searoughness

Surface height standard deviation for sea

Syntax

hgtsd = searoughness(scale)

hgtsd = searoughness(scale,'ScaleType',scaletype)

[hgtsd,beta0,windvelocity] = searoughness(___)

Description

hgtsd = searoughness(scale) returns the standard deviation of the surface height, hgtsd, for the specified sea state number as a scalar in meters.

hgtsd = searoughness(scale,'ScaleType',scaletype) specifies the scale type.

[hgtsd,beta0,windvelocity] = searoughness(___) returns additional outputs:

• beta0 — Slope of the sea type in degrees. beta0 is 1.4 times the root mean square (RMS) surface slope. The surface σ⁰ value for sea clutter reflectivity is computed based on the NRL Sea Clutter Model by Gregers-Hansen and Mittal

• windvelocity — Wind velocity in meters per second

Examples

Sea Roughness of Sea State

Obtain the surface height standard deviation in meters assuming a sea state of 2.

hgtsd = searoughness(2)

hgtsd = 0.1000

Input Arguments

scale — Sea state or wind scale

nonnegative integer

If you set scaletype to 'SeaState', scale is the sea state, specified as a nonnegative scalar between [0,8].

If you set scaletype to 'WindScale', scale is the wind scale, specified as a positive scalar between [1,9].

Example: seastate = 3

Dependency

Acceptable input values depend on the value of scaletype.

scaletype — Scale type

'SeaState' (default) | 'WindScale'

Scale type, specified as either:

• 'SeaState' — The function uses the Sea State model. When you specify this option, the scale input scale must be a nonnegative scalar between [0,8].

• 'WindScale' — The function uses the Beaufort Wind Scale model. When you specify this option, the scale input scale must be a positive scalars between [1,9].

Example: scaleType = 'WindScale'

Output Arguments

hgtsd — Standard deviation of surface height

scalar

Standard deviation of the surface height, returned as a scalar in meters.

beta0 — Slope of the sea type

scalar

Slope of the sea type β₀, in degrees, returned as a scalar.

windvelocity — Wind velocity

scalar

Wind velocity, returned as a scalar in meters per second.

References

[1] Barton, David K. Radar Equations for Modern Radar. Norwood, MA: Artech House, 2013.

Extended Capabilities

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