In recent years, the feasibility of using continuous-active-sonar (CAS) transmissions as an alternative to pulsed-active-sonar (PAS) transmissions has been explored. A CAS system transmits waveforms with high-duty-cycle (HDC) near or equal to 100%. CAS offers potential improvements over short-burst PAS signals by providing an order-of-magnitude or more increase in the number of detection opportunities with a faster revisit rate for improved target localization and holding. Much of the previous work has focused on understanding the performance benefits of CAS as well as the differences between PAS and CAS performance both at the output of the processing chain and at the output of a multitarget tracking algorithm. In this paper we explore a synergistic use of PAS and CAS transmissions occurring in parallel, at the same time. The LCAS’ 15 experiment provided a data set that included simultaneous transmissions of both PAS and CAS waveforms from a monostatic sonar. Signal and information processing were applied to both the PAS and the CAS received signals. A sonar tracking algorithm was modified to accept detection contacts from both PAS and CAS and provides various PAS-CAS fusion rules/schemes for evaluation. The tracker was applied to the sea trial data for PAS-only and CAS-only which establishes baseline cases, which are compared with other fusion cases that combined PAS and CAS waveform scans. The analysis shows encouraging results with synergistic improvements in tracker metrics by achieving the best performance (and avoiding the worst performance) of either PAS or CAS operating independently. A fusion rule with PAS track initiation /confirmation and CAS track termination provided the longest track holding and fewest false tracks, and provides the lowest uncertainty in target localization error.

This paper provides an overview of the special session on multistatic sonar and radar tracking at FUSION 2006. This includes background on the multistatic tracking working group, a brief description of the datasets and trackers that compose this working group at present, and a detailed discussion of a proposed set of tracker performance metrics. We identify a number of issues associated with performance assessment for target tracking. We conclude with recommendations for continued performance assessment of multistatic trackers

This paper provides a brief description and performance results for the multistatic sonar trackers developed at NURC. Our analysis is based on common data distributed as part of the multistatic tracking working group (MSTWG), as well as sea trial data. We find that the nearest-neighbor tracker provides reasonable performance in benign environments, while the centralized and distributed MHT trackers have complementary strengths in more challenging scenarios

Distributed multistatic active sonar systems have the potential to greatly improve surveillance capability against threat submarines. The geometric diversity of such systems provides an increased number of complementary detection opportunities to counter the underwater threat. The utilization of both Doppler sensitive and insensitive waveforms within such a multistatic network further improves the detection diversity and provides a more robust surveillance capability. This paper describes the issues relevant to achieve this detection diversity, and shows the potential improvements of this approach. A simplified sonar signal excess model is described, which provides a capability to evaluate distributed sensor placements using both waveform types

This paper provides an overview of a multistatic sonar contact-data simulation approach and a dataset generated specifically for tracker algorithm evaluation by the multistatic tracking working group (MSTWG). A brief description of the simulation approach is given, which includes simple sonar equation modeling, resulting in sensor-to-sensor target fading effects, as well as contact localization modeling. We describe the methodology by which a single data set generated using this approach is suitable to evaluate multistatic tracker performance over a range of multi-sensor detection redundancy levels