Important Parameters Used in Geodetic Transformations

Modern geodetic space techniques, such as Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging, (SLR), and Global Positioning Systems (GPS), can accurately determine the seven parameters of similarity transformations between different terrestrial (i.e., earth-centered and earth-fixed) frames. For the benefit of the surveying engineers utilizing portable satellite receivers (e.g., Doppler, GPS), this article compiles (adopting conventional notations) recently estimated values of the shifts, rotations, and scale relating the most frequently used (e.g., WGS-72, WGS-84) reference frames. The sign of these parameters are consistant with the standard matrix form of the similarity transformation equation, which for completeness is also included in the appendix. This should be kept in mind when they are compared to other tabulated values recently published in the geodetic literature.