Geographic offset by interpolation of gridded data

[robertogiachetta]

Geographic Offset by Interpolation of Gridded Data is a collection of coordinate operations applied over a predefined spatial grided data set with latitude and longitude offsets. This include the following grid: NADCON which is used by the US National Geodetic Survey for transformation between US systems; NTv2 which originated in the national mapping agency of Canada and was subsequently adopted in Australia, New Zealand and then several other countries; and OSTN used in Great Britain.

See: OGP Publication 373-7-2 – Geomatics Guidance Note number 7, part 2, page 145.

Add coordinate operations implementing these interpolations as descendants of CoordinateTransformation<GeoCoordinate> in the Core.Reference/Collections.Formula namespace in the Transformations folder. The interpolation should be defined in a base class for all offsets (i.e. GeographicOffsetByInterpolation), and subclasses (e.g. NTv2GeographicOffsetByInterpolation) should load the different grid files. Grid files can be added to the Core.Reference/Resources folder as built-in resources.