LEEDRWxCube

MATLAB

ModelData = LEEDRWxCube(h,modelName,[lambda],x,G,[DTEDdir], ...
                  [lutLocation],[lutDateTime])
ModelData = LEEDRWxCube(h,modelName,[lambda],lats,lons, ...
                  [DTEDdir],[lutLocation],[lutDateTime])

Description

Generates model data at specified altitudes (AGL), h, based on precomputed LEEDR Wx Cube data generated using the buildLEEDRWxCube function. To convert between MSL (used by SHaRE and ATMTools) and AGL, use TerrainAtm (requires DTED data from http://earthexplorer.usgs.gov/ - see bilLoad). If the weather cube was generated using buildLEEDRWxCube, there is an option to also generate the terrain elevation data for the cube (provided the DTED data is available). If DTEDdir is true or if DTEDdir specifies a directory with the necessary DTED data, terrain elevation data will be computed if it doesn't already exist and elevation.h5 file will be saved to the lutLocation directory. If the elevation.h5 file exists in the lutLocation directory, it will be used to convert MSL to AGL within the function. To force AGL computations, set the input DTEDdir to false.

Parameters

Parameters	Description
h [vector]	Altitude above ground level along the path (m). LEEDR weather cube data is all AGL. To convert from MSL to AGL use TerrainAtm (see example below).
ModelName [string]	Desired LEEDR model. Can be any one of the following (case insensitive): Cn2 - 'C' or 'Turb'; Abs - 'A' or 'Absorption'; Scat - 'S' or 'Scattering'; Ext - 'E' or 'Extinction'; Temp - 'T' or 'Temperature'; Wind - 'W', 'NaturalWind', or 'WindSpeed'; WindHeading - 'WH' or 'WindDir'; Press - 'P' or 'Pressure'; RH - 'R' or 'RelativeHumidity'; Albedo - 'Alb' or 'Albedo'; Density - 'D', 'AirDensity', or 'Density' GroundAlt - 'G', 'GA', or 'GroundAlt'
lambda [scalar]	(Optional) Desired wavelength for computation of absorption, scattering, and extinction (m). This input is only required for model types 'A', 'S', and 'E', can be omitted otherwise. Screen positions either as
x [scalar/vector]	Number of screens or norm screen locations
G [struct]	Geometry structure as from GeomStruct OR
lats [vector]	Latitudes of screen locations (deg)
lons [vector]	Longitudes of screen locations (deg)
DTEDdir [bool/char]	(Optional) Directory holding the downloaded DTED data - data can be downloaded from http://earthexplorer.usgs.gov/. Set to false to prevent generation and/or use of elevation data. If true, uses elevation data to convert from MSL to AGL altitudes and will generate elevation data if not there and DTED data is in the default DTED directory - (EngagementToolsPath(-1)/DTED). Defaults to true.
lutLocation [string]	(Optional) Location identifier for the weather cube. Defaults to last used value.
lutDateTime [string]	(Optional) Date/time/cycle identifier for weather cube in the format of YYYYMMDDHHHHCCC such as '201501010000006' for 1 Jan 2015, 00:00, 6 hour forecast. Defaults to the last used value.

Return Values

Return Values	Description
ModelData [vector]	Model values at specified altitudes.

Examples

>> G = GeomStruct('LLA',[38.9 -76.8 50],[39.02 -76.96 193]);

>> Atm = AtmStruct(G,10, ...

'Cn2','LEEDRWxCube','C','x','G',false,'NCR','201501010000006', ...

'Ext','LEEDRWxCube','E',1.06e-6,'x','G',false,'NCR','201501010000006')

Generate an Atm structure using LEEDR data for turbulence and extinction (should use 'x' and 'G' so if geometry changes, the screen positions will also get updated). This assumes ground level of 0 meters and no terrain effects.

>> LLA = ecf2LLA(ScreenECF(10,G));

>> Cn2 = LEEDRWxCube(LLA(:,3),'C',LLA(:,1),LLA(:,2),'C:MyDTEDdir','NCR','201501010000006')

Uses elevation.h5 data, if present, OR generates from DTED data in C:MyDTEDdir if all necessary data has been downloaded. If elevation.h5 does not exists and DTED data is not available, assumes 0 ground altitude.

>> ext = LEEDRWxCube(LLA(:,3),'E',1.06e-6,LLA(:,1),LLA(:,2), ...

true,'NCR','201501010000006')

Uses elevation.h5 data, if present, OR attempts to generate from default DTED directory

>> ext = TerrainAtm(LLA(:,3),grndAlt,'LEEDRWxCube','E',1.06e-6, ...

LLA(:,1),LLA(:,2),true,'NCR','201501010000006')

Compute extinction for fixed ground level grndAlt. TerrainAtm will pass AGL altitudes to LEEDRWxCube and will update the call to LEEDRWxCube to force AGL calculations.

>> Atm = AtmStruct(G,100, ...

'Cn2','TerrainAtm','LEEDRWxCube','C','x','G',true,'NCR','201501010000006', ...

'Ext','TerrainAtm','LEEDRWxCube','E',1.06e-6,'x','G',true,'NCR','201501010000006')

Atm structure with turbulence and extinction using TerrainAtm with elevation data to adjust altitude.