proj地理坐标系投影转换

Explain, compare, and choose geographic coordinate reference systems and map projections, including CRS selection, EPSG codes, datum differences, axis order,...

Security Scan

This is an instruction-only CRS/projection advisory skill whose requirements, instructions, and scope are consistent with its stated purpose and it does not request credentials or install code.

Purpose & Capability

Name and description match the SKILL.md and reference content: the skill is purely advisory about CRSs, projections, EPSG codes, datum/axis/unit issues and recommends tools (e.g., QGIS) for execution. It does not request unrelated permissions or credentials.

Instruction Scope

Runtime instructions stay within the advisory scope: they explain workflows, checklist items, common rules, and explicitly defer deterministic file operations to external GIS tools. The skill does not instruct reading arbitrary system files or sending data to unknown endpoints.

Install Mechanism

No install spec and no code files — instruction-only — so nothing is written to disk or downloaded during install. This is the lowest-risk model and matches the skill's advisory purpose.

Credentials

No required environment variables, credentials, or config paths are declared or referenced. The skill does not ask for secrets or unrelated service tokens.

Persistence & Privilege

always:false and no install persistence; the agent policy allows implicit/autonomous invocation (allow_implicit_invocation true) which is normal for skills. If you are concerned about any skill acting without prompts, note this setting but it is not unusual or excessive here.

Assessment

This skill is an advisory-only tool for choosing and explaining coordinate systems and projections — it does not perform file conversions or request secrets. Before enabling: understand it will give recommendations (and may autonomously be invoked by the agent if allowed), but you must use a GIS tool (e.g., QGIS, PROJ, GDAL) to run bulk reprojections or handle local files. Avoid pasting private coordinate datasets or credentials into chat; verify any recommended EPSG, datum shifts, or transformation parameters in your own GIS software when accuracy matters.

Project

Use this skill for geographic coordinate system and projection questions.

Scope

• Explain what a CRS/projection is and why it matters.
• Compare common systems such as EPSG:4326, EPSG:3857, UTM zones, CGCS2000, GCJ-02, and BD-09.
• Recommend a target CRS based on the task: storage, web map display, measurement, analysis, or exchange.
• Review conversion plans and call out likely mistakes such as swapped axis order, wrong units, or datum mismatch.

Workflow

1. Identify the source coordinate system, target coordinate system, and the actual job to be done.
2. State whether the user needs a geographic CRS, projected CRS, or a provider-specific offset system.
3. Call out the important differences: datum, units, axis order, extent, and whether the transform is exact or approximate.
4. Give a concrete recommendation with an EPSG code or named system when possible.
5. If the request involves local files or batch conversion, hand off execution details to qgis.

Answer Checklist

• Name the source and target CRS explicitly.
• State units clearly: degrees vs meters.
• Mention whether the CRS is suitable for measurement, display, storage, or exchange.
• Warn when web map tiles use EPSG:3857 but input data is EPSG:4326.
• Warn that GCJ-02 and BD-09 are offset systems, not drop-in replacements for standard global CRS definitions.
• If accuracy matters, state whether a datum shift or local transformation model is required.

Common Rules

• Prefer EPSG:4326 for interoperable storage and API exchange unless another CRS is required.
• Prefer a projected CRS in meters for distance, area, and buffering.
• Prefer the correct local projected CRS over Web Mercator for engineering or survey-style measurement.
• Do not guess a UTM zone from country alone; derive it from longitude and hemisphere.
• Do not assume all software uses the same axis order for EPSG:4326; some APIs expect lon,lat, others advertise lat,lon.

When Not to Use

• Reverse geocoding or coordinates-to-address lookup: use geocode.
• Deterministic GIS execution on files: use qgis.
• CesiumJS globe rendering or camera/data-layer code: use cesium.
• Navigation routing, turn-by-turn directions, or POI reviews.

OpenClaw + ClawHub Notes

• Keep examples generic and portable. Do not hardcode private datasets, machine paths, or tokens.
• Prefer standards-based names and EPSG identifiers over vendor-specific jargon.
• For clawhub.ai publication, keep examples reproducible and changelog/version updates semver-driven.

Reference Docs In This Skill

• Read {baseDir}/references/common-systems.md when you need quick guidance on common CRS and projection tradeoffs.