... known¹

Estimation of K, using a Viterbi algorithm approach, is discussed in [20].

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... equations²

To simplify the discussion we assume linear state/measurement equations.

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... possible³

These assumptions allow for representation of unresolved targets as a combination of detections and missed detections.

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... is⁴

$\left( \begin{array}{c} A \\ B \end{array} \right)$represents the number of combinations of A things taken B at a time.

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... used⁵

Because each state represents all permutations of the corresponding Kmeasurements/missed-events, each path through the trellis represents a number of hypothesized track sets.

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