Geo::Coordinates::ITM(3pm) User Contributed Perl Documentation Geo::Coordinates::ITM(3pm)NAME
Geo::Coordinates::ITM - Convert coordinates between lat/lon and Irish Transverse Mercator
VERSION
This document describes Geo::Coordinates::ITM version 0.02
SYNOPSIS
use Geo::Coordinates::ITM qw( ll_to_grid grid_to_ll );
my ( $lat, $lon ) = grid_to_ll( $east, $north );
my ( $east, $north ) = ll_to_grid( $lat, $lon );
DESCRIPTION
Convert back and forth between Irish Transverse Mercator grid and WGS84. The conversion code was stolen wholesale from
<http://bit.ly/ZqpUA>.
http://svn.geograph.org.uk/svn/branches/british-isles/libs/geograph
/conversionslatlong.class.php
Nothing is exported by default. The exportable functions are "ll_to_grid" and "grid_to_ll".
INTERFACE
"ll_to_grid"
Convert a latitude, longitude (WGS84) coordinate pair into an ITM easting and northing.
my ( $east, $north ) = ll_to_grid( $lat, $lon );
"grid_to_ll"
Convert an ITM easting, northing pair to a WGS84 latitude, longitude.
my ( $lat, $lon ) = grid_to_ll( $east, $north );
BUGS
Please report any bugs or feature requests to "bug-geo-coordinates-itm@rt.cpan.org", or through the web interface at <http://rt.cpan.org>.
AUTHOR
Andy Armstrong "<andy@hexten.net>"
Code gratefully stolen from <http://bit.ly/ZqpUA>
http://svn.geograph.org.uk/svn/branches/british-isles/libs/geograph
/conversionslatlong.class.php
LICENCE AND COPYRIGHT
Copyright (c) 2009, Andy Armstrong "<andy@hexten.net>".
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.
perl v5.14.2 2012-03-31 Geo::Coordinates::ITM(3pm)
Check Out this Related Man Page
Geo::HelmertTransform(3pm) User Contributed Perl Documentation Geo::HelmertTransform(3pm)NAME
Geo::HelmertTransform
VERSION
1.14
SYNOPSIS
use Geo::HelmertTransform;
my ($lat, $lon, $h) = ...; # from OS map
my $airy1830 = Geo::HelmertTransform::datum('Airy1830');
my $wgs84 = Geo::HelmertTransform::datum('WGS84');
($lat, $lon, $h)
= Geo::HelmertTransform::convert_datum($airy1830, $wgs84,
$lat, $lon, $h);
DESCRIPTION
Perform transformations between geographical coordinates in different datums.
It is usual to describe geographical points in terms of their polar coordinates (latitude, longitude and altitude) referenced to a "datum
ellipsoid", which is used to approximate the Earth's geoid. The latitude, longitude and altitude of a given physical point vary depending
on which datum ellipsoid is in use. Unfortunately, a number of ellipsoids are in everyday use, and so it is often necessary to transform
geographical coordinates between different datum ellipsoids.
Two different datum ellipsoids may differ in the locations of their centers, or in their shape; and there may be an angle between their
equatorial planes or the meridians relative to which longitude is measured. The Helmert Transform, which this module implements, is a
linear transformation of coordinates between pairs of datum ellipsoids in the limit of small angles of deviation between them.
CONVENTIONS
Latitude is expressed in degrees, positive-north; longitude in degrees, positive-east. Heights (ellipsoid) and cartesian coordinates are in
meters.
FUNCTIONS
rad_to_deg RADIANS
Convert RADIANS to degrees.
deg_to_rad DEGREES
Convert DEGREES to radians.
geo_to_xyz DATUM LAT LON H
Return the Cartesian (X, Y, Z) coordinates for the geographical coordinates (LAT, LON, H) in the given DATUM.
xyz_to_geo DATUM X Y Z
Return the geographical (LAT, LON, H) coordinates for the Cartesian coordinates (X, Y, Z) in the given DATUM. This is an iterative
procedure.
convert_datum D1 D2 LAT LON H
Given geographical coordinates (LAT, LON, H) in datum D1, return the corresponding coordinates in datum D2. This assumes that the
transformations are small, and always converts via WGS84.
datum NAME
Return the datum of the given NAME. Currently implemented are:
Airy1830
The 1830 Airy ellipsoid to which the British Ordnance Survey's National Grid is referenced.
Airy1830Modified
The modified 1830 Airy ellipsoid to which the Irish Grid (as used by Ordnance Survey Ireland and Ordnance Survey Northern Ireland);
also known as the Ireland 1975 datum.
WGS84
The global datum used for GPS.
SEE ALSO
A guide to coordinate systems in Great Britain, http://www.gps.gov.uk/guidecontents.asp
Making maps compatible with GPS, http://www.osni.gov.uk/downloads/Making%20maps%20GPS%20compatible.pdf
AUTHOR AND COPYRIGHT
Written by Chris Lightfoot, team@mysociety.org
Copyright (c) UK Citizens Online Democracy.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl v5.12.4 2011-08-29 Geo::HelmertTransform(3pm)