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mtiloss

Losses due to moving target indicator (MTI) processing

    Description

    [LI,LV] = mtiloss(PD,PFA,N) computes integration loss, LI, and velocity response loss, LV, due to MTI processing with a two-pulse (first-order) canceller given the probability of detection, PD, probability of false alarm, PFA, and the number of received pulses available at the MTI input, N.

    The function computes the loss assuming you are using a square-law detector and a nonfluctuating target.

    example

    [LI,LV] = mtiloss(PD,PFA,N,M) computes losses due to MTI processing with an M-pulse canceler.

    example

    [LI,LV] = mtiloss(PD,PFA,N,M,SW) computes MTI losses for radar echoes received from a chi-squared distributed target specified using the Swerling case number, SW.

    [LI,LV] = mtiloss(___,Name,Value) computes MTI losses using one or more name-value arguments. For example, [LI,LV] = mtiloss(0.64,1e-12,8,'Method','Batch') calculates LI and LV for MTI with batch processing. Specify the name-value arguments after any of the input arguments from the previous syntax.

    example

    [___,LBP] = mtiloss(___) computes the blind phase loss LBP only when you set IsQuadrature name-value argument to false.

    Examples

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    Calculate the velocity response loss for an MTI processing with a three-pulse canceler, with the probability of false alarm of 1e-6 and 24 pulses received from a nonfluctuating target.

    PFA = 1e-6; 
    N = 24;     
    M = 3;      
    PD = 0.1:0.01:0.99;
    [~,LV] = mtiloss(PD,PFA,N,M);

    Plot the velocity response loss.

    plot(PD,LV)
    xlabel('Probability of Detection')
    ylabel('Loss (dB)')
    title('Velocity Response Loss for MTI with a Three-Pulse Canceler')
    grid on

    Figure contains an axes. The axes with title Velocity Response Loss for MTI with a Three-Pulse Canceler contains an object of type line.

    Compute the noise correlation loss for MTI processing with a three-pulse canceler. Assume that the desired probability of detection is 0.9, the probability of false alarm is 1e-6, and 24 pulses are received from a Swerling 1 target.

    PD = 0.9;   
    PFA = 1e-6;
    N = 24;     
    M = 3;      
    LI = mtiloss(PD,PFA,N,M,'Swerling1')
    LI = 2.0811
    

    Compute the blind phase loss for an MTI with a two-pulse canceler with the desired probability of detection of 0.95, the probability of false alarm of 1e-8, and 10 pulses received from a nonfluctuating target.

    PD = 0.95;   
    PFA = 1e-8;  
    N = 10;      
    [~,~,LBP] = mtiloss(PD,PFA,N,'IsQuadrature',false)
    LBP = 2.3881
    

    Input Arguments

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    Probability of detection in the range [0.1,0.999999], specified as a positive scalar or as a length-J vector with each element in the range [0.1,0.999999] .

    Probability of false alarm, specified as a positive scalar in the range [1e-15,1e-3] or as a length-K vector with each element in the range [1e-15,1e-3] .

    Number of received pulses available at the input of the MTI, specified as a positive integer equal to or greater than 2.

    Number of pulses in an M-pulse MTI canceler, specified as a positive integer in the range [2,15]. The M-pulse canceler is constructed using cascading M-1 two-pulse cancellers.

    Swerling case number, specified as one of these

    • 'Swerling0'

    • 'Swerling1'

    • 'Swerling2'

    • 'Swerling3'

    • 'Swerling4'

    • 'Swerling5'

    .

    Name-Value Pair 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: [LI,LV] = mtiloss(0.7,1e-8,10,'Method','Batch')

    Pulse processing method, specified as a character vector or string scalar.

    • If you set 'Method' to 'Sequential', the received pulses are processed sequentially resulting in N-M pulses at the output of the pulse canceler.

    • If you set 'Method' to 'Batch', the N received pulses are divided into N/(M+1) batches, which are processed separately resulting in N/(M+1) pulses at the output of the MTI.

    Example: [LI,LV] = mtiloss(0.7,1e-9, 8,'Method','Batch')

    Quadrature-channel (vector) or single-channel MTI processing, specified as a logical value.

    • If you set 'IsQuadrature' to true, the MTI processing has two parallel cancelers for the I and Q components. By default, the function sets 'IsQuadrature' to true and the blind phase loss output is zero.

    • If you set 'IsQuadrature' to false, only the I or the Q channel is used for MTI resulting in blind phase loss LBP.

    Example: [LI,LV,LBP] = mtiloss(0.9,1e-8,10,'IsQuadrature',false)

    Output Arguments

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    Integration loss due to correlation in the noise samples at the output of the MTI filter, returned as a J-by-K matrix in dB with rows corresponding to the values in PD and columns to the values in PFA.

    Velocity response loss due to target velocity lying near the null of the MTI pulse canceler, returned as a J-by-K matrix in dB with rows corresponding to the values in PD and columns to the values in PFA.

    Blind phase loss, returned as a J-by-K matrix in dB with rows corresponding to the values in PD and columns to the values in PFA. LBP is computed only when you set the value of the 'IsQuadrature' argument to false.

    Introduced in R2021a