Fiber-based time transfer system for ngVLA system

For fiber-based time transfer systems [1, 2, 3], the transmission delay can be compensated by roundtrip delay measurement. For highly accurate transmission delay compensation, the delays in the forward and backward paths of the fiber must be identical. In this method, we should consider the chromatic dispersion effect. We’ve developed a fiber-based time transfer system with the same optical frequency on both paths. This time transfer system is highly compatible with the frequency transfer system we have already developed, and can share a single fiber.