Attach the mini-drone to a helium filled ... red balloon (just to rhyme with the well-known song), or some better tactical color.
This would somewhat alleviate the energy expenditure to maintain lift and prolong the flight time. The motors may selectively cut off based on present state of inertia. This may be all possible due to relatively small weight of such drones. Sure this would preclude operation in storm winds.
It's a question of mission requirements. Drones of these sizes are more like a floating/hidden eye/ear than anything of direct offense. Besides, it does not need to transmit at all, just record and deliver back on homing beacon.
I think another issue with the balloon would be helium leakage, having tanks and the ability to refill them on hand, fill valves etc adding weight. Not deal breakers, but complicators. I think your point is more direct, although I wonder why something like this wouldn't be appropriate for surveillance of a fixed area etc.
This would somewhat alleviate the energy expenditure to maintain lift and prolong the flight time. The motors may selectively cut off based on present state of inertia. This may be all possible due to relatively small weight of such drones. Sure this would preclude operation in storm winds.
It's a question of mission requirements. Drones of these sizes are more like a floating/hidden eye/ear than anything of direct offense. Besides, it does not need to transmit at all, just record and deliver back on homing beacon.