  This paper investigates a movable-antenna (MA) array empowered integrated
sensing and communications (ISAC) over low-altitude platform (LAP) system to
support low-altitude economy (LAE) applications. In the considered system, an
unmanned aerial vehicle (UAV) is dispatched to hover in the air, working as the
UAV-enabled LAP (ULAP) to provide information transmission and sensing
simultaneously for LAE applications. To improve the throughput capacity and
meet the requirement of the sensing beampattern threshold, we formulate a data
rate maximization problem by jointly optimizing the transmit information and
sensing beamforming, and the antenna positions of the MA array. Since the data
rate maximization problem is non-convex with highly coupled variables, we
propose an efficient alternation optimization based algorithm, which
iteratively optimizes parts of the variables while fixing the others. Numerical
results show the superiority of the proposed MA array-based scheme in terms of
the achievable data rate and beamforming gain compared with two benchmark
schemes.
