CGCS2000

Use this skill for practical reasoning about the China Geodetic Coordinate System 2000.

CGCS2000 is a China-centered geodetic reference framework used widely in surveying, mapping, and domestic GIS workflows. In many GIS tools, the geographic form is commonly represented as EPSG:4490, but real work often also involves projected CGCS2000 variants, especially Gauss-Kruger zone systems.

What This Skill Does

• Explain what CGCS2000 is and when it is the right source or target CRS.
• Distinguish geographic CGCS2000 from projected CGCS2000 variants.
• Identify whether the user likely means EPSG:4490 or a projected China CRS in meters.
• Check for common mistakes involving axis order, units, and false assumptions about "same as WGS84".
• Compare CGCS2000 with WGS84, GCJ-02, and BD-09.
• Recommend whether to keep the data in geographic coordinates or move to a projected CRS for analysis.
• Hand off file-based conversion and batch reprojection steps to qgis when execution is needed.

Standard Workflow