  This paper considers the optimization problems that arise to coordinate a
tandem between a mothership vehicle and a fleet of drones. %more than one
drone. Each drone can be launched from the mothership to perform an operation.
After completing the operations the drones return to the mothership to recharge
batteries and to be ready for a new operation. Operations consist on
(partially) visiting graphs with given lengths to deliver some service or to
perform some surveillance/inspection activity. The goal is to minimize the
overall weighted distance traveled by the mothership while satisfying some
requirements in terms of percentages of visits to the target graphs. In all
cases, we develop exact formulations resorting to mixed integer second order
cone programs that are compared on a testbed of instances to assess their
performance. We also develop a matheuristic algorithm that provides reasonable
solutions. Computational experiments show the usefulness of our methods in
different scenarios.
