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Next: 18.4.5 Three-dimensional Tracking Up: 18.4.4 Two-dimensional Mono Tracking Previous: Two-dimensional Report Formation

Track Initialization

The algorithm described in Section 18.4.4 is only applicable for extending tracks which already exist in the track file. The creation of new entries is done by a separate track initiation function.

The track initiator involves little more than searches for nearly colinear triples of data over the last three scans. A triplet

two-dimensional datum, current scan
two-dimensional datum, prior scan
two-dimensional datum, two scans back

is a candidate new track if

where the cutoff is generally fairly loose (e.g., ). In addition, a number of simple heuristic cuts (maximum speed) are applied.

The initiator searches for all approximately linear triples over the last three scans, subject to the important additional restriction that no initiations to a particular item of the current data set are attempted if any established track (minimum age cut) already exists ending at that datum. The nominal complexity of the initiator is reduced to approximately by exploiting the sorted dature on the incoming data sets.

Guy Robinson
Wed Mar 1 10:19:35 EST 1995