How does time-tagging support multi-sensor fusion?

• A. By encoding timestamps in hexadecimal
• B. By assigning precise time stamps to each measurement; essential for correct synchronization and accurate fusion; mis-tagging leads to bias and drift
• C. By aligning hardware clocks to the fastest sensor
• D. By removing timestamps after processing

Answer: (B)

Time-tagging provides a common temporal reference for measurements from all sensors. When sensors run at different rates or have varying delays, knowing exactly when each reading was captured lets the fusion algorithm align data to a shared timeline. With precise time stamps, you can interpolate or propagate states to a common time step and compensate for motion between measurements, ensuring each measurement is incorporated at the correct moment. If timestamps are inaccurate or inconsistent, measurements are treated as if they come from the same instant, which introduces bias in the estimated position, velocity, or orientation and can cause drift over time. Encoding timestamps in hex, or trying to align hardware clocks to the fastest sensor, doesn’t address the fundamental need for a unified time reference. Removing timestamps eliminates the ability to synchronize data at all, making accurate fusion impossible.