The goal of the proposed project is to develop a modem for Two-Way Satellite Time and Frequency Transfer (TWSTFT), based on a fully digital implementation, challenging the current state-of-art performance, and finished to allow small series industrial production and operation requirements.
The technique of TWSTFT is known for decades. The main usage nowadays is in the field of world-wide metrology of time, helping to keep UTC defined across continents. It is also an important part of the ground segments of GNSSes as well as regional navigation satellite systems.
The method is one of the only two techniques allowing to perform accurate time and frequency transfer at a global scale – the other being GNSS-based time transfer. The main advantage of TWSTFT compared to GNSS time transfer (such as GNSS+IPPP) lies in the fact, that TWSTFT  is able to precisely distinguish the uncertainties in range (such as ground station—satellite range) over uncertainties in time (clock offset). Thanks to this, TWSTFT is almost independent of external corrections (products), and shall always deliver (considerably) more precise results.
The TWSTFT modem will be built in a shape of 19”-rack-mount instrument, connected via RF connectors to a local time source, to satellite up/down-converter, and optionally to a local computer network.