# chrisveness/geodesy

Libraries of geodesy functions implemented in JavaScript

Repository: https://github.com/chrisveness/geodesy
Canonical: https://ross.abutalabs.com/products/geodesy
Homepage: http://www.movable-type.co.uk/scripts/geodesy-library.html
Language: JavaScript
License: MIT
License Family: permissive
Topics: geodesy, latitude, longitude, distance, bearing, destination, haversine, vincenty, rhumb, ellipsoid, datum, trf, n-vector, wgs84, utm, mgrs, javascript
Last push: 2024-07-10T16:54:06+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4480, "days_push": 784, "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 1227, forks 207 (observed 2026-08-28T04:04:03.365237+00:00)

## What it is
A JavaScript library of geodesy functions covering distances, bearings, and coordinate conversions on spherical and ellipsoidal earth models. It includes UTM/MGRS and OSGB grid references, historical datum conversions, and modern terrestrial reference frame conversions.

## Use cases
- calculate distance between two latitude/longitude points
- compute bearing and destination point from lat/lon
- convert lat/lon to UTM or MGRS coordinates
- convert between datums like NAD83, OSGB36, or ITRF2014
- work with n-vector geodesy representations
- parse and format degrees minutes seconds coordinates
- convert geodetic coordinates to cartesian x/y/z

## When to choose
- you need accurate geodesic calculations in JavaScript for browser or Node.js
- you need coordinate conversions between WGS84, UTM, MGRS, or national grids
- you want well-documented, language-agnostic geodesy algorithms you can port
- you need both simple spherical and high-accuracy ellipsoidal earth models

## When to avoid
- you need geospatial features beyond coordinate math such as routing, geocoding, or map rendering
- you work in a language other than JavaScript and cannot port the algorithms
- you need a full GIS toolkit with projections beyond the ones covered
- you require high-performance bulk processing of millions of coordinates

## Facets
- artifact type: library
- maturity: stable
- function: geospatial, math, sdk
- domain: developer-tools
- platform: browser, cross-platform
- tags: geodesy, latitude-longitude, haversine, vincenty, utm, mgrs, datum-conversion, n-vector, wgs84, coordinate-conversion, geospatial, maps, algorithms, javascript, nodejs

## Member repositories
- chrisveness/geodesy (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:03.365237+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 2026-08-30T06:15:14.795505+00:00, confidence not recorded.
  - readme: https://github.com/chrisveness/geodesy (fetched 2026-08-28T04:04:03.365237+00:00, sha 82e32c9dcc28)
  - homepage: http://www.movable-type.co.uk/scripts/geodesy-library.html (fetched 2026-08-29T12:22:57.184257+00:00, sha bee6fdd43123)
  - registry_npm: https://registry.npmjs.org/geodesy (fetched 2026-08-29T12:22:57.187551+00:00, sha af4c72c34ab0)
- Data as of 2026-08-30T08:39:29.467469+00:00.