Analysis of one-way laser ranging data to LRO, time transfer and clock characterization

We characterized the LRO clock with fits throughout the mission time and estimated the rate to 6.9 × 10−8, the aging to 1.6 × 10−12/day and the change of aging to 2.3 × 10−14 /day2over all mission phases. The fits also provide referencing of onboard time to the TDB time scale at a precision of 166 ns over two and 256 ns over all mission phases, representing ground to space time transfer. Furthermore we measure ground station clock differences from the fits as well as from simultaneous passes which we use for ground to ground time transfer from common view observations. We observed relative offsets ranging from 33 to 560 ns and relative rates ranging from 2 × 10−13 to 6 × 10−12 between the ground station clocks during selected mission phases. We study the results from the different methods and discuss their applicability for time transfer.