the digital code of the longitude zone where the 1:1 million map is located. The fifth bit is a character code, indicating the scale code of the topographic map (see Table 5). Table 5 scale code
1#1 million
A
1: 500,000
B
Note: 1) See Note 1 in Table 3).
e.
1：250,000
C
1：100,000
D
1：50,000||tt| |E
1:25,000
F
11,000
G
1:5 thousand
H
The 6th, 7th, and 8th digits are digital codes, indicating the line number of the picture frame. Line numbers are arranged in order from top to bottom starting from 001. The 9th, 10th, and 11th digits are numeric codes, indicating the column number of the picture frame. Column numbers are arranged sequentially starting from 001 from left to right. Figure 5 is a schematic diagram of the division of rows and columns on the 1:1 million map at each level of scale. 1: 200,0001)
z
211
long
03
GB 12409—90
D02
Gate
2
U
Figure 5
024
48
Sequence
002
1
018
036
11
f3
Scale
1/500,000
1/250,000|| tt||00,000
1/5 catties
2.
1
Example 4 - 1:100,000 terrain with map number K-50-113 According to the number of rows and columns in the picture, its code part is NK50D010005.
4.2.2. The second part of the 24°×6° grid code consists of 2 elements and a total of 6 digital codes, indicating the row and column number of a certain grid unit in the corresponding map frame. The first three digits are the row number, and the last three digits are the column number. The row numbers are from top to bottom, and the column numbers are from left to right, starting from 001. Example 5 In the 1:100,000 picture frame whose first part of the code is NJ49D010012, there is a 3\×3\ grid unit with a row number of 024 and a column number of 505. The second part of the code is 024505. This grid The complete code of the unit is NJ49D010012024505. 4.3 Cartesian coordinate grid system
4.3.1 Classification
4.3.1.1 Cartesian coordinate network adopts the 1980 Xi'an coordinate system transverse axis equiangular cylindrical projection (commonly known as Gaussian projection or Gauss-Krüger projection). In order to control the projection deformation, the banding method is adopted. my country's 1:500,000 to 1:25,000 scale topographic maps adopt 6° zoning! :10,000 and 1:5 dry topographic maps adopt 3° zoning.
212
GB 1240990
4.3.1.2The Cartesian coordinate grid system is divided into 9 levels. The specific regulations are shown in Table 6. Table 6 Grading of Cartesian coordinate grid
Grid level
Grid unit
Side length + m
Scale 2)
1000||tt ||2
500
1: 1 million 1: 500,000
Note: 1) See Note 1 in Table 3).
3
250
1: 250,000
4
100
110 squares
5||tt| |50
150,000
6
25
125,000
7
10
1：10,000| |tt||8
5
2.5
15 years
99
200
100
1:20 In case 1)
One scale corresponds to two grid levels. Users can choose according to application needs. 2) The scale of the Cartesian coordinate grid does not uniquely correspond to the grid level. Choose one.
4.3.2 Encoding
The Cartesian coordinate grid adopts determinant encoding, with the row number in front and the column number in the back. Row numbers are from bottom to top and column numbers are from left to right. The entire code is a mixed code consisting of 7 elements and a total of 18 characters and numbers. The structure is as follows: Number of rows in units
Number of columns in kilometers
Xxx
XXXX
XXX
X
XXX||tt| |XXX
Grid column number numeric code
Grid row number numeric code
Grid size character code
a. The first digit uses a character code to indicate southern or northern latitude. Southern latitude is represented by "s" and northern latitude is represented by "N". b. The 2nd, 3rd, and 4th digits are digital codes, indicating the Gauss-Krüger projection zone number where the grid is located. Figure 6 is a schematic diagram of Gauss-Krüger projection banding. The 6°-banded Gaussian projection has a total of 60 bands around the world, and the 3°-banded Gaussian projection has a total of 120 bands around the world. In order to distinguish these two band numbers, the code area for 6° banding is 001 to 060, and the code area for 3° banding is 101 to 220. 1121
Figure 6 Schematic diagram of Gauss-Krüger projection banding The third element and the fourth element together are called the kilometer grid code, both of which are digital codes. The 3rd element is the 5th, 6.7th and 8th bit c.
code indicating the number of rows in kilometers; the 4th element is the 9th, 10th and 11th digits indicating the column in kilometers number. d. The fifth element, the 12th bit, is the character code, indicating the side length of the grid unit (see Table 7). Table 7 Side lengths of Cartesian coordinate grid units and side lengths of code grid units, m
code
500
A
250
B| |tt||100
C
50
D
25
10
5
G||tt ||2.5
H
The 6th element and the 7th element, namely the 13th, 14th, 15th and 16th, 17th and 18th digits represent the generation of a certain grid unit in the kilometer grid. 213
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