SEVENPAR geosoftware calculates exact transformation parameters for the spatial Helmert Seven Parameter Transformation according to Bursa-Wolf and for the Molodensky Three Parameter Transformation on the basis of identical points in different Reference Systems. The applied identical points are intensively checked for outliers and plausibility. The quality of the determined parameters is checked by cross-calculation and statistical methods and the result is stored in a cluster field. Bad matching identical points are determined and suggested for rectification. With the modeled Helmert Parameter Sets GIS and transformation programs can perform precise coordinate transformations between two geodetic Reference Systems.
Modeling of Helmert Parameter Sets
In many branches, custom defined areas and situations coordinates have to be transformed into different Coordinate Reference Systems (CRS). The geodetic software SEVENPAR is the tool of choice to calculate Helmert Parameter Sets to perform coordinate transformations between that CRS. This requires a list with the coordinates of identical points for both CRS. SEVENPAR is a very flexible tool for calculating precise Helmert Parameter Sets for exact coordinate transformations. Additional the program calculates a Rotation Matrix, the residuals of all identical points for further use, and as quality criterias the Maximum, Average and Mean Square (RMS) Residuals. After modeling a Helmert Parameter Set, its quality is checked by cross-calculation and the result is written to a cluster field. Badly fitting identical points are determined and suggested for correction. The determined transformation parameters can be entered directly into suitable transformation software, e.g. link_in TRANSDATpro Coordinate Transformation, or into the calculation software of GPS receivers to do exact Coordinate Transformations.
Modeling of Parameter-Sets for the Spatial Helmert and Molodensky Transformation with seven or three Parameters
The seven respectively three exact transformation parameters are computed with the aid of upto one million identical points. Those are points with known coordinates in two different Reference Systems (geodetic datum). Suitable are Cartesian Coordinates and also Geographical Coordinates, Gauss Kruger coordinates and UTM Coordinates with or without ellipsoidal height using the earth ellipsoid dimensions. The necessary ellipsoid half-axes and flattenings are available in the program for the selection from lists.
The coordinates of the identical points are tested intensively on outliers and deviations by different statistic procedures. The quality of the computed parameters is documented by a residual matrix and by the computation of the middle, maximum and root mean square (RMS) deviations. In addition, the quality of a Helmert Parameter Set is checked by cross-calculation.
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".
The program has a user-selectable multi language interface and comes with extensive online help. The program can be run on most common networks and it is possible to use Terminal Services on WINDOWS Servers. In case of a network installation the clients are installed automatically by the program.
