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Horizontal Wind Model 07

Implement Horizontal Wind Model 07

  • Library:
  • Aerospace Blockset / Environment / Wind

  • Horizontal Wind Model 07 block


The Horizontal Wind Model 07 block implements the U.S. Naval Research Laboratory HWM™ routine to calculate the meridional and zonal components of the wind for a set of geographic coordinates: latitude, longitude, and altitude.


For code generation, use this block only for targets whose type is int 32 or higher.



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Geodetic latitude (μ), longitude (l), and geopotential altitude (h), specified as a three-element vector.

Latitude and longitude values are in degrees.

Altitude values are held outside the range 0 to 500 km. The altitude value is in the units selected in Units.

Data Types: double

Day of year in Universal Coordinated Time (UTC), specified as a value between 1 and 366 (for a leap year). Values are wrapped within the range 1 to 366 days.

Data Types: double

Elapsed seconds since midnight for the specified day, in UTC.

Data Types: double

Ap index for the Universal Time (UT), specified as a scalar, ranging from 0 to 400. Select the index from NOAA National Geophysical Data Center, which contains 3 hour interval geomagnetic disturbance index values. If the Ap index value is greater than zero, the software takes into account magnetic effects during model evaluation.


To enable this port, set Model to Total or Disturbance.

Data Types: double


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Wind velocity vector, returned as a 1-by-2 vector, containing the meridional and zonal wind components, in that order.

Data Types: double


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Input and output units, specified as:


Wind Speed

Wind Velocity

Metric (MKS)

Meters per second

Meters per second

English (Velocity in ft/s)

Feet per second

Feet per second

English (Velocity in kts)



Programmatic Use

Block Parameter: units
Type: character vector
Values: 'Metric (MKS)' | 'English (Velocity in ft/s)' | 'English (Velocity in kts)'
Default: 'Metric (MKS)'

Horizontal wind model type for which to calculate the wind components, specified as:

  • Disturbance

    Calculate the effect of only magnetic disturbances in the wind.

  • Quiet

    Calculate the horizontal wind model without magnetic disturbances.

  • Total

    Calculate the combined effect of the quiet and magnetic disturbances.

Programmatic Use

Block Parameter: model
Type: character vector
Values: 'Quiet' | 'Total' | 'Disturbance'
Default: 'Quiet'

Out-of-range block behavior, specified as follows.



No action. The block imposes upper and lower limits on an input signal.


Warning in the Diagnostic Viewer, model simulation continues. For Accelerator and Rapid Accelerator modes, setting the action to Warning has no effect and the model behaves as though the action is set to None.


MATLAB® returns an exception, model simulation stops. For Accelerator and Rapid Accelerator modes, setting the action to Error has no effect and the model behaves as though the action is set to None.

Programmatic Use

Block Parameter: action
Type: character vector
Values: 'None' | 'Warning' | 'Error'
Default: 'Warning'

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2014b

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Behavior changed in R2021b