Systems and methods for measuring rotation and velocity

A method for measuring rotation of a system, the method comprising:

• transmitting a signal along a path, the time of the first signal transmission defining the start of a sample period;
• receiving the signal at a receiver;
• throughout the sample period, in response to receiving the signal at the receiver, retransmitting the signal from the transmitter;
• determining the time between the first signal transmission and the reception of the final retransmitted signal when the sample period has ended;
• and
• using the time between the first signal transmission and the reception of the final retransmitted signal to determine a corresponding rotation of the system over the sample period.

A system for determining linear velocity, comprising:

• a first transmitter and a first receiver;
• a second transmitter and a second receiver;
• a first path connecting the first transmitter to the first receiver;
• a second path connecting the second transmitter to the second receiver;
• and
• a processor, wherein:
• the first transmitter is configured to transmit a signal to the first receiver, the time of the first signal transmission defining the start of a sample period;
• the second transmitter is configured to retransmit the signal to the second receiver in response to the signal being received at the first receiver throughout the sample period;
• the first transmitter is further configured to retransmit the signal to the first receiver in response to the retransmitted signal being received at the second receiver throughout the sample period;
• the first and second paths have different baseline signal travel times;
• the processor is configured to determine the time between the first signal transmission and the reception of the final retransmitted signal at the first or second receiver when the sample period has ended;
• and
• the processor is further configured to use the time between the first signal transmission and the reception of the final retransmitted signal at the first or second receiver to determine a corresponding linear velocity over the sample period.