Wind velocity measurement with wide angle divided mirror Michelson wind imaging interferometer
SHAOJUN LU1,2,
WILLIAM E. WARD3,*
,
JEFFERY A. LANGILLE3,
SAMUEL KAARE KRISTOFFERSEN3,
CHUNMIN ZHANG1,*
Affiliation
- School of Science, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China
- School of Optical-electronic Engineering, Xi’an Technological University, Xi’an 710032, Shaanxi, China
- Physics, University of New Brunswick, 8 Bailey Drive, Fredericton, New Brunswick E3B 5A3, Canada
Abstract
Detection of atmospheric winds is needed in many fields in order to support our understanding of the atmosphere. One application of considerable interest is the monitoring of the dynamics of the thermosphere and upper mesosphere. The Michelson interferometer is an instrument capable of measuring wind velocity by detecting the Doppler shift of airglow emission lines. With the aim to get the Doppler shift needed to calculate the wind velocity, researchers have developed the four-phase-step and divided mirror technologies. A wide angle Michelson Interferometer that combines the divided mirror and phase stepping is described in this paper. Fringes of equal thickness are used to achieve excellent parallelism between the two mirrors of the Michelson Interferometer with using an iterative algorithm. Wind observations with this instrument were simulated in laboratory using a visible laser beam and rotating wheel, and the phase shifts for different wind velocities were obtained by observing fringes of equal inclination. Using a four-intensity algorithm, the wind velocity was obtained. Compared to the traditional systems wherein the four-intensity algorithm is used to detect wind velocity, the proposed system has the advantage of easily getting the phase interval of 90 degrees. The feasibility of the proposed method was proven by experiments in the visible channel..
Keywords
Divided mirror Michelson Interferometer, Wind measurement, Four-intensity algorithm.
Citation
SHAOJUN LU, WILLIAM E. WARD, JEFFERY A. LANGILLE, SAMUEL KAARE KRISTOFFERSEN, CHUNMIN ZHANG, Wind velocity measurement with wide angle divided mirror Michelson wind imaging interferometer, Optoelectronics and Advanced Materials - Rapid Communications, 11, 9-10, September-October 2017, pp.544-550 (2017).
Submitted at: April 9, 2017
Accepted at: Oct. 10, 2017