The future of military tech is supposedly hypersonic missiles, stealth drones and suicide drones. I'm going with large-scale air force experiments with a new line of drones, possibly with a 'psy-op' angle. While the Democrats sabotage everything possible for the upcoming Orange-Man-Bad presidency (such as selling off portions of the border wall), they want to distract people with 'mysterious' unidentified aerial phenomena.
There be aliens/Iranian motherships launching drone squadrons/Chinese stealth balloons afoot.
(I haven't really spent much thought on this. In case you haven't noticed. ;) )
The reason they give exactly squares with what they've been doing. Assuming they're telling the truth, they obviously would test it over all kinds of terrain. Sometimes even the government tells the truth.
Not that the idea of drone swarms being able to 3D map your town and signature tracking is pleasant.