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rainscr

Signal-to-clutter ratio due to rain

    Description

    example

    scr = rainscr(lambda,rrcs,tgtrcs,t) returns the signal-to-clutter ratio (SCR) due to rain.

    example

    scr = rainscr(lambda,rrcs,tgtrcs,t,vbrain) specifies the rain velocity bandwidth.

    Examples

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    Estimate the signal-to-clutter-ratio due to rain of a side-looking airborne SAR. The SAR moves at 50 m/s in a direction orthogonal to the antenna boresight and operates at a frequency of 1.5 GHz. The rain rates are 0.25 mm/hr, 1 mm/hr, 4 mm/hr, and 16 mm/hr. The rain clutter volume is 20 m3. The SAR module has aperture processing length of 100 m. Assume the target RCS is 1 m2 and the velocity bandwidth of the rain is 4 m/s.

    v = 50;
    f = 1.5e9;
    lambda = freq2wavelen(f);
    
    rr = [0.25 1 4 16];
    vol = 20;
    
    L = 100;
    tgtrcs = 1;
    vbrain = 4;

    Compute the signal-to-clutter ratio. Use rainreflectivity and clutterVolumeRCS to compute the rain radar cross-section. Use sarinttime to compute the aperture collection interval.

    volref = rainreflectivity(f,rr);
    rrcs = clutterVolumeRCS(volref,vol);
    t = sarinttime(v,L);
    scr = rainscr(lambda,rrcs,tgtrcs,t,vbrain);

    Plot the signal-to-clutter ratio as a function of the rain rate.

    semilogx(rr,scr,'o-')
    xlabel('Rain Rate (mm/rr)')
    ylabel('Signal-to-Clutter Ratio (dB)')

    Figure contains an axes object. The axes object contains an object of type line.

    Input Arguments

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    Radar wavelength in meters, specified as a positive real scalar or a vector.

    Data Types: double

    Rain radar cross-section (RCS) in square meters, specified as a scalar or a vector.

    Data Types: double

    Target RCS in square meters, specified as a scalar.

    Data Types: double

    Aperture collection interval in seconds, specified as a positive real scalar.

    Data Types: double

    Rain velocity bandwidth in meters per second, specified as a positive scalar.

    Data Types: double

    Output Arguments

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    Signal-to-clutter ratio due to rain in decibels, returned as a matrix. The rows of scr correspond to the radar wavelength values in lambda. The columns of scr correspond to the rain RCS values in rrcs.

    Extended Capabilities

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

    Introduced in R2021a