Multisensor, multisite tracking filter

A fusion filter has been designed for the tracking of airborne targets over a spherical Earth which can accommodate different sensor types at different geographical sites. It is assumed that sensor contacts are exchanged between sites in a timely fashion and all sensor contacts from the same object update the track filter. Registration and correlation mechanisms are assumed to be in place so that only sensor contacts derived from target A update the master track associated with target A. The filter is updated by one scalar measurement quantity at a time: either slant range, bearing angle, elevation angle or Doppler (i.e. range rate) from a local or remote sensor. This feature considerably simplifies the filter equations and allows the easy mixture of different sensor types. Performance of this filter is demonstrated with 2D, 3D and 4D sensors at either one or two sites and manoeuvring or nonmanoeuvring target trajectories. The filter is general enough to allow the localisation of a target in three dimensions with only contacts from a single unstabilised 2D sensor on a rolling and pitching marine platform