# coordtransform

提供了百度坐标（BD09）、国测局坐标（火星坐标，GCJ02）、和WGS84坐标系之间的转换

Repository: https://github.com/wandergis/coordtransform
Canonical: https://ross.abutalabs.com/products/coordtransform
Homepage: http://wandergis.github.io/coordtransform
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2025-09-28T06:53:27+00:00
Link (homepage): http://wandergis.github.io/coordtransform

## Health v2 (maintenance only)
Score: 52/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 44, release rhythm 35, longevity 100
- inputs: {"age_days": 4074, "days_push": 339, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4645, forks 921 (observed 2026-08-28T04:08:55.547736+00:00)

## What it is
A JavaScript module for converting between Chinese map coordinate systems: Baidu BD-09, GCJ-02 (Mars coordinates), and WGS-84 (GPS). It runs in Node.js and browsers and has Python, Go, and CLI variants.

## Use cases
- convert baidu bd09 coordinates to gcj02
- convert gps wgs84 coordinates for chinese maps
- fix map marker offset when overlaying points on amap or leaflet
- batch transform coordinates between chinese map datums
- convert gcj02 mars coordinates back to wgs84

## When to choose
- you need to align GPS or Baidu SDK locations with Chinese web map tiles like Amap, Tencent, or Baidu
- you want a tiny dependency-free coordinate conversion utility in JavaScript or Python

## When to avoid
- you need general-purpose geodesy or projections beyond the three Chinese coordinate systems
- you need high-precision official transformations for surveying or legal use

## Facets
- artifact type: library
- maturity: stable
- function: geospatial, developer-tools
- domain: web-development
- platform: browser
- tags: coordinate-conversion, bd09, gcj02, wgs84, china-maps, gis, maps, geospatial, nodejs, javascript

## Member repositories
- wandergis/coordtransform (main) score 52
- wandergis/coordTransform_py (sdk) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:55.547736+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:19:31.833502+00:00, confidence not recorded.
  - readme: https://github.com/wandergis/coordtransform (fetched 2026-08-28T04:08:55.547736+00:00, sha 16f11d16eba6)
  - homepage: http://wandergis.github.io/coordtransform (fetched 2026-08-29T09:04:25.164842+00:00, sha 864243c00de0)
  - registry_npm: https://registry.npmjs.org/coordtransform (fetched 2026-08-29T09:04:25.174416+00:00, sha 5c98f7759f06)
- Data as of 2026-08-30T08:39:29.467469+00:00.