An antenna includes a radiator and a reflector and has a radiation pattern that is based at least in part on a separation distance between the radiator and the reflector. The antenna includes a linkage configured to adjust the separation distance based at least in part on the altitude of the antenna. The resulting radiation pattern can be dynamically adjusted based on altitude of the antenna such that, while the antenna is aloft and the antenna is ground-facing, variations in geographic boundaries and intensity of the radiation received at ground level are at least partially compensated for by the dynamic adjustments to the radiation pattern.