Turbulence magnitude of West Africa: a virtual measuring campaign

Military operations in arid regions of the world are becoming more and more regular. The atmospheric conditions in these regions impose severe restrictions on the performance of optical systems. In contrast to regions, where many airports are located and therefore the monitoring network of ground stations is very dense, only few ground measurements are available for arid regions. To a certain extent, measurements can be collected and generalized with large-scale measurement campaigns, but they are very cost-intensive and partly not achievable due to the political situation. Another possibility to close this gap of data is provided by satellite measurements. For various measurement parameters such as humidity, wind, solar radiation and aerosols, this works quite well with some limitations. For this reason, models are a good complement to fill the lack of data in these regions. The study is concerned with identifying the turbulence in Western Sahara. The models used WRF (Weather Research and Forecasting Model) and ICON (Icosahedral Nonhydrostatic Model) have been sufficiently tested in different regions of the world. As there are no turbulence measurements in the Sahara, this is the first test to estimate the magnitude of the turbulence in order to discuss the need for an extensive measurement campaign. The models can be validated with previous trials of IOSB such as White Sands Missile Range (WSMR) in the USA, (New Mexico).

[1]  T. Chiba,et al.  Spot dancing of the laser beam propagated through the turbulent atmosphere. , 1971, Applied optics.

[2]  S. Businger,et al.  Another Look at the Refractive Index Structure Function , 2013 .

[3]  Edgar L. Andreas,et al.  Estimating Cn 2 over snow and sea ice from meteorological data , 1988 .

[4]  Shuyan Xu,et al.  Hopes and concerns for astronomy of satellite constellations , 2020 .

[5]  G. Parry Measurement of Atmospheric Turbulence Induced Intensity Fluctuations in a Laser Beam , 1981 .

[6]  Detlev Sprung,et al.  Optical turbulence in the coastal area over False Bay, South Africa: comparison of measurements and modeling results , 2018, Remote Sensing.

[7]  V. I. Tatarskii The effects of the turbulent atmosphere on wave propagation , 1971 .

[8]  D. Aminou MSG's SEVIRI instrument , 2002 .

[9]  Emilio Cuevas,et al.  USE OF MSG / SEVIRI IN THE WMO SAND AND DUST STORM WARNING ADVISORY AND ASSESSMENT SYSTEM ( SDS WAS ) FOR EUROPE , NORTH AFRICA AND MIDDLE EAST , 2008 .

[10]  Stuart A. Collins,et al.  Behavior of the Refractive-Index-Structure Parameter near the Ground* , 1971 .

[11]  Helen Brindley,et al.  Evaluation of MSG-SEVIRI mineral dust retrieval products over North Africa and the Middle East , 2013 .

[12]  Itamar M. Lensky,et al.  Clouds-Aerosols-Precipitation Satellite Analysis Tool (CAPSAT) , 2008 .

[13]  Detlev Sprung,et al.  Global simulations of Cn2 using the weather research and forecast model WRF and comparison to experimental results , 2019, Optical Engineering + Applications.

[14]  A. Ishimaru,et al.  The beam wave case and remote sensing , 1978 .

[15]  Erik Sucher,et al.  The FESTER field trial , 2016, Optical Engineering + Applications.

[16]  R. Stull An Introduction to Boundary Layer Meteorology , 1988 .

[17]  David L. Fried,et al.  Measurements of Laser-Beam Scintillation in the Atmosphere: Errata , 1967 .

[18]  James R. Lesh,et al.  Overview of the Ground-to-Orbit Lasercom Demonstration (GOLD) , 1997, Photonics West.