lv95 0.0.1

A dart package that provides conversions between Swiss LV95 (CH1903+) coordinates and WGS84 coordinates.

LV95 / WGS84 conversion

This package provides conversions between Swiss LV95 (CH1903+) coordinates and WGS84 coordinates.

Usage

import 'package:lv95/lv95.dart';

final wgs84 = LatLng(46.93371248052634, 7.120573812162601);
final xy = LV95.fromWGS84(wgs84);
print(xy); // Prints XY(x:1198118.3615880755, y:2575779.6599590005)

final wgs84_2 = LV95.toWGS(xy);
print(wgs84_2); // Prints LatLng(46.93371394740376, 7.120579242285814)

The default implementation uses a fast approximation algorithm. By specifying precise:true you can request the usage of a very precise but slower algorithm. When using precise calculations you can further increase the accuracy of the conversion by indicating the height above sea level of the specified location, in case this information can be determined by your GNSS receiver or is otherwise known.

import 'package:lv95/lv95.dart';

final wgs84 = LatLng(46.93371248052634, 7.120573812162601);
final xy = LV95.fromWGS84(wgs84, precise: true, height: 431.3);
print(xy); // Prints XY(x:1198118.3469151012, y:2575779.6827807147)

Now the result exactly matches the one given by the official online converison tool by swisstopo.

Reference

The calculations used by the library are based on the official formulas given by the Swiss Federal Office of Topography (swisstopo):

Formulas and constants for the calculation of the Swiss conformal cylindrical projection and for the transformation between coordinate systems