Definition of WGS 84.(LETTERS TO THE EDITOR)(Letter to the Editor)

Since January 1994, the World Geodetic System (WGS) 1984, the coordinate system used in GPS, has been wrongly defined thrice. Instead of using the most accurate ITRFyy(nn.0), it has been defined to "different" reference frames. Due to "double-dip" modeling of temporal effects, the ITRFs have also been "moved."

The latest least-square solution of the WGS 84 (G1150) to establish the positions of the GPS tracking stations is statistically incorrect. If this adjustment is included by a graduate student in research or thesis, he/she will only get a "D."

Standing