These operate at low altitude and are used for gathering intelligence, surveillance, target acquisition and reconnaissance operations.

He also indulged in aerotrekking — a dangerous hobby of his own invention that involved flying unlicensed aircraft at low altitude.

Flying at low altitude made the pilots vulnerable even to light anti-aircraft fire.

We are trying to find somewhere at low altitude that we can use as a self-catering base.

Conditions for detailed telescopic observations are poor due to the planets' low altitude, but things will improve as spring turns into summer.