California Microwave began leasing its hangar and office space near Washington County Regional Airport in February 1996.
The earlier M-1 and M-2 aircraft were modified last summer at California Microwave's former Martin State Airport operation east of Baltimore, Weaver said.
All three aircraft are capable of monitoring communications and tracking movement the size of a person from 10,000 feet then transmitting information to the ground in real time, he said.
However, the M-3 has improved capabilities, including greater resolution and the ability to make photo-like images of what's being picked up on radar, Weaver said.
The fourth and fifth aircraft in the series - in the midst of their makeovers at the hangar - will include even more improvements, like color cameras instead of black-and-white, he said.
The M-3 will join the M-1 and M-2 in Korea in October, said Lt. Col. Bruce Jette, project manager on the Army end.
The planes are used on a daily basis to monitor activity in the demilitarized zone between North Korea and South Korea, Jette said.
They've proven themselves a valuable asset in intelligence gathering, he said.
They work so much better than their predecessors in gathering tactical information that 13 analysts are needed on the ground now instead of just one previously, Jette said.
Full use of the aircraft's capabilities is still being explored, he said.
"The challenge is how creative we can be," Jette said. "Our soldiers are very creative."
U.S. Rep. Roscoe G. Bartlett, R-Md., commended California Microwave and its workers for helping boost national security while at the same time attesting to the high quality of the region's work force.
"You have made our advertisement of what business is like in Western Maryland a reality," Bartlett said.
California Microwave has plans to expand its Hagerstown operation into an adjacent building to accommodate C-130 aircraft and helicopter projects, Weaver said.
He said a mix of permanent and temporary workers will be hired for the jobs.
The company has about 100 workers in Hagerstown now, Weaver said.
Only 15 of them were moved from the company's Baltimore operation, he said.