Lost at Sea: Multi-Searcher Multi-Target Search

This paper addresses the multi-searcher multi-target search problem in open ocean environments. It is a challenging problem as the searchers need to trade-off between the capture rate and capture time while accounting for uncertainties due to dynamic ocean environment in a large search region. We formulate the searcher to target allocation problem as an iterative bipartite task assignment problem with the cost function as a combination of the probability of finding the target and the time to travel to it. Additionally, we implement three search strategies which the searchers dynamically select based on the different phases of their search mission. These search strategies include, inward spiral search, outward spiral search and patrolling the circumference. We validate our proposed multi-searcher multitarget search algorithm in simulation with real-world environmental data for wind and current. Our experimental results suggest at least 98.5% of targets will be found within first 12 hours of the searchers' deployment.