New Geographic Coordinate System

Feature Description

The Coordinate System Settings dialog box supports creating new geographic coordinate systems.

Feature Entry

  • Image Panel->Dataset Context Menu->Properties->Coordinate System item in properties panel->Reset Coordinate System... Button->Coordinate SystemSettings Dialog->New Coordinate System Dropdown->Geographic Coordinate System Button.
  • Map Context Menu->Properties->Coordinate System option in MapsProperties Panel->Reset Coordinate System... Button->Coordinate SystemSettings Dialog->New Coordinate System Dropdown->Geographic Coordinate System Button.

Steps

  1. Select Geographic Coordinate System from New Coordinate System dropdown in Coordinate System Settings dialog to open Custom Geographic Coordinate System dialog.
  2. Parameter descriptions in the dialog:
    • Name: Specifies the name of custom geographic coordinate system.
    • Datum: A datum defines the reference frame for Earth's surface measurements based on a spheroid model. Commonly used datums in China include Beijing1954, Xian1980, and China2000. Select from the dropdown, or choose <UserDefined> if predefined options are insufficient.
    • Reference Spheroid: Mathematical models approximating Earth's shape. Common spheroids in China include Krasovsky1940 (Semimajor axis: 6,378,245.0m, Flattening: 1/298.3) and International1975 (Semimajor axis: 6,378,140m, Flattening: 1/298.257). Automatically populated based on selected datum, editable only when datum is <UserDefined>.
    • Semimajor Axis: Auto-populated with spheroid selection. Editable when reference spheroid is <UserDefined>.
    • Spheroid Flattening: Auto-populated with spheroid selection. Editable when reference spheroid is <UserDefined>.
    • EPSG Code: Unique identifier in EPSG Geodetic Parameter Registry representing specific coordinate system configurations.
    • Prime Meridian: Defines the origin longitude (0°). Typically Greenwich. Select from dropdown list of predefined meridians.
    • Projection Height: Sets the height parameter for projection.
  3. Complete parameters to create geographic coordinate system.

Related Topics

Coordinate System Settings

New Projected Coordinate System

Create Coordinate System by EPSG Encoding