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radareqsarsnr

Signal-to-noise ratio of SAR image

    Description

    example

    imgsnr = radareqsarsnr(r,lambda,pt,tau,rnggain,azgain) returns the SAR image signal-to-noise ratio (SNR).

    example

    imgsnr = radareqsarsnr(r,lambda,pt,tau,rnggain,azgain,Name,Value) specifies additional options using name-value arguments.

    Examples

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    Estimate the image SNR for a SAR operating in broadside at a frequency of 5.3 GHz and 5 kW peak power to form an image of a target at 50 km. Assume an RCS of 1 m2 and rectangular waveform with a bandwidth of 0.05 microseconds. The range processing gain is 29.8 dB and the azimuth processing gain is 42.7 dB. Assume no losses.

    lambda = freq2wavelen(5.3e9);
    pt = 5e3;
    r = 50e3; 
    
    tau = 0.05e-6;
    
    rnggain = 29.8;
    azgain = 42.7;

    Compute the image SNR.

    snr = radareqsarsnr(r,lambda,pt,tau,rnggain,azgain)
    snr = 34.5704
    

    Input Arguments

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    Range to target in meters, specified as a scalar, a column vector, a 1-by-2 row vector, or a 2-column matrix.

    • Specify this argument as a scalar or a column vector for a monostatic radar.

    • Specify this argument as a 1-by-2 row vector or as a 2-column matrix for a bistatic radar.

      • The first element or column corresponds to the range from the transmitter to the target.

      • The second element or column corresponds to the range from the target to the receiver.

    Data Types: double

    Wavelength of radar operating frequency in meters, specified as a positive real scalar.

    Data Types: double

    Transmitter peak signal power in watts, specified as a positive real scalar or a vector.

    Data Types: double

    Pulse width at the antenna port in seconds, specified as a positive real scalar.

    Data Types: double

    SNR gain due to range processing in decibels, specified as a real scalar.

    Data Types: double

    SNR gain due to azimuth processing in decibels, specified as a 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: 'Ts',293,'Gain',12

    Target radar cross-section in square meters, specified as a scalar or a vector. radareqsarsnr assumes a nonfluctuating target (Swerling case 0).

    Data Types: double

    System noise temperature in kelvins, specified as a positive scalar.

    Data Types: double

    Antenna gain in decibels, specified as a scalar or 1-by-2 row vector.

    • If you specify this argument as a two-element vector, the first element represents antenna transmit gain and the second element represents the antenna receive gain.

    • If you specify this argument as a scalar, radareqsarsnr assumes the antenna has equal transmit and receive gains.

    Data Types: double

    System loss in decibels, specified as a scalar or a vector.

    Data Types: double

    Atmospheric absorption loss in decibels, specified as a scalar, a column vector, a 1-by-2 row vector, or a 2-column matrix.

    • Specify this argument as a scalar or a column vector to represent the atmospheric absorption loss for a one-way path.

    • Specify this argument as a 1-by-2 row vector or as a 2-column matrix to represent a transmit path and a receive path.

      • The first element or column corresponds to the atmospheric absorption loss for the transmit path.

      • The second element or column corresponds to the atmospheric absorption loss for the receive path.

    Data Types: double

    Propagation factor in decibels, specified as a scalar, a column vector, a 1-by-2 row vector, or a 2-column matrix.

    • Specify this argument as a scalar or a column vector to represent the propagation factor loss for a one-way path.

    • Specify this argument as a 1-by-2 row vector or as a 2-column matrix to represent a transmit path and a receive path.

      • The first element or column corresponds to the propagation factor for the transmit path.

      • The second element or column corresponds to the propagation factor for the receive path.

    Data Types: double

    Custom factor in decibels, specified as a scalar or a vector. This argument contributes to the received signal energy and can include other factors.

    Data Types: double

    Output Arguments

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    SAR image signal-to-noise ratio in decibels, returned as a column vector.

    Extended Capabilities

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

    Introduced in R2021a