  In this paper, we investigate joint resource allocation and trajectory design
for multi-user multi-target unmanned aerial vehicle (UAV)-enabled integrated
sensing and communication (ISAC). To improve sensing accuracy, the UAV is
forced to hover during sensing.~In particular, we jointly optimize the
two-dimensional trajectory, velocity, downlink information and sensing
beamformers, and sensing indicator to minimize the average power consumption of
a fixed-altitude UAV, while considering the quality of service of the
communication users and the sensing tasks. To tackle the resulting non-convex
mixed integer non-linear program (MINLP), we exploit semidefinite relaxation,
the big-M method, and successive convex approximation to develop an alternating
optimization-based algorithm.~Our simulation results demonstrate the
significant power savings enabled by the proposed scheme compared to two
baseline schemes employing heuristic trajectories.
