CSCS Models

Several countries have produced tables of conversion factors to convert between GPS measured coordinates given in WGS84 and the corresponding local mapping coordinates, taking the distortions of the mapping system into account. Using these tables it is possible to convert into the local grid system without having to calculate your own transformation parameters. A Country Specific Coordinate System Model (CSCS Model) is an addition to an already defined coordinate system, which interpolates corrections in a grid file and applies the interpolated corrections. The extra step of applying these corrections can be made at different points in the coordinate conversion process. Therefore, different methods of CSCS Models are supported.

To import a CSCS Model:

To import a CSCS Model:

1.	In the Coordinate System Manager, select the CSCS Models tab and then Import from the ribbon bar.
2.	Browse for the *.csc file to be imported and open it.

Coordinate System Manager

CSCS Models

Import

Create a new CSCS Model:

Create a new CSCS Model:

1.	In the Coordinate System Manager, select the CSCS Models tab and then New from the ribbon bar.
2.	In the Properties window, give the geoid model unique Name.
3.	Select the option to browse for and select a CSCS Model (*.csc).
4.	Select Create to create the new CSCS Model or Cancel to exit the function.

Coordinate System Manager

CSCS Models

New

Create

Cancel

See also:

See also:

Coordinate System Manager

Conversion Methods

Conversion Methods

Grid conversion method (grid shifts):

Grid conversion method (grid shifts):

The grid file is usually based on local grid coordinates and can only be applied to coordinate systems for which a projection is defined.

1.	Step: Applying the specified transformation, map projection and ellipsoid to get preliminary grid coordinates.
2.	Step: Interpolation of a shift in Easting and Northing in the grid file of the CSCS Model to get the final local Eastings and Northings.

Cartesian conversion method (cartesian shifts):

Cartesian conversion method (cartesian shifts):

The grid file can be based on WGS84 geodetic or local geodetic coordinates and can only be applied to coordinate systems for which either a classic 3D transformation is defined or for which the transformation is none.

1.	Step: Applying the specified transformation.
2.	Step: Interpolation of a 3D shift in the grid file of the CSCS Model resulting in local cartesian coordinates.
3.	Step: Applying the specified local ellipsoid and map projection to get the final local Eastings and Northings.

Geodetic conversion method (geodetic shifts):

Geodetic conversion method (geodetic shifts):

The grid file can be based on WGS84 geodetic or local geodetic coordinates and can only be applied to coordinate systems for which the transformation is none.

1.	Step: Interpolation of a shift in geodetic latitude and longitude in the grid file of the CSCS Model resulting in final local geodetic coordinates.
2.	Step: Applying the map projection to get the final local Eastings and Northings.

Ellipsoidal conversion method (ellipsoidal shifts):

Ellipsoidal conversion method (ellipsoidal shifts):

The grid file can be based on WGS84 geodetic or local geodetic coordinates and can only be applied to coordinate systems for which an ellipsoid is defined.

1.	Step: Applying the specified transformation and the ellipsoid to get preliminary local geodetic coordinates.
2.	Step: Interpolation of a shift in geodetic latitude and longitude in the grid file of the CSCS Model resulting in final local geodetic coordinates.
3.	Step: Applying the map projection to get the final local Eastings and Northings.

CSCS Model Properties:

CSCS Model Properties:

The Properties window is filled dynamically depending on the selected CSCS Model. It shows you the Path to the imported *.csc file, the Kind of conversion method it uses, its Geodetic Datum Kind (either WGS84 or Local) and its Coordinate Type (either Grid or Geodetic) as well as the Extents and Spacing of the model.

The Interpolation Type can be either Bi-linear, Bi-quadratic or Spline and is predefined by the imported grid file, too.

The Name of a CSCS Model can always be modified even if it is in use with a coordinate system.

To be able to delete a CSCS model it must not be in use with any coordinate system.