Underwater dynamic distance measurement using a cross-sampling dual-comb

Abstract

Underwater dynamic positioning plays an important role in promoting the development of marine science and technology. We experimentally demonstrate a method to perform the underwater dynamic measurement based on the cross-sampling dual-comb. The scheme aims at achieving rapid measurements for the dynamic object, and obtaining the motion state to map the dynamic position in real time. From the interferometric cues, the cross-sampling gives an intriguing way to break the constraint of periodic ambiguity. The measuring rate is doubled in a set of interferograms. The experimental results demonstrate the method has good applicability to the underwater environment. Compared to the reference values, the difference in the dynamic distance is below 71μm at the range of 5 m, corresponding to the velocity deviation of 142 μm/s in our system.