US Patent 11349559 Accurately determining a round trip time to a satellite

According to one or more of the embodiments herein, systems and techniques are provided for accurately determining a round trip time (RTT) to a satellite. In particular, a method according to one embodiment herein may comprise: receiving, at a device, a reference signal with a stable phase; measuring, by the device, a phase delta over time between the reference signal and an internal signal of an internal oscillator of the device; transmitting, by the device at a transmission time, a ranging signal toward a particular satellite; receiving, by the device at a reception time, a return of the ranging signal from the particular satellite; and determining, by the device, a round trip time (RTT) of the ranging signal that accounts for a phase drift of the internal oscillator between the transmission time and the reception time according to the measured phase delta over time.