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value

Infrared intensity at specified angle and frequency

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Syntax

irval = value(irsig,az,el)

Description

irval = value(irsig,az,el) returns the value of the IR intensity, irval, specified by the IR signature object, irsig, computed at the azimuth, az, and elevation, el. If the specified azimuth and elevation is outside of the region in which the IR signature is defined, the IR intensity is returned as -Inf in dBw/sr.

example

Input Arguments

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Radar cross-section signature, specified as an irSignature object.

Azimuth angle, specified as scalar or length-M real-valued vector. Units are in degrees. The az, el, and freq arguments must have the same size. You can, however, specify one or two arguments as scalars, in which case, the arguments are expanded to length-M.

Example: 30

Data Types: double

Elevation angle, specified as scalar or real-valued length-M vector. The az and el arguments must have the same size. You can, however, specify one or two arguments as scalars, in which case, the arguments are expanded to length-M. Units are in degrees.

Example: -4

Data Types: double

Output Arguments

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Infrared intensity, returned as a scalar or real-valued length-M vector. Units are in dBw/sr.

Examples

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Open Live Script

Create and display an IR intensity signature. The signature depends on azimuth and elevation.

Define the azimuth and elevation angle sample points.

az = -90:90;
el = [-30:30];

Create the IR intensity signature pattern.

pat = 50*cosd(2*el.')*cosd(az).^2;
irsig = irSignature('Pattern',pat,'Azimuth',az,'Elevation',el);

Display the IR pattern.

imagesc(irsig.Azimuth,irsig.Elevation,irsig.Pattern)
xlabel('Azimuth (deg)')
ylabel('Elevation')
title('Infrared Signature Pattern (dBw/sr)')

Figure contains an axes object. The axes object with title Infrared Signature Pattern (dBw/sr), xlabel Azimuth (deg), ylabel Elevation contains an object of type image.

Get the IR intensity value at 25 degrees azimuth and 10 degrees elevation.

value(irsig,25,10)
ans = 
38.5929

Get IR intensity value outside of the valid elevation span.

value(irsig,25,35)
ans = 
-Inf

Extended Capabilities

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

Version History

Introduced in R2018b