Title
Absolute Distance Measurement Using Frequency-Scanning Interferometry Based on Hilbert Phase Subdivision.
Abstract
In order to eliminate the influence of laser frequency nonlinearity, the frequency-scanning interferometry (FSI) often uses the beat signal of an auxiliary interferometer as the external clock. The time points at every amplitude peaks and bottoms of the auxiliary beat signal are selected as the sampling time points for the main interferometer signal. To satisfy the Nyquist sampling requirement, the optical path difference (OPD) of the delay fiber in auxiliary interferometer should be at least twice longer than the measurement distance. In this paper, we proposed a method to shorten the length of delay fiber. The Hilbert transform was used to extract the phase of the auxiliary interference signal and calculate the time points corresponding to subdivided phase intervals. Then, the main interference signal was resampled at these moments, and the fast Fourier transform was performed on the resampled signal. The experimental results showed that the target at the distance of about 5 m was measured when the OPD of the auxiliary interferometer was about 4.5 m. The standard deviation of the distance measurement results could reach 4.64 mu m.
Year
DOI
Venue
2019
10.3390/s19235132
SENSORS
Keywords
DocType
Volume
frequency-scanning interferometry,distance measurement,Hilbert phase subdivision
Journal
19
Issue
ISSN
Citations 
23.0
1424-8220
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Shuo Jiang100.34
Bo Liu2510.33
Huachuang Wang300.34
Bin Zhao401.01