National Basic Scale Topographic Map and sub-Calculation

2.1 Topographic Map type

1. Topographic Map type

Topographic Maps are divided into two categories based on different departments and service objects of organization and surveying:

A. National Basic Scale Topographic Map:

The State Administration of Surveying and Mapping organizes surveying and mapping in a unified manner as basic materials for national economic construction, national defense and scientific research.

B. Large Scale Topographic Map:

The planning, design, and specific construction requirements of a department or organization for a specific project are measured in a small scope.

2. Features of national basic topographic maps

(1) unified coordinate system and Elevation System

(2) complete scale series and split Number System

(3) Unified Specifications and diagrams

3. Features of large scale topographic maps of small areas for engineering use

(1) There is no strictly unified geocoordinate system and Elevation System

(2) There is no strictly unified topographic map scale series and split Number System

(3) some supplementary provisions can be made on the ing specifications and diagrams of the National ing department in light of the special requirements of engineering planning and construction.

Functions of national basic topographic maps

If the scale is different, the precision and details are different, and the purpose is different.

To Large-Scale Topographic Map

, Medium-scale Topographic Map

Small Scale Topographic Map

2.3 national basic topographic map part No.

1.--Scale Topographic Map

From the equator to the North and South Poles every 4 ° into a column, a total of 22 columns, using a, B, c, d ,..., V indicates that a row is divided into 60 rows at intervals of 6 ° from the west to the east starting from 180 ° longitude, with 1, 2, 3 ,..., 60.

The column is in the front, the row is in the rear, and the-connection is used in the middle. For example, Column (10) -- row (50) represents a J-50.

2. Area No. of A--Scale Topographic Map

Based on the topographic map of, the terrain is divided by 3 ° longitude difference and 2 ° latitude difference. The numbering method is from left to right. From top to bottom, add the Latin letters A, B, C, and D to the back of. Like J-50-A.

3. Area No. of A--Scale Topographic Map

Based on a topographic map with a scale of to, the terrain is divided by a longitude deviation of 1 ° 30' and a latitude difference of 1 °. The numbering method is to add the numbers [1] to [16] from left to right, and from top to bottom to the back of the map. Such as J-50-[5]. (The old expression is to add lowercase Latin letters a, B, c, d. Such as J-50-A-b after .)

4. Area Number of the topographic map at a scale

On the basis of a topographic map of, it is divided by a longitude deviation of 30' and a latitude difference of 20. The numbering method is from left to right. From top to bottom, the numbers 1 to 144 are used to add them to the back of the map. Like J-50-6.

5. Area No. of a 10--Scale Topographic Map

On the basis of a topographic map, it is divided by the longitude difference 15' and latitude difference 10. The numbering method is from left to right. From top to bottom, add the Latin letters A, B, C, and D to the back of the graph. Like J-50-5-B.

6. Part Number of the Scale Topographic Map at. 50 thousand

On the basis of a topographic map, it is divided by the longitude deviation of "and the latitude difference. The numbering method is to add Arabic numerals 1, 2, 3, and 4 from left to right after the graph. Like J-50-5-B-2.

7.--Scale Topographic Map

Based on the topographic map of, it is divided by a longitude deviation of "and a latitude difference. The numbering method is from left to right, from top to bottom with the Arabic numerals (1), (2), (3 ),... And (64) after. Like J-50-5-(5 ).

2.4 Calculation of topographic map part numbers

1. Calculate the image number based on the longitude and latitude of a certain place

Example 1: If the geographic coordinates of a certain place are known to be "hour = 31 ° 19' 30" N, λ = 119 ° 22' 30 "E", find the number of the topographic map at a scale of.

Solution steps: (1) calculate the number of the topographic map at the scale of (H-50 ).

Number of columns = 31 ° 19' 30 "/4 ° = 8

Number of rows = 30 + 119 ° 22 '30 "/6 ° = 50

(2) Calculate the longitude and latitude of the million graph contour.

Latitude of the North graph profile = 8*4 ° = 32 ° N

Latitude = (8-1) x 4 ° = 28 ° N

Longitude of the East graph profile = 50*6 °-180 ° = 120 ° E

Longitude = 120 °-6 ° = 114 ° E

(3) Draw a sketch with a topographic map number of and grade it with 16.

(4) according to the given latitude and longitude to find the topographic map of (H-50-[4]).

2. Calculate the longitude and latitude of a certain place based on the figure number.

Example 2: the longitude and latitude of a chart is known as a H-50-6-A.

Solution steps: (1) determine the scale of the graph based on the graph number ).

(2) Calculate the longitude and latitude of a million graph contour based on the figure number.

Latitude of the North graph profile = 8*4 ° = 32 ° N

Latitude = (8-1) x 4 ° = 28 ° N

Longitude of the East graph profile = 50*6 °-180 ° = 120 ° E

Longitude = 120 °-6 ° = 114 ° E

(3) Draw a sketch of a-144-Topographic Map and grade it. Find the H-50-6 and Its latitude and longitude.

(4) divide the topographic map of to 4 equal portions. Find out the H-50-6-A and ask for its latitude and longitude.