Terrain obscuration managment for multiple ground target tracking

Multiple ground targets tracking with a GMTI (ground moving target indicator) sensor is considered a challenging problem in order to establish battlefield assessment. An IMM algorithm with a variable structure is adapted to the road network and used to track multiple manoeuvring ground targets. However, the case of undetected targets due to terrain elevation or Doppler obscuration was not taken into account in our tracking process. In this paper, we present our approach to track ground targets with the possibility for the target to be undetected. The perceivability probability is computed to update the estimated state and a "sentinel" concept is used to palliate the association ambiguities when several targets enter and exit the same terrain mask.