A genetic approach for coordinate transformation test of GPS positioning

Transformation of coordinates usually invokes level-wise processes wherein several sets of complicated equations are calculated. Unfortunately, the accuracy may be corrupted due to the accumulation of inevitable errors between the transformation processes. This letter rephrases the transformation of coordinates from global positioning system (GPS) signals to 2-D coordinates as a regression problem that derives target coordinates from the inputs of GPS signals directly. In this letter, a genetic-based solution is proposed and implemented by the techniques of symbolic regression and genetic programming. Since coordinates for a GPS application are obtained by using simpler transformation formulas, the computational costs and inaccuracy can be reduced. The proposed method, although it does not exclude systematic errors due to the imperfection on defining the reference ellipsoid and the reliability of GPS receivers, effectively reduces statistical errors when accurate Cartesian coordinates are known from independent sources. To our best knowledge, this letter is the first attempt to use genetic-based methods in coordinate transformation for GPS positioning. From the experimental results where the target datums TWD67 and TWD97 are investigated, it seems that the proposed method can serve as a direct and feasible solution to the transformation of GPS coordinates.