Main Content

radareqsarrng

Maximum detectable range using SAR equation

Since R2021a

collapse all in page

    Syntax

    rng = radareqsarrng(lambda,snr,pt,tau,rnggain,azgain)
    rng = radareqsarrng(lambda,snr,pt,tau,rnggain,azgain,Name,Value)

    Description

    rng = radareqsarrng(lambda,snr,pt,tau,rnggain,azgain) returns the maximum detectable range for a SAR.

    example

    rng = radareqsarrng(lambda,snr,pt,tau,rnggain,azgain,Name,Value) specifies additional options using name-value arguments.

    example

    Examples

    collapse all

    Open Live Script

    Estimate the range for a side-looking SAR imaging a target with a radar cross-section (RCS) of 1 m2. The radar operates at a frequency of 5.3 GHz and has a peak power of 5 kW. The SAR uses a rectangular waveform with a pulse width of 0.05 microseconds. The antenna gain is 30 dB and the minimum detectable SNR is 30 dB. The range processing gain is 29.8 dB and the azimuth processing gain is 42.7 dB. Assume zero losses. 

    lambda = freq2wavelen(5.3e9);
pt = 5e3;

tau = 0.05e-6;

gain = 30;
SNR = 30; 

rnggain = 29.8;
azgain = 42.7;

    Compute the maximum detectable range. Express the result in kilometers.

    rng = radareqsarrng(lambda,SNR,pt,tau,rnggain, azgain,'Gain', gain,'UnitStr','km')
    rng = 
205.6978

    Input Arguments

    collapse all

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

    Data Types: double

    Required signal-to-noise ratio (SNR) in decibels, specified as a real scalar or a vector.

    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 pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

    Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

    Example: 'Ts',293,'Gain',12

    Target radar cross-section in square meters, specified as a scalar or a vector. radareqsarrng 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, radareqsarrng 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

    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

    Unit of range length, specified as 'm' (meter), 'km' (kilometer), 'mi' (statute mile), or 'nmi' (nautical mile).

    Data Types: char | string

    Output Arguments

    collapse all

    Maximum detectable range, returned as a column vector expressed in the units specified using UnitStr. For bistatic radars, each element of rng is the geometric mean of the range from the transmitter to the target and the range from the target to the receiver.

    Extended Capabilities

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

    Version History

    Introduced in R2021a

    See Also

    | | |