Network transformation from local geodetic system (Roma 40) to WGS 84, foran international map of geocentric ellipsoid

General algorithms are given to resolve the "GPS FIX", using vectorial proc edures to transform coordinates from a local geodetic system to the WGS 84 system, with geodetic accuracy. The theory is based on the "invariance", in different geodetic systems, of the spatial distance or slope distance, that GPS receivers give with centim etric precision. The following method employs rectangular ellipsoidic coord inates (X,Y,Z) and their respective variations (Delta X,Delta Y and Delta Z ).