Abstract

Only the first-order Doppler frequency shift is considered in current laser dual-frequency interferometers; however; the second-order Doppler frequency shift should be considered when the measurement corner cube (MCC) moves at high velocity or variable velocity because it can cause considerable error. The influence of the second-order Doppler frequency shift on interferometer error is studied in this paper, and a model of the second-order Doppler error is put forward. Moreover, the model has been simulated with both high velocity and variable velocity motion. The simulated results show that the second-order Doppler error is proportional to the velocity of the MCC when it moves with uniform motion and the measured displacement is certain. When the MCC moves with variable motion, the second-order Doppler error concerns not only velocity but also acceleration. When muzzle velocity is zero the second-order Doppler error caused by an acceleration of 0.6g can be up to 2.5 nm in 0.4 s, which is not negligible in nanometric measurement. Moreover, when the muzzle velocity is nonzero, the accelerated motion may result in a greater error and decelerated motion may result in a smaller error.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.