Системная модель однопозиционной радиолокационной системы с

function calcParams()

    function albersheim(pd, pfa, N)
        A = log(0.62/pfa)
        B = log(pd/(1-pd))
        ABfactor = (A + 0.12*A*B + 1.7*B)
        N1 = 1/sqrt(N)
        N2 = (6.2+4.54/sqrt(N+0.44))/10
        snr = N1*ABfactor^N2
        snr = (10 .*log10(snr)+300)-300
    end

    function systemp(nf :: Number,reftemp :: Number = 290)
        nf >= 0 || error("Invalid input")
        nfLinear = db2pow(nf); 
        stemp = reftemp*(nfLinear); # Kelvin
        return stemp
    end

    function noisepow(nbw :: Number, nf :: Number = 0, reftemp :: Number = 290)
        B =  1.380649e-23
        npow =  B * systemp(nf,reftemp) * nbw
        return npow 
    end

    function FreeSpacePathLoss(R, lambda)
        typeof(lambda) <: Array ? lambda = lambda : lambda = [lambda]
        typeof(R) <: Array ? R = R : R = [R]
        L = Array(4π*R[:] .* ((1 ./ lambda[:]')))

        for it ∈ eachindex(L)
            if L[it] < 1
                L[it] = 1
            end
        end

        return 20log10.(length(L) == 1 ? L[1] : L)
    end

    function pow2db(y)
        all(y .<= 0) && error("Invalid input")
        return (10 .*log10(y)+300)-300
    end
    function db2pow(ydB)
        return  10 .^(ydB/10)
    end
    function aperture2gain(rcs, lambda)
        g = 4pi*rcs / (lambda^2)
        g = pow2db(g)
        return g
    end

    
    # Environment
    propSpeed = 299792458               # Propagation speed
    fc = 1e10                           # Operating frequency
    lambda = propSpeed/fc               # Length wave

    # Constraints
    
    maxRange = 5000                     # Maximum unambiguous range
    rangeRes = 50                       # Required range resolution
    pd = 0.9                            # Probability of detection
    pfa = 1e-6                          # Probability of false alarm
    tgtRcs = 1                          # Required target radar cross section
    numPulseInt = 10                    # Integrate 10 pulses at a time
    
   # Waveform parameters
    
    pulseBw = propSpeed/(2*rangeRes)    # Pulse bandwidth
    pulseWidth = 1/pulseBw              # Pulse width
    prf = propSpeed/(2*maxRange)        # Pulse repetition frequency
    fs = 2*pulseBw

    # Transmitter parameters

    snrMin = albersheim(pd, pfa, numPulseInt)      
    txGain = 20
    peakPower = ((4*pi)^3*noisepow(1/pulseWidth)*maxRange^4* db2pow(snrMin))/(db2pow(2*txGain)*tgtRcs*lambda^2)

    # Matched filter parameters

    matchingCoeff = [1, 1]
    # Delay introduced due to filter

    matchingDelay = size(matchingCoeff,1)-1;
    
    # Time varying gain parameters 
    fastTimeGrid = Vector(0:1/fs:(1/prf-1/fs))
    rangeGates = fastTimeGrid.*propSpeed/2; 
    metersPerSample = rangeGates[2];
    rangeOffset = -rangeGates[2]*matchingDelay;
    
    
    rangeLoss = 2FreeSpacePathLoss(rangeGates,lambda);     
    referenceLoss = 2FreeSpacePathLoss(maxRange,lambda);


   # Radar parameters
    targetRcs = [0.6 2.2 1.05 .5]
    targetPos = [1988.66 3532.630 3845.04 1045.04;0 0 0 0 ; 0 0 0 0 ]
    targetVel = zeros(3,4)

    return  (propSpeed = propSpeed ,
            fc =  fc,
            lambda = lambda,
            pulseBw = pulseBw,
            prf = prf,
            fs = fs,
            txGain = txGain,
            peakPower = peakPower,
            matchingCoeff = matchingCoeff,
            metersPerSample = metersPerSample,
            rangeOffset = rangeOffset,
            rangeLoss = rangeLoss,
            referenceLoss = referenceLoss,
            targetRcs = targetRcs,
            targetPos = targetPos,
            targetVel = targetVel)
end