Vertical coordinate systems are used as reference system for elevation data that is used in geographic and projected systems. Note that vertical coordinate systems are not by itself a reference system for any spatial system they are just used by geographic and projected coordinate systems.

The Application Server allows the definition of any number of vertical coordinate systems. Fore convenience some commonly used vertical coordinate systems are already predefined with every installation of the Application Server. Some of these predefined systems may be protected and cannot be modified or deleted by the user.

See table 1 for a summary of settings you can define for a vertical coordinate system.

Table 1: Settings for a vertical coordinate system

Transformation of vertical coordinate systems

The Application Server provides only limited support for transformations of spatial data between different vertical coordinate systems, i.e. it will only transform using a constant shift from and optionally a unit conversion.

For transformation of vertical coordinate systems Redbex assumes that the Conversion constant of all vertical coordinate system defined is converting the elevation data to a common basic vertical coordinate system (that common vertical coordinate system can be virtual - i.e. it does not have to be created in Redbex).

Converting a value given in one coordinate system (VCS!)to another vertical coordinate system is done with following formula:

(value * VCS1.LinearUnitConversionFactor + VCS1.ConversionConstant -   VCS2.ConversionConstant) / VCS2.LinearUnitConversionFactor

Calculations on distance and area

Calculations done on geographic or projected geometries do not use elevation data (if not stated otherwise). E.g. the distance between two points is calculated as if the two points would be at elevation zero.