[cn2,Wg,Lin] = MZAsurfCn2(DATE,lat,lon,alt,press,temp,wind,windAlt, ...
                       param,value, ...)

Applies bulk modeling methods to estimate the ground level Cn2 value.

DATE [datetime] 
Date of observation. Can be a Matlab datetime object of a date vector. If not a datetime object, GMT is assumed. Ignored if ground level solar irradiance is given. 
lat [scalar] 
Latitude of observation point (deg). Ignored if ground level solar irradiance is given. 
lon [scalar] 
Longitude of observation point (deg). Ignored if ground level solar irradiance is given. 
alt [scalar] 
Altitude for Cn2 estimate (m AGL). 
press [scalar] 
Observed station pressure (Pa). 
temp [scalar] 
Observed temperature (K). 
wind [scalar] 
Observed wind speed (m/s). 
windAlt [scalar] 
Altitude (AGL) at which the wind speed is measured. 
param [char] 
Parameter name 
value [various] 
Parameter value Possible param/value options are: 'CloudCondition' - Observed cloud conditions in a 3x2 matrix. Column 1 holds the fractional cloud coverages at each layer, column 2 holds the cloud layer altitude in ft AGL. Defaults to no clouds. 'SolarIrradiance' - Ground level solar irradiance (W/m^2) 'MinSolarIrr' - Minimum value for ground level solar irradiance. Use to possibly override the NaN return when solar irradiance is low. May still get NaN under low wind conditions. NOTE: The model does not support Cn2 estimation under these conditions. 'Terrain' - Description of the site terrain (case insensitive) or surface [albedo, evap const, surface roughness (m)]. Defaults to [0.17,0.5,0.0014]. Possible terrain values:
  • 'open ocean', [0.06,1.0,0.001]
  • 'conifer forest', [0.11,1.0,1.1]
  • 'deciduous trees', [0.165,1.0,1.25]
  • 'green grass', [0.25,1.0,0.0014]
  • 'grass soil', [0.21,0.6,0.007]
  • 'bare soil', [0.17,0.2,0.01]
  • 'desert sand', [0.4,0.0,0.0003]
  • 'fresh asphalt', [0.04,0.0,0.00002]
  • 'worn asphalt', [0.1,0.0,0.00002]
  • 'old concrete', [0.27,0.0,0.00002]
  • 'new concrete', [0.55,0.0,0.00002]
  • 'ocean ice', [0.6,0.5,0.00001]
  • 'fresh snow', [0.06,1.0,0.002]
Return Values
Return Values 
cn2 [scalar] 
Estimate of ground level Cn2 (m^{-2/3}). 
Wg [scalar] 
Solar irradiance at the ground (W/m^2). 
Lin [scalar] 
Estimate of inner scale (m). 

  • Bendersky et al. "Modeling and measurements of near-ground atmospheric optical turbulence according to weather for Middle East environments," Proc. SPIE, vol. 5612, pp. 350-361, 2004.
  • F. V. Hansen, "Surface Roughness Lengths," ARL Technical Report, ARL-TR-61, August 1993.
  • D. H. Tofsted, "Modeling Turbulence Generation in the Atmospheric Surface and Boundary Layers," ARL Technical Report, ARL-TR-7503, October 2015.


>> [cn2,Wg,Lin] = MZAsurfCn2([2016 7 29 12 58 0],38.818,-76.867,2, ... 

1.0008e5,297.15,3.6011,10,'CloudCondition', ... 

[0 0; 0.75 1000; 0.75 1400],'Terrain','green grass') 

  • Cn2, ground level solar irradiance, and inner scale given time,
location, met data, cloud condition and terrain. 

>> [cn2,~,Lin] = MZAsurfCn2([],[],[],2,1.0008e5, ... 

297.15,3.6011,10,'SolarIrradiance',395.9468, ... 


  • Cn2 and inner scale given met data, ground level solar irradiance, and terrain albedo and evaporative constant.

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