This paper compares in-situ and path-averaged measurements of the electro-optical transmission, with emphasis on aerosol effects. The in-situ sensors consisted of optical particle counters (OPC), the path-averaged data was provided by a 7-wavelength transmissometer (MSRT) and scintillometers (BLS). Data were collected at two sites: a homogeneous test site in Northern Germany, and over the inhomogeneous False Bay near Cape Town, South Africa. A retrieval algorithm was developed to infer characteristics of the aerosol size distribution (Junge approximation) from the MSRT data. A comparison of the various sensors suggests that the optical particle counters are over optimistic in their estimate of the transmission. For the homogeneous test site, in-situ and path-averaged sensors yield similar results. For the inhomogeneous test site, sensors may react differently or temporally separated to meteorological events such as a change in wind speed and/or direction.

Date Published: 7 September 2017
PDF: 11 pages
Proc. SPIE 10408, Laser Communication and Propagation through the Atmosphere and Oceans VI, 104080V (7 September 2017); doi: 10.1117/12.2275861

Published in SPIE Proceedings Vol. 10408:
Laser Communication and Propagation through the Atmosphere and Oceans VI
Jeremy P. Bos; Alexander M. J. van Eijk; Stephen M. Hammel, Editor(s)