Module: SmoWgs84ToBng::Constants
- Included in:
- BngToWgs84, Wgs84ToBng
- Defined in:
- lib/smo_wgs84_to_bng/constants.rb
Constant Summary collapse
- WGS84_A =
WGS84 ellipsoid (GRS80, used by GPS)
6378137.000- WGS84_B =
6356752.3142- WGS84_E2 =
1 - (WGS84_B**2 / WGS84_A**2)
- AIRY_A =
Airy 1830 ellipsoid (used by OSGB36)
6377563.396- AIRY_B =
6356256.909- AIRY_E2 =
1 - (AIRY_B**2 / AIRY_A**2)
- TX =
Helmert transformation parameters: WGS84 -> OSGB36 Translation in metres, rotations in radians, scale in ppm
-446.448
- TY =
125.157- TZ =
-542.060
- RX =
(-0.1502 / 3600) * Math::PI / 180
- RY =
(-0.2470 / 3600) * Math::PI / 180
- RZ =
(-0.8421 / 3600) * Math::PI / 180
- S =
20.4894 / 1_000_000
- NG_F0 =
National Grid Transverse Mercator projection parameters
0.9996012717- NG_LAT0 =
49.0 * Math::PI / 180
- NG_LON0 =
-2.0 * Math::PI / 180
- NG_E0 =
400_000.0- NG_N0 =
-100_000.0