Tracking device with deferred activation and propagation of passive tracks

A tracking device configured to estimate a track for at least one possible target and configured to receive incoming measurements and to process measurements and tracks, said tracking device comprising:

• a storage and a computational device having a computational capacity and configured with:
• an association module configured to calculate an association between a measurement and a track;
• an output module configured to output a sequence of track updates from an assignment module;
• an assignment module configured to maintain a set of active tracks and, using the association module to calculate associations between active tracks and the incoming measurements, the calculated associations containing possible track updates, deciding which track updates to keep in the set of active tracks and which track updates to add to a set of passive tracks, the set of passive tracks comprises tracks which are not updated when new measurements are received at the tracker;
• the computational device being configured to:
• defer computations on the set of passive tracks until at least one passive track handling criterion is fulfilled,
• activate at least one passive track from the set of passive tracks and transfer the at least one passive track from the set of passive tracks to the set of active tracks by at least one of the computations,
• the tracking device further configured to divide all measurements into a set of considered measurements and a set of unconsidered set of measurements for each passive track;
• and comprising:
• a propagator module configured to propagate by the computations on the set of passive tracks, a selected passive track using the association module to calculate an association as a function of an unconsidered measurement and the selected passive track;
• adding the possible track update of the selected passive track and the unconsidered measurement to the set of passive tracks, and marking the measurement considered for both the selected passive track and the possible track update.