geodetics: Terrestrial coordinate systems and geodetic calculations.

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Precise geographical coordinates (latitude & longitude), with conversion between different reference frames and projections.

Certain distinguished reference frames and grids are given distinct types so that coordinates expressed within them cannot be confused with coordinates in other frames.

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Properties

Versions	0.0.1, 0.0.2, 0.0.3, 0.0.4, 0.0.5, 0.0.6, 0.1.0, 0.1.2, 1.0.0, 1.1.0, 2.0.0, 2.0.0
Change log	changelog.md
Dependencies	array (>=0.1 && <0.6), base (>=4.17 && <5), parsec (>=3.1 && <3.2), Stream (>=0.4.6 && <0.5) [details]
License	BSD-3-Clause
Copyright	Paul Johnson 2018, 2025
Author	Paul Johnson <paul@cogito.org.uk>
Maintainer	Paul Johnson <paul@cogito.org.uk>
Category	Geography
Home page	https://github.com/PaulJohnson/geodetics
Source repo	head: git clone https://github.com/PaulJohnson/geodetics
Uploaded	by PaulJohnson at 2026-01-02T15:12:59Z

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Geodetics

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geodetics-2.0.0.tar.gz [browse] (Cabal source package)
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Readme for geodetics-2.0.0

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geodetics

Haskell library of data types and calculations for positions on planet Earth

This library provides "geodetic" positions. That is, latitude, longitude and altitude on a specified Terrestrial Reference Frame (TRF). The basic TRF is the WGS84, which is the one used by GPS and Google Earth. Others can be added by describing the underlying ellipsoid and the difference in angle and centre with WGS84, and a position in one TRF can be transformed into another. Given two points in the same TRF you can find the shortest distance between them and the bearing from one to the other.

Once you have a geodetic position defined you can project it onto a flat plane, or Grid. At present Transverse Mercator and Oblique Stereographic grids are provided. More can be added by defining new instances of the Grid typeclass: see "AddingProjections.txt" for detais.

The Paths module defines a path as a parametric function of distance that returns a position and a bearing. Given two paths you can find their intersection using a fast iterative algorithm.