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patternElevation

System object: phased.IsotropicHydrophone
Package: phased

Plot isotropic hydrophone directivity and response patterns versus elevation

Syntax

patternElevation(hydrophone,FREQ)
patternElevation(hydrophone,FREQ,AZ)
patternElevation(hydrophone,FREQ,AZ,Name,Value)
PAT = patternElevation(___)

Description

patternElevation(hydrophone,FREQ) plots the 2-D element directivity pattern versus elevation (in dBi) for the element hydrophone at zero degrees azimuth angle. The argument FREQ specifies the operating frequency.

patternElevation(hydrophone,FREQ,AZ), in addition, plots the 2-D element directivity pattern versus elevation (in dBi) at the azimuth angle specified by AZ. When AZ is a vector, multiple overlaid plots are created.

patternElevation(hydrophone,FREQ,AZ,Name,Value) plots the element pattern with additional options specified by one or more Name,Value pair arguments.

PAT = patternElevation(___) returns the element pattern. PAT is a matrix whose entries represent the pattern at corresponding sampling points specified by the 'Elevation' parameter and the AZ input argument.

Input Arguments

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Isotropic hydrophone, specified as a phased.IsotropicHydrophone System object.

Example: phased.IsotropicHydrophone

Frequency for computing directivity and pattern, specified as a positive scalar. Frequency units are in hertz.

  • For an antenna or microphone element, FREQ must lie within the range of values specified by the FrequencyRange or the FrequencyVector property of the element. Otherwise, the element produces no response and the directivity is returned as –Inf. Most elements use the FrequencyRange property except for phased.CustomAntennaElement and phased.CustomMicrophoneElement, which use the FrequencyVector property.

  • For an array of elements, FREQ must lie within the frequency range of the elements that make up the array. Otherwise, the array produces no response and the directivity is returned as –Inf.

Example: 1e8

Data Types: double

Azimuth angles for computing sensor or array directivities and patterns, specified as a 1-by-N real-valued row vector where N is the number of desired azimuth directions. Angle units are in degrees. The azimuth angle must lie between –180° and 180°.

The azimuth angle is the angle between the x-axis and the projection of the direction vector onto the xy plane. This angle is positive when measured from the x-axis toward the y-axis.

Example: [0,10,20]

Data Types: double

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Displayed pattern type, specified as the comma-separated pair consisting of 'Type' and one of

  • 'directivity' — directivity pattern measured in dBi.

  • 'efield' — field pattern of the sensor or array. For acoustic sensors, the displayed pattern is for the scalar sound field.

  • 'power' — power pattern of the sensor or array defined as the square of the field pattern.

  • 'powerdb' — power pattern converted to dB.

Example: 'powerdb'

Data Types: char

Elevation angles, specified as the comma-separated pair consisting of 'Elevation' and a 1-by-P real-valued row vector. Elevation angles define where the array pattern is calculated.

Example: 'Elevation',[-90:2:90]

Data Types: double

Output Arguments

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Element directivity or pattern, returned as an P-by-N real-valued matrix. The dimension P is the number of elevation angles determined by the 'Elevation' name-value pair argument. The dimension N is the number of azimuth angles determined by the AZ argument.

Examples

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Plot an elevation cut of directivity of an isotropic hydrophone at 45° azimuth. Assume the signal frequency is 3 kHz. First, set up the hydrophone parameters.

fc = 3e3;
hydrophone = phased.IsotropicHydrophone('FrequencyRange',[1,10]*1e3, ...
    'VoltageSensitivity',[-100,-90,-100]);
patternElevation(hydrophone,fc,45)

Plot a smaller range of elevation angles using the Elevation parameter.

patternElevation(hydrophone,fc,45,'Elevation',-20:20)

More About

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Introduced in R2017a