Surveillance is an important application for unmanned aerial vehicles (UAVs). The sensed information often has high priority and it must be made available to human operators as quickly as possible. Due to obstacles and limited communication range, it is not always possible to transmit the information directly to the base station. In this case, other UAVs can form a relay chain between the surveillance UAV and the base station. Determining suitable positions for such UAVs is a complex optimization problem in and of itself, and is made even more diﬃcult by communication and surveillance constraints.
To solve diﬀerent variations of ﬁnding positions for UAVs for surveillance of one target, two new algorithms have been developed. One of the algorithms is developed especially for ﬁnding a set of relay chains oﬀering diﬀerent trade-oﬀs between the number of UAVsand the quality of the chain. The other algorithm is tailored towards ﬁnding the highest quality chain possible, given a limited number of available UAVs.
Finding the optimal positions for surveillance of several targets is more diﬃcult. A study has been performed, in order to determine how the problems of interest can besolved. It turns out that very few of the existing algorithms can be used due to the characteristics of our speciﬁc problem. For this reason, an algorithm for quickly calculating positions for surveillance of multiple targets has been developed. This enables calculation of an initial chain that is immediately made available to the user, and the chain is then incrementally optimized according to the user’s desire.