TOF ranging method belongs to two-way ranging technology, which mainly uses the flight time of signals between two asynchronous transceivers to measure the distance between nodes. Because the TOF-based ranging method has a linear relationship with the distance in the line-of-sight environment, the result will be more accurate. We record the time interval between the sender sending the data packet and the receiver receiving the response as TTOT, and the time interval between the receiver receiving the data packet and sending the response as TTAT. Then the time TTOF of the data packet flying in one direction in the air can be calculated as TTOF=(TTOT-TTAT)/2, and then the distance between two points can be calculated according to the results of TOF and electromagnetic wave propagation speed, D=CxTTOF.
In order to achieve constant synchronization, TOF ranging method uses clock offset to solve the clock synchronization problem. Find out that Zhengzhou Li Anrui Electronic Technology uses reverse measurement method in detail, that is, remote nodes send data packets, local nodes receive data packets, and automatically respond. By averaging the average values of forward and reverse measurements, the influence on any clock offset is reduced, thus reducing the ranging error.