An Optical Scintillometer for Simultaneous Measurements of Atmospheric C²_n and Winds

Abstract

Laser scintillations produced due to the inhomogeneities present in the atmosphere can be used for measuring refractive index structure parameter (C²_n) as well as wind velocity. The present paper deals with the description of an optical scintillometer developed at the Indian Institute of Tropical Meteorology (IITM), Pune, India for simultaneous measurements of path-averaged C²_n and crosswinds. Different evaluation techniques and their relative merits for wind estimation from optical scintillometer observations are discussed. The results show good agreement between the scintillometer evaluated winds and the winds measured simultaneously by using propeller anemometer at the same location. In addition, this paper explains the effect of C²_n and wind fluctuations along the pathlength on the derived wind information from scintillometer observations.

Indexing terms:

• Laser scintillations
• Atmospheric turbulence
• Crosswinds