sgo-package {sgo}

sgo: Simple Geographical Operations (with OSGB36).

Description

The sgo package aims to help with spatial or geographic analysis in Open Source R and derivatives. Its main purpose is to perform OSGB36/ETRS89 transformations using the Ordnance Survey's OSTN15 transformation model for Great Britain and the Isle of Man. It also transforms GPS ellipsoid heights to orthometric (mean sea level) heights on the relevant Ordnance Survey mapping datum, using the National Geoid Model OSGM15.

Details

Most of the functions available in this package will become much less accurate if used outside the coverage of OSTN, therefore it is advised to apply these functions on coordinates within Great Britain, the Isle of Man and any areas of sea less than a few miles off shore.

This package assumes that the Coordinate Reference Systems (CRS) ETRS89 and WGS84 are practically the same within the UK, but this shouldn't be a problem for most civilian use of GPS satellites. If a high-precision transformation between WGS84 and ETRS89 is required then it is recommended to use a different package to do the conversion.

Object constructors

• sgo_points: 2D/3D point coordinates

Transformation and Conversion functions

Functions to provide coordinate transformations:

• sgo_bng_lonlat: British National Grid (E/N) to Lon/Lat

• sgo_lonlat_bng: Lon/Lat to British National Grid (E/N)

• sgo_bng_ngr: British National Grid (E/N) to National Grid References

• sgo_ngr_bng: National Grid References to British National Grid (E/N)

• sgo_laea_etrs: ETRS89-LAEA Easting/Northing to ETRS89

• sgo_etrs_laea: ETRS89 to ETRS89-LAEA Easting/Northing

• sgo_cart_lonlat: 3D Earth Centred Earth Fixed (ECEF) Cartesian coordinates to polar coordinates

• sgo_lonlat_cart: Polar coordinates to 3D ECEF Cartesian coordinates

• sgo_wgs84_en: WGS84 Lon/Lat to Pseudo-Mercator (E/N)

• sgo_en_wgs84: Pseudo-Mercator (E/N) to WGS84 Lon/Lat

• sgo_transform: Wrapper for all the transformations above

• sgo_coordinates: Extract coordinates from a sgo_points object

Geometric measurements

• sgo_area: Calculate area from an ordered set of points

• sgo_distance: Calculate distance(s) between points

Disclaimer

The OSTN15 transformation model is used in this package, and it is licensed under the BSD Licence (http://opensource.org/licenses/bsd-license.php):
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