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sarnoiserefl

Noise equivalent reflectivity of SAR

    Description

    example

    neq = sarnoiserefl(freq,freqref,imgsnr,sigmaref) computes the noise equivalent reflectivity.

    neq = sarnoiserefl(freq,freqref,imgsnr,sigmaref,n) specifies a frequency-dependent proportionality factor that depends upon the target characteristics.

    Examples

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    Estimate the noise equivalent reflectivity of a side-looking SAR operating at a frequency of 16 GHz for a target reflectivity of –25 dB at the Ku band (nominally 16.7 GHz) and to form an image having an SNR of 30 dB.

    f = 16e9;
    sigmaref = -25;
    fref = 16.7e9;
    snr = 30;

    Convert the target reflectivity to linear units. Compute the noise equivalent reflectivity.

    neq = sarnoiserefl(f,fref,snr,db2pow(sigmaref))
    neq = -55.1860
    

    Input Arguments

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    Radar frequency in hertz, specified as a positive real scalar or a vector.

    Data Types: double

    Nominal reference frequency in hertz, specified as a positive real scalar.

    Data Types: double

    Image signal-to-noise ratio (SNR) of the SAR in decibels, specified as a real scalar or a vector.

    Data Types: double

    Reflectivity at nominal reference frequency in square meters per square meter, specified as a positive real scalar.

    Data Types: double

    Frequency-dependent proportionality factor, specified as a real scalar. For distributed targets, n varies between 0 and 1. For nondistributed targets, n is a positive real scalar.

    Data Types: double

    Output Arguments

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    Noise equivalent reflectivity in decibels, returned as a matrix. The rows of neq correspond to the frequency values in freq. The columns of neq correspond to the image SNR values in imgsnr.

    Extended Capabilities

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

    Introduced in R2021a