Irregular Wave

R2026b

Generate ocean surface heightmap using irregular wave spectrum models

Since R2026b

• 

Irregular Wave block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Aerospace Blockset Maritime Applications Library / Environment

Description

Add-On Required: This feature requires the Aerospace Blockset Maritime Applications Library add-on.

The Irregular Wave block generates ocean surface heightmaps using one of these irregular wave spectrum models:

• Bretschneider

• JONSWAP

• Scott

• Ochi-Hubble bimodal

• TMA spectrum

The Irregular Wave block uses Seed values to create spatially and statistically irregular wave fields that enable the simulation of realistic sea states for maritime modeling and validation. The block does not create a single, repeating wave pattern. Instead, it creates irregular waves that combine multiple regular waves with different amplitudes and phases, creating a seemingly random pattern.

Ports

Input

d — Water depth

scalar double

Water depth, specified as a scalar double in the specified units.

Dependencies

To enable this port, set Spectral form to TMA spectrum.

Data Types: double

Output

Wave heightmap — Heightmap

N-by-M

Heightmap that describes the surface of water generated using the selected wave spectrum model, returned as an N-by-M array, in the units specified in Units. The heightmap size is the same as the Grid size parameter size.

Data Types: double

Parameters

To edit block parameters interactively, use the Property Inspector. From the Simulink^® Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Main

Units — Parameter and port units

Metric (MKS) (default) | English

Parameter and port units, specified as one of these values:

Units	Surface Size	Wave Height	Wind Speed	Resolution
Metric (MKS)	meters	m	m/s	m
English	feet	ft	ft/s	ft

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	units
Values:	Metric (MKS) (default) | English

Example: set_param(gcb,"units","Metric (MKS)")

Grid size — Surface size

[100 100] (default) | 2-element row vector | finite positive integers greater than or equal to 2

Surface size of the generated water surface, specified as an 2-element row vector of finite positive integers greater than or equal to 2, where:

• N — Number of rows of the heightmap.

• M — Number of columns of the heightmap.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	gridSize
Values:	[100 100] (default) | 2-element row vector | finite positive integers greater than or equal to 2
Data Types:	double

Example: set_param(gcb,"gridSize","[100 100]")

Resolution (m) — Distance between each grid point

1 (default) | finite positive scalar

Distance between each grid point, specified as a finite positive scalar.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	resolution
Values:	1 (default) | finite positive scalar
Data Types:	double

Example: set_param(gcb,"resolution","1")

Frequency range (rad/s) — Range of frequency samples

[0.2 1.2] (default) | finite positive or zero, 2-element row vector

Range of frequency samples, specified as a finite positive or zero, 2-element row vector [umin umax], where umin must be less than umax.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	omegaRange
Values:	[0.2 1.2] (default) | finite positive or zero, 2-element row vector
Data Types:	double

Example: set_param(gcb,"omegaRange","[0.2 1.2]")

Number of frequency samples — Number of frequencies

16 (default) | finite positive scalar or 0

Number of frequencies at which the spectrum is sampled, specified as a finite positive scalar or 0.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	nOmega
Values:	16 (default) | finite positive scalar or 0
Data Types:	double

Example: set_param(gcb,"nOmega","16")

Seed — Seed value

1 (default) | finite scalar integer greater than or equal to 0

Seed value, specified as a finite scalar integer greater than or equal to 0.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	seed
Values:	1 (default) | finite scalar integer greater than or equal to 0
Data Types:	double

Example: set_param(gcb,"seed","1")

Spectrum

Spectral form — Spectral forms

Bretschneider (default) | JONSWAP | Scott | Ochi-Hubble bimodal | TMA spectrum

Spectral forms, specified as one of these values:

• Bretschneider — Model a fully developed sea.

• JONSWAP — Joint North Sea Wave Project. Model a fetch‑limited (developing) sea.

• Scott — Model for idealized conditions.

• Ochi-Hubble bimodal — Model seas with two dominant (bimodal) wave systems.

• TMA spectrum — Model waves in finite or shallow water.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	spectralForm
Values:	Bretschneider (default) | JONSWAP | Scott | Ochi-Hubble bimodal | TMA spectrum

Example: set_param(gcb,"spectralForm","Bretschneider")

Spectrum model for Bretschneider form — Bretschneider spectrum model

Single parameter Pierson-Moskowitz (default) | Two parameter Pierson-Moskowitz | ITTC | ISSC

Bretschneider spectrum model, specified as one of these values:

• Single parameter Pierson-Moskowitz — Fully developed sea using a one-parameter Pierson–Moskowitz (PM) formulation.

• Two parameter Pierson-Moskowitz — Modified PM/Bretschneider formulation defined by two sea-state parameters.

• ITTC — International Towing Tank Conference (ITTC) standard wave spectrum used in marine model testing.

• ISSC — Bretschneider spectrum, also known as modified Pierson–Moskowitz.

Dependencies

To enable this parameter, set Spectral form to Bretschneider.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	gpmSpectrumModel
Values:	Single parameter Pierson-Moskowitz (default) | Two parameter Pierson-Moskowitz | ITTC | ISSC

Example: set_param(gcb,"gpmSpectrumModel","Single parameter Pierson-Moskowitz")

Select spectrum input parameter — Model spectrum input

Significant wave height (default) | Wind speed | Peak frequency

Model spectrum input, specified as one of these values:

• Significant wave height — Average height of the highest one-third of waves in a sea state.

• Wind speed — Wind velocity referenced at a 10 meters above the sea surface.

• Peak frequency — Frequency at which the wave spectrum reaches its maximum spectral density.

The block uses this input to define the wave spectrum model.

Dependencies

To enable this parameter:

• Set Spectral form to Bretschneider or TMA spectrum.

or

• Set Spectrum model for Bretschneider form to Single parameter Pierson-Moskowitz.

• Set Select spectrum input parameter to Wind speed.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	spectralParameter
Values:	Significant wave height (default) | Wind speed | Peak frequency

Example: set_param(gcb,"spectralParameter","Significant wave height")

Significant wave height — Average height of highest one-third of waves

1 (default) | finite positive scalar or 0

Average height of highest one-third of waves, specified as a finite positive scalar or 0.

Dependencies

To enable this parameter:

• Set Spectral form to Bretschneider.

• Set Spectrum model for Bretschneider form to Single parameter Pierson-Moskowitz, Two parameter Pierson-Moskowitz, ITTC, or ISSC.

or

• Set Spectral form to Scott or Ochi-Hubble bimodal.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	waveHeight
Values:	1 (default) | finite positive scalar
Data Types:	double

Example: set_param(gcb,"waveHeight","1")

Wind speed (U10) — Wind speed

10 (default) | finite real positive scalar greater than or equal to 0

Wind speed, specified as a finite real positive scalar greater than or equal to 0.

Dependencies

To enable this parameter:

• Set Spectral form to JONSWAP or TMA spectrum.

or

• Set Spectral form to Bretschneider.

• Set Spectral model for Bretschneider form to Single parameter Pierson-Moskowitz.

• Set Select spectral input parameter to Wind speed.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	windSpeed
Values:	10 (default) | finite real positive scalar greater than or equal to 0
Data Types:	double

Example: set_param(gcb,"windSpeed","10")

Peak frequency — JONSWAP spectral peak sharpness

1 (default) | finite real positive scalar greater than or equal to 0

JONSWAP spectral peak sharpness, specified as a finite real positive scalar greater than or equal to 0.

Dependencies

To enable this parameter:

• Set Spectral form to Bretschneider.

• Set Spectrum model for Bretschneider form to Two parameter Pierson-Moskowitz or ITTC.

or

• Set Spectral form to Bretschneider.

• Set Spectrum model for Bretschneider form to Single parameter Pierson-Moskowitz.

• Set Select spectrum input parameter to Peak frequency.

or

• Set Spectral form to Scott.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	peakFrequency
Values:	1 (default) | finite real positive scalar greater than or equal to 0
Data Types:	double

Example: set_param(gcb,"peakFrequency","1")

Fetch distance (m) — Horizontal distance

100 (default) | finite positive scalar

Horizontal distance over which the wind blows in a consistent direction and speed across a body of water, finite positive scalar.

Dependencies

To enable this parameter, set Spectral form to JONSWAP or TMA spectrum.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	fetch
Values:	100 (default) | finite positive scalar
Data Types:	double

Example: set_param(gcb,"fetch","100")

Peak enhancement factor — Peak enhancement factor

3.3 (default) | finite positive scalar between 1 and 7, noninclusive

Peak enhancement factor, specified as a finite positive scalar between 1 and 7, noninclusive.

Dependencies

To enable this parameter, set Spectral form to JONSWAP or TMA spectrum.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	gamma
Values:	3.3 (default) | finite positive scalar between 1 and 7, noninclusive
Data Types:	double

Example: set_param(gcb,"gamma","3.3")

Mean frequency — Spectral mean frequency

1 (default) | finite positive scalar or 0

Spectral mean frequency, specified as a finite positive scalar or 0.

Dependencies

To enable this parameter:

• Set Spectral form to Bretschneider.

• Set Spectrum model for Bretschneider form to ISSC.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	meanFrequency
Values:	1 (default) | finite positive scalar
Data Types:	double

Example: set_param(gcb,"meanFrequency","1")

Direction

Angle units — Unit system for angular parameters

Degrees (default) | Radians

Unit system for angular parameters, specified as Degrees or Radians.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	angleUnits
Values:	Degrees (default) | Radians

Example: set_param(gcb,"angleUnits","Degrees")

Mean wave direction (deg) — Mean wave direction

0 (default) | finite positive scalar between 0 and 360, inclusive

Mean wave direction, specified as a finite positive scalar between 0 and 360, inclusive.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	meanWaveDirection
Values:	0 (default) | finite positive scalar between 0 and 360, inclusive
Data Types:	double

Example: set_param(gcb,"meanWaveDirection","0")

Enable directional spreading — Option to control multidirectional spreading function

off (default) | on

To enable the multidirectional spreading function, which defines the randomness in direction, select this parameter. Otherwise, clear this parameter.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	enableDirectionalSpreading
Values:	off (default) | on

Example: set_param(gcb,"enableDirectionalSpreading","off")

Directional spreading function — Mathematical function to distribute wave spectrum

Cosine-squared (default) | Cosine-2s

Mathematical function to distribute wave spectrum, D(ω, θ), a function of frequency and direction, specified as Cosine-squared or Cosine-2s.

Dependencies

To enable this parameter, select the Enable directional spreading parameter.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	directionalSpreadingFunction
Values:	Cosine-squared (default) | Cosine-2s

Example: set_param(gcb,"directionalSpreadingFunction","Cosine-squared")

Number of direction samples — Number of direction samples

4 (default) | finite positive scalar integer

Number of direction samples, specified as a finite positive scalar integer.

Dependencies

To enable this parameter select the Enable directional spreading parameter.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	nTheta
Values:	4 (default) | finite positive scalar integer
Data Types:	double

Example: set_param(gcb,"nTheta","4")

Spreading factor — Spreading function

1 (default) | finite positive scalar integer

Spreading function, specified as a finite positive scalar integer.

Dependencies

To enable this parameter:

• Select the Enable directional spreading parameter.

• Set the Directional spreading function to Cosine-2s.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter:	spreadingFactor
Values:	1 (default) | finite positive scalar integer
Data Types:	double

Example: set_param(gcb,"spreadingFactor","1")

Version History

Introduced in R2026b