geodetics

Terrestrial coordinate systems and geodetic calculations.

https://github.com/PaulJohnson/geodetics

LTS Haskell 24.27:1.1.0
Stackage Nightly 2026-01-07:2.0.0
Latest on Hackage:2.0.0

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BSD-3-Clause licensed and maintained by Paul Johnson
This version can be pinned in stack with:geodetics-2.0.0@sha256:ad8b27b48ab5a2a97403b71bb8923dafaf0c13c8b527eba0b65e9e2319a31b41,2761

Module documentation for 2.0.0

Depends on 4 packages(full list with versions):
array, base, parsec, Stream

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, Polar Stereographic 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.

Changes

Release Notes

Version 0.0.2: Tided up cabal file and removed spurious dependency on Parsec.

Version 0.0.3: Updated for Haskell Platform 2014.2.0.0 and GHC 7.8.3. Fixed some minor documentation issues.

Version 0.0.4: Updated for Dimensional 1.0.

Version 0.0.5: Fixed bug in Monoid instance for Helmert. Created Semigroup instance for Helmert.

Version 0.0.6: Prevent attempted building on GHC 7.8 (it doesn’t work) and fix the build on 7.10 with a conditional semigroups dependency

Version 0.1.0: Updated for Dimensional 1.3 and GHC 8.6.

Version 0.1.1: Fixed bug #15: for a point p, groundDistance p p returned NaN

Version 0.1.2: Fixed bugs #16 and #17: Unicode PRIME and DOUBLE PRIME now allowed in position strings, and the degree symbol is allowed for decimal degrees.

Version 1.0.0

  • Removed dependency on Dimensional library. This is a breaking change: hence the major version bump.

  • Fixed bug #18 (and #19).

Version 1.1.0

  • Dropped a redundant Ellipsoid constraint on antipode.

  • Added functions showGeodeticLatLong, showGeodeticSignedDecimal, showGeodeticNSEWDecimal, and showGeodeticDDDMMSS.

  • Fixed a few minor bugs in the readGroundPosition and the Geodetics.LatLongParser.

  • Added Universal Transverse Mercator (UTM) grid, with both UTM and MGRS grid references

Version 2.0.0

This version has breaking changes relative to version 1.1.0.

  • Added PolarStereographic projection with UPS grid

  • Moved MGRS grid types and functions to its own module and extended it to include UPS gridpoints.

  • Replaced the UtmGridUnit type with a more general GridUnit type in Geodetics.Grid.

  • Provided standalone Parsec parsers for MGRS and UTM grid references.

  • Modified code formatting to have consistently 2 spaces per indent level.