ClawHub

cgcs2000国家2000坐标系

Prompts

Explain and work with the CGCS2000 coordinate reference system for China geospatial workflows, including EPSG:4490 interpretation, projected CRS selection, Gauss-Kruger zoning, axis/unit checks, and comparison with WGS84, GCJ-02, and BD-09. Use when the user asks about CGCS2000, 中国大地2000, EPSG:4490, 国家2000坐标系, 高斯-克吕格分带, 坐标系选择, or CGCS2000 conversion guidance.

Install

openclaw skills install cgcs2000

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

  1. Confirm the actual input form:
    • longitude/latitude in degrees
    • projected easting/northing in meters
    • map-app coordinates that may actually be GCJ-02 or BD-09
  2. Ask whether the user needs:
    • storage or exchange
    • web display
    • engineering, surveying, or measurement
    • file-based reprojection
  3. State the exact CRS level being discussed:
    • CGCS2000 datum/reference frame
    • EPSG:4490 geographic CRS
    • projected CGCS2000 CRS with zone/projection details
  4. Validate units and order before recommending conversion.
  5. If the task needs meters, recommend the exact projected CRS rather than only saying "CGCS2000".

Decision Rules

  • Use EPSG:4490 when the data is truly geographic CGCS2000 longitude/latitude in degrees.
  • For engineering, cadastral, measurement, or local analysis work, prefer the correct projected CGCS2000 CRS in meters.
  • Do not say "CGCS2000" alone when the task requires a projected CRS; include zone/projection details.
  • Do not treat GCJ-02 or BD-09 as standard CGCS2000 coordinates.
  • Do not assume consumer-map coordinates in China are raw CGCS2000 or raw WGS84.
  • If the source is unknown, explicitly call out datum/projection uncertainty before suggesting a transformation.

Common Cases

The user says "CGCS2000 coordinates"

Interpret carefully:

  • It may mean EPSG:4490 longitude/latitude in degrees.
  • It may mean a projected CGCS2000 coordinate system in meters.
  • It may be shorthand from a local data specification that still requires the exact EPSG or projection name.

The user wants to compare CGCS2000 and WGS84

  • They are close for many practical GIS use cases, but they are not interchangeable by definition in every precise workflow.
  • If regulatory, survey, or engineering accuracy matters, keep the stated source datum and use the required official CRS.
  • If the task is generic storage or API exchange, explain whether the downstream system expects CGCS2000 or WGS84 explicitly.

The user has China map coordinates from an app

  • First check whether the source is actually GCJ-02 or BD-09.
  • Do not label app-map coordinates as CGCS2000 without evidence.
  • If the request is about web maps or app SDKs, mention offset-system ambiguity early.

The user wants projected analysis

  • Ask for the area of use and the current CRS.
  • Recommend the exact projected CGCS2000 CRS with units in meters.
  • If the user only has files and wants execution, use qgis.

What To Return

  • The interpreted source CRS, with exact name or EPSG when possible.
  • Whether the coordinates are likely geographic degrees or projected meters.
  • Whether EPSG:4490 is appropriate, or whether a projected CGCS2000 CRS is needed instead.
  • Any risk that the data is actually GCJ-02 or BD-09.
  • A concrete next step for reprojection, exchange, or validation.

When Not To Use

  • Reverse geocoding or address lookup: use geocode.
  • QGIS file-based processing or batch reprojection: use qgis.
  • General CRS comparison across many systems when CGCS2000 is not the focus: use project.
  • GPS-only WGS84 validation with no China-specific CRS question: use wgs84.

OpenClaw + ClawHub Notes

  • Keep examples generic and standards-based.
  • Do not hardcode private datasets, machine paths, credentials, or proprietary basemap assumptions.
  • For clawhub.ai publication, keep examples reproducible and version/changelog updates semver-driven.

Reference Docs In This Skill

  • Read {baseDir}/references/cgcs2000-reference.md for quick comparison points, projected-workflow guidance, and common failure cases.
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