Velocity correction of the Janus configuration laser Doppler velocimeter

The error of laser Doppler velocimeter (LDV) based on Janus configuration is analyzed as the vehicle inclines. Analysis shows that the error of the Janus configuration LDV depends on the vertical velocity to horizontal velocity ratio (VHR) only. But the measurement accuracy of the Janus configuration LDV will be not high enough to meet the requirement of vehicle self-contained navigation system, if the VHR of the vehicle is overlarge in powerful rough ground. The error of the Janus configuration LDV is corrected through an inclinometer whose precision of angle needed is only 2%. Simulation shows that the error of the Janus configuration LDV after correction can be limited below 0.1% even as the VHR reaches 0.3 and pitch angle is 15°.

► We analyzed the velocity error of the Janus configuration laser Doppler velocimeter (LDV).
► The error of the Janus configuration LDV is insensitive to the pitch angle.
► Increasing of the vertical velocity to the horizontal velocity ratio will increasing the velocity error.
► A velocity correction is carried out to improve the accuracy of the Janus configuration LDV.
► Velocity error after correction is better than 0.1% as the VHR = 0.3 and the pitch angle = 15°.