GeoDLL - Function Groups
At present 2 to 7 cm per year
GeoDLL supports the development of geodetic software by providing geodetic functions, which are put together into function groups for specific tasks. To calculate Helmert and Molodensky parameter sets in own developments a license for the function group "Transformation Parameter" can be purchased.
This function group provides functions for the calculation of highly exact transformation parameters for the Spatial Helmert and Molodensky Transformation, which make possible precise Coordinate Transformations from one Reference System into another. The determined transformation parameters can be entered directly into suitable transformation software, e.g. TRANSDATpro Coordinate Transformations, or into the calculation software of GPS receivers to do exact Coordinate Transformations.
The seven respectively three exact transformation parameters are computed with the aid of up to 30.000 identical points. Those are points with known coordinates in two different Reference Systems. Identical measuring points of higher order can be inquired or referred by the official measurement surveys.
The coordinates of the identical points can be tested on outliers and residuals by different statistic functions. The quality of the computed parameters can be documented by a residual matrix and by the computation of the middle, maximum and root mean square (RMS) deviations.
The seven parameters of the Spatial Helmert Transformation are calculated in the three standards "Coordinate Frame Rotation", "Position Vector Transformation" and "European Standard ISO 19111". The three parameters for Molodenky parameter sets are calculated using the "Standard Molodensky Transformation".
Detailed descriptions of all geodetic functions of this function group you find here in the online manual!