Improvement of the Asia-Pacific TWSTFT network performance utilizing DPN results

Two-way satellite time and frequency transfer is a precise time transfer method and has being used to generate the TAI since 1999. Nowadays, TWSTFT links have formed a worldwide network and the utilization of the highly redundant TWSTFT data become an important topic. In our pervious study, a feasible method has been proposed, with full time transfer network data, to improve the results of TWSTFT network. Besides, NICT has recently developed the software-defined radio based two-way time transfer modems using the dual pseudo random noise (DPN) signal. The first DPN two-way time transfer experiments, using these modems, were performed between NICT(Japan) and TL(Taiwan) from March to December 2010 and its ability in improving the time transfer precision was approved on the Japan-Taiwan baseline. In compare with the conventional NICT-TL TWSTFT link, the DPN time transfer results have higher precision and less diurnals. Since the DPN results show better performance than the conventional TWSTFT time transfer, we would adopt the DPN results for the NICT-TL link, and solve the TWSTFT+DPN network solution by using our proposed method. The numerical results about how the DPN data can benefit the performance of TWSTFT network will be illustrated in the paper.