Engee documentation

seaSurface

The sea surface related to the radar scenario.

Library

EngeeRadars

Description

Function seaSurface defines a sea surface object belonging to the function radarScenario.

Use the function seaSurface to specify surface dimensions, reflectivity, wind movement, reference height, and digital terrain data. Use the function height to specify the height of the surface at a point.

Syntax

Function call

  • srf = seaSurface(scenario) — creates and adds an object srf to the object scenario, created by the function radarScenario.

  • srf = seaSurface(scenario,Name=Value) — creates an object srf with properties specified by one or more arguments of the type «name-value». Unspecified properties retain their default values.

Arguments

Input arguments

# scenario — RL scenario

+ object

Details

The radar scenario created by the function radarScenario.

Input arguments «name-value»

Specify optional argument pairs as Name=Value, where Name — the name of the argument, and Value — the appropriate value. You can specify multiple pairs «name-value».

# SpectralModel — the spectrum of omnidirectional motion of the sea surface

+ the seaSpectrum object

Details

The spectrum of omnidirectional motion of the sea surface, defined as an object seaSpectrum. This object simulates the height of the surface in time.

Dependencies

To use this argument, set for the argument IsEarthCentered functions radarScenario meaning false.

# Boundary — the bounding rectangle of the surface

+ [−Inf Inf; −Inf Inf] (by default) | the matrix

Details

The boundaries of a rectangular surface, defined as a real matrix of size 2 on 2. The bounding rectangle is defined by two two-dimensional points in Cartesian or geodetic coordinates of the scenario. For the argument IsEarthCentered functions radarScenario One of the following values can be set:

  • false — the coordinates of the scenario are Cartesian. Specify the bounding rectangle as [minX, maxX, minY maxY], where minX and maxX — minimum and maximum values along the axis coordinate systems, and minX < maxX, and minY and maxY — minimum and maximum values along the axis coordinate systems, and minY < maxY.

  • true — geodetic coordinates of the scenario. Specify the bounding rectangle as [startLat, endLat, startLon endLon], where startLat and endLat — the minimum and maximum latitudes of the geodetic coordinate system, while they must be in the range [−90, 90] and startLat < endLat, and startLon and endLon — the minimum and maximum longitudes of the geodetic coordinate system, while they must be in the range [−180, 180]. If endLon < startLon, the object closes on endLon before startLon + 360°. The units of measurement are degrees.

Типы данных

Float64

# ReflectionCoefficient — value of the surface reflection coefficient

+ scalar

Details

The surface reflection coefficient for use in multipath calculations, given as a scalar from −1 before 1.

Support for complex numbers

Yes

# ReflectivityMap — index map of surface reflectivity types

+ 1 (by default) | scalar | the matrix

Details

This argument contains a grid of reflectivity type values corresponding to the vertices of the surface height data. If a relief or spectral model is present, the value ReflectivityMap it must be a matrix of the same size as the definition area of this data. Otherwise, it must be a scalar.

Типы данных

Float64

# ReferenceHeight — reference height of the surface

+ 0 (by default) | scalar

Details

The reference value of the surface height data, set as a scalar in meters. The surface heights are set relative to the reference height.

Типы данных

Float64

# WindSpeed — wind speed

+ 10 (by default) | scalar

Details

The wind speed above the sea surface, given as a non-negative scalar in m/s. The wind speed is determined at altitude 10 m from the surface of the water. The wind speed is used as a parameter for the corresponding spectral model.

Типы данных

Float64

# WindDirection — wind direction

+ 0 (by default) | scalar

Details

The wind direction above the sea surface, set as a scalar in degrees ranging from 0° up to 180°. The standard right-hand Cartesian coordinate system is used. If for an argument IsEarthCentered functions radarScenario the value is set true, the wind direction is a positive angle set counterclockwise relative to the positive axis . Otherwise, the wind direction is determined clockwise relative to the north direction. This argument is used to determine the reflectivity of the surface and as a parameter for the corresponding spectral model.

Типы данных

Float64

# Fetch — wave acceleration

+ Inf (by default) | scalar

Details

The acceleration of the wave, set as a positive scalar in meters. Wave acceleration is the distance above the sea surface at which the wind blows in one direction without obstacles. The acceleration of the wave is used as a parameter for the corresponding spectral model.

Типы данных

Float64

Output arguments

# srf — sea surface

+ object

Details

The sea surface related to the radar scenario.