LONG DISTANCE INTERFEROMETRIC MEASUREMENTS WITH REFRACTIVE INDEX CORRECTION BASED ON SPEED OF SOUND

Milena Astrua, Marco Pisani, Massimo Zucco
Abstract:
At INRIM a novel absolute long distance interferometer has been developed for application in space missions. The interferometer has been successfully tested for long distance measurements in air. Main limitation of such measurements is the knowledge of refractive index of air which in turn is mainly affected by air temperature. A method to measure average air temperature based on the measure of the speed of sound has been developed and combined with the absolute interferometer achieving measurement uncertainties less than 1 ppm in open air up to a 78 m distances.
Keywords:
long distance interferometry, refractive index of air, temperature measurement, synthetic wavelength
Download:
IMEKO-TC14-2014-21.pdf
DOI:
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Event details
IMEKO TC:
TC14
Event name:
TC14 LMPMI Symposium 2014
Title:

11th Symposium on Laser Metrology for Precision Measurement and Inspection in Industry

Place:
Tsukuba, JAPAN
Time:
03 September 2014 - 05 September 2014