India HS code-based product analysis

List of contents of this article:

• 1, What are the commonly used coordinate systems in China
• 2, Types of common coordinate systems
• 3, What are the common coordinate systems in surveying and mapping projects and how to choose them? What are the choices of the central meridian...
• 4, What are the current coordinate systems in China
• 5, Measure the five commonly used coordinate systems
• 6、What are the three types of coordinate systems

What are the commonly used coordinate systems in China

1. The coordinate systems commonly used in China include 2000 national geocoordinates Department, 1980 Xi'an coordinate system, 1954 background coordinate system, etc.

2, b. The orientation of the ellipsoid is not very clear. The short semi-axis of the ellipsoid does not point to the internationally common CIO pole nor to the JYD pole currently used in China. Refer to the systematic inclination of the elliptical plane and the earth level surface of China in the west high and low in the east.

3. The three commonly used coordinate systems of China's geographical data are: Beijing 5 Xi'an 80 and WGS-84.

4. There are the following four measurement coordinate systems used in China: Beijing 54 coordinate system Xi'an 80 coordinate system: The earth origin of this coordinate system is located in Yongle Town, Jingyang County, Shaanxi Province in central China, about 60 kilometers northwest of Xi'an City.

5. The geodetic coordinate system commonly used in China mainly includes the following: 2000 national geodetic coordinate system: This coordinate system is high-precision, dynamic, multi-scale and multi-purpose, which can meet the needs of China's modern geodesy, geophysics, meteorology, navigation and other national economic construction and social development.

Types of common coordinate systems

Coordinate systems are divided into: plane right-angle coordinate system, polar coordinate system, column coordinate system. The right-angled coordinate system (Cartesian coordinate system) is based on two vertical numerical axes, and a origin (0, 0 is set at the intersection of the numerical axis. The positive direction and length of the coordinate axis and the angle between the coordinate axis can be set arbitrarily.

I know: world coordinate system, camera coordinate system, image coordinate system. In the measurement environment, a reference coordinate system is required to describe the position of the camera and the measured object, which is called the world coordinate system.

Mathematical right-angled coordinate system;Cylindrical coordinate system; spherical coordinate system; polar coordinate system; in geodesy, there are also geodestic coordinate systems (retated by longitude and latitude), Gaussian plane right-angle coordinate system, etc.; in geographic information system, there are raster coordinate systems, octal tree coordinate systems, etc.; in computers, there are screen coordinate systems, etc.

Common coordinate systems include: spatial geod coordinate system, spatial right-angled coordinate system, and plane right-angled coordinate system. A vertical line in the middle of each 6-degree band is the central meridian.

Beijing 54 coordinate system (BJZ54) Beijing 54 coordinate system is a center-centric earth coordinate system. A point on the earth can be positioned with longitude L5 latitude M54 and earth height H54. It is a coordinate system based on the Krasovsky ellipsoid and generated after local flat difference.

What are the common coordinate systems in surveying and mapping projects and how to choose them? What are the choices of the central meridian...

Geocentric coordinate system, reference center coordinate system and local independent coordinate system. Geocentric coordinate system The geocentric coordinate system is related to an ellipsoid element of the earth. Generally, it is required to be an ellipsoid that is most closely related to the global geodes plane. The center of the global ellipsoid can generally be considered to coincide with the center of mass of the earth.

Basic concept: topographic map coordinate system: China's topographic map adopts the Gauss-Krüg plane right-angle coordinate system. In this coordinate system, the horizontal axis: the equator, represented by Y; the vertical axis: the central meridian, represented by X; the coordinate origin: the intersection of the central meridian and the equator, represented by O.

On the Gaussian projection plane, the projection of the central meridian and the equator is two perpendicular to each other.

The conventional conversion of geode coordinates (BLH) to plane right-angled coordinates (XYZ) should first determine the conversion parameters, that is, elliptical parameters, band division standards (3 degrees, 6 degrees) and the lotitude of the central meridian. Ellipsical parameters refer to what kind of elliptical benchmark is adopted by the plane right-angled coordinate system, corresponding to different lengths and short axes and flatness.

The coordinate origin O of the geocentric coordinate system is set in the center of mass of the earth, which is represented by the three axes of X, Y and Z perpendicular to each other. The X axis coincides with the intersection of the first meridian and the equatorial plane, and is positive to the east; the Z axis coincides with the rotation axis of the earth, and the north is positive; the Y axis is vertical to the XZ plane. Become the right hand system.

The Gaussian plane right-angle coordinate system takes the intersection of the equator and the central meridian as the coordinate origin O. The direction of the central meridian is the X axis, and the north direction is the positive value.The equatorial projection line is the Y axis, and the east direction is positive. The quadrants are arranged clockwise I, II, III, IV.

What are the coordinate systems in China at present

1. There are the following four measurement coordinate systems used in China: Beijing 54 coordinate system Xi'an 80 coordinate system: the earth origin of this coordinate system is located in Shaanxi Province in the central part of China Yongle Town, Jingyang County, is located about 60 kilometers northwest of Xi'an City.

2. WGS84 coordinate system, long axis 637813000m, short axis 635675314, flatness 1/29257223563.

3. The coordinate system is divided into: plane right-angled coordinate system, polar coordinate system and column coordinate system. Right-angled coordinate system (Cartesian coordinate system) is based on two vertical number axes, and an origin (0, 0) is set at the intersection of the number axis. The positive direction and length of the coordinate axis and the angle between the coordinate axes can be set arbitrarily.

Five commonly used coordinate systems for measurement

1. Right-angled coordinate system (Cartesian coordinate system). Based on two vertical numerical axes, an origin (0, 0) is set at the intersection of the numerical axis. The positive direction and length of the coordinate axis and the angle between the coordinate axis can be set arbitrarily. Use a set of ordered number pairs (x, y) to represent the position of a point. Cylindrical coordinate system.

2. The coordinate system commonly used in photographic measurement is as follows: image plane coordinate system (o-xy): a right-angled coordinate system that represents the position of the image point in the image plane.Image space coordinate system (s-xyz): the spatial right-angled coordinate system that represents the position of the image point in the image square space.

3. Geocentric coordinate system, reference center coordinate system and local independent coordinate system. Geocentric coordinate system The geocentric coordinate system is related to an ellipsoid element of the earth. Generally, it is required to be an ellipsoid that is most closely related to the global geodes plane. The center of the global ellipsoid can generally be considered to coincide with the center of mass of the earth.

What are the three types of coordinate systems

The coordinate system is divided into: plane right-angled coordinate system, polar coordinate system, and column coordinate system. Polar coordinates refer to a coordinate system composed of poles, polar axes and polar diameters in the plane. Take a point O on the plane, which is called the pole.A Ray Ox Is Drawn From O, Which Is Called The Polar Axis. Coordinates, mathematical nouns.

Common coordinate systems include: spatial right-angle coordinate system, column coordinate system and spherical coordinate system. The coordinate system is a commonly used auxiliary method in science. Commonly, there are linear coordinate system and plane right-angle coordinate system, in order to explain the position of the point, the speed of movement, the direction, etc.

According to the implementation year: 1954 Beijing coordinate system, 1980 Xi'an coordinate system. It is mainly used to confirm the coordinates and direction of the house by CAD drawings of engineering construction and construction. By region or function: there are national standard coordinate systems and local independent coordinate systems. It is mainly used for the production, research and calculation of geographical drawings. It is also often used in the teaching of geography.