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sarazgain

SAR azimuth processing gain

    Description

    example

    ag = sarazgain(r,lambda,v,azres,prf) computes the azimuth processing gain due to the coherent integration of multiple pulses, either by presumming or through actual Doppler processing.

    example

    ag = sarazgain(___,Name,Value) specifies additional options using name-value arguments. Options include the azimuth impulse broadening factor and the Doppler cone angle.

    Examples

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    Compute the azimuth processing gain of a side-looking airborne SAR operating in broadside at a wavelength of 0.05 m with a sensor velocity of 100 m/s and a PRF of 2 kHz for a target at 5 km. The cross-range resolution of the image is 1.5 m. Assume an azimuth broadening factor of 1.2 and a nonideal azimuth filtering loss of 1.2 dB.

    lambda = 0.05;
    PRF = 2e3;
    R = 5e3;
    res = 1.5;
    v = 100;
    La = 1.2;
    azb = 1.2;

    Compute the azimuth processing gain.

    azgain = sarazgain(R,lambda,v,res,PRF,'AzimuthBroadening',azb, ...
        'AzimuthFilteringLoss', La)
    azgain = 31.8103
    

    Input Arguments

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    Range from target to antenna in meters, specified as a positive real scalar or a vector.

    Data Types: double

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

    Data Types: double

    Sensor velocity in meters per second, specified as a positive real scalar.

    Data Types: double

    Image azimuth or cross-range resolution in meters, specified as a positive real scalar.

    Data Types: double

    Radar pulse repetition frequency (PRF) in hertz, specified as a positive real scalar.

    Data Types: double

    Name-Value 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.

    Example: 'AzimuthBroadening',1.2,'ConeAngle',60

    Azimuth impulse broadening factor due to data weighting or windowing for sidelobe control, specified as a positive real scalar. This argument expresses the actual –3 dB mainlobe width with respect to the nominal width. Typical window functions like hamming and hann exhibit values in the range from 1 to 1.5.

    Data Types: double

    Reduction in signal-to-noise ratio (SNR) gain in decibels, specified as a nonnegative scalar. This argument corresponds to the loss with respect to the ideal gain. Typical window functions like hamming and hann exhibit losses on the order of 1 dB. The argument defaults to 0, which assumes a rectangular window.

    Data Types: double

    Doppler cone angle in degrees, specified as a scalar in the range [0, 180]. This argument identifies the direction toward the scene relative to the direction of motion of the array.

    Data Types: double

    Output Arguments

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    Azimuth processing gain, returned as a matrix. The rows of ag correspond to the range values in r and its columns correspond to the wavelength values in lambda.

    Extended Capabilities

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

    Introduced in R2021a