Research on High Precision Distance Measurement of Femtosecond Laser Based on Discrete Kalman Filter

The development of dual femtosecond laser absolute distance measurement technology, based on the time-of-flight method, presents a novel approach for applications requiring extensive range, precision, resolution, and update rate. However, the introduction of Gaussian white noise during the measurement process may lead to a reduction in distance measurement accuracy. This study proposes a method employing discrete Kalman filtering technology to enhance the precision of dual femtosecond laser absolute ranging by obtaining real-time estimation values of velocity information for dynamic targets. When the target is in motion, the Kalman filtering technique can concurrently ascertain the estimated velocity information of the moving target. The standard deviation of the estimated velocity for a uniformly moving target in a stable state is approximately 4 μ m s^-1. Additionally, when the target undergoes sinusoidal vibration, the Kalman filtering technique effectively tracks the measurement results and significantly enhances measurement accuracy.