Skill: jvy/cgcs2000 (version 1.0.0)

--- name: cgcs2000 description: 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. metadata: openclaw: emoji: "🇨🇳" --- # 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.


Security scan verdicts — ClawScan: clean | static analysis: clean | VirusTotal: clean | SkillSpector: clean (LOW)