A simultaneous calibration of the IEN/PTB time link by GPS CV and TWSTFT portable equipment

The differential calibrations of GPS common-view time-receiving equipment have been made for over twenty years. Until recently, TWSTFT calibrations have been rare due to a lack of suitable equipment. Now, the Technical University of Graz is providing such a calibration service, and this paper describes a simultaneous differential calibration of the IEN/PTB time link by GPS CV and TWSTFT. The GPS calibration, although of higher uncertainty that the TWSTFT one, provides an independent check of TWSTFT calibration technique.