Create a new Geographic Coordinate System.

Function Description

New Geographic Coordinate System are supported in the Coordinate System Settings dialog.

Function entrance

  • Home tab-> Data Processing group-> Projection Settings-> Projection Settings window-> Create New Coordinate System->Geographic Coordinate System。
  • Reset Coordinate System..-> Projection Settings Window-> Create in DatasetContext Menu-> Properties-> Coordinate System Options in Workspace Manager New Coordinate System->Geographic Coordinate System。
  • Context Menu- > Attribute item in Map, In the Reset Coordinate System..-> Projection Settings window-> Create New Coordinate of the Layer Properties panel-> Coordinate System option System-> Geographic Coordinate System button.

Operating instructions

  1. On the Coordinate System Settings dialog, click the Create New Coordinate System Drop-down Button to select the Geographic Coordinate System. The Custom Geographic Coordinate System dialog box appears.
  2. In the Custom Geographic Coordinate System dialog box, the Parameter Description to be set is as follows:
    • Name: Sets the Custom Geographic Coordinate System name.
    • Datum: Datum is established based on the ellipsoid of the earth. It determines the position of the ellipsoid of the earth relative to the center of the earth, provides a reference frame for the measurement of surface features, and determines the origin and direction of the longitude and latitude lines of the earth surface. In short, it is the positioning and orientation of the ellipsoid. Each country or region has its own datum. The two commonly used datums in China include Beijing 54 coordinate system (Beijing1954) and Xi'an 80 coordinate system (Xian1980).
      • System predefined Datum: Click the Drop-down Button on the right to pop up the Datum list. You can select a system predefined Datum type from the drop-down list. If you select Datum provided by the system, parameters such as Reference Spheroid and ellipse semi-major axis/flattening are fixed and cannot be edited.
      • Custom Datum: The user can enter a new name in the text box on the right side of the label as the name of the custom Datum, which can customize Parameters such as Reference Spheroid and ellipse semi-major axis/flattening. Customized Datum supports saving. After the setting name is saved, you can directly select to use it in the drop-down list next time.
    • Reference Spheroid: The surface of the ellipsoid of the earth is a regular mathematical surface expressed by data formulas. In surveying and mapping, the surface of the ellipsoid of the earth is often used to replace the natural surface of the earth. The application of Spheroid Parameter "should be based on the specific situation of each country or region to select the appropriate ellipsoid of the earth. The ellipsoids commonly used in China include Krasovsky 1940 (equatorial radius is 6378245.0 meters, oblateness is 1/298.3), International 1975 (equatorial radius is 6378140, oblateness is 1/298.257), etc.
      • System-predefined Reference Spheroid: Click the Drop-down Button on the right to pop up the Reference Spheroid list. You can select a system-predefined Reference Spheroid type from the drop-down list.
      • Custom Reference Spheroid: The user can enter a new name in the text box to the right of the label as the name of the custom Reference Spheroid. You can customize the specific values of Semimajor Axis and oblateness.
    • EPSG Code: At present, different combinations of ellipsoid and Projected Coordinate System correspond to different ID codes, which are called EPSG Code in EPSG. It represents information such as a specific ellipsoid, unit, Geographic Coordinate System, or Projected Coordinate System. Its code ID will be different because of different Projected Coordinate System and different Geographic Coordinate System.
    • Prime Meridian: Prime Meridian defines the starting position of the abscissa of the Geographic Coordinate System. In most Coordinate Systems, Center Meridian is the line of longitude passing through Greenwich, London, England (longitude 0). Click the Drop-down Button on the right to bring up the Prime Meridian list, where you can select one of the system-predefined Prime Meridian types.
  3. Complete the above Parameter Settings to finish creating a new Geographic Coordinate System.

Related topics

Projection Settings

Create a new Projected Coordinate System.

Created by EPSG Encoding coordinate system

Set Planar Coordinate System.

Set Projected Coordinate System.

Setting Up the Geographic Coordinate System