Elbit Systems says it has successfully flight-tested its Hermes 450 and Hermes 900 unmanned aerial vehicles from one ground control station, greatly enhancing the operational flexibility of the long-range drones amid a growing global market for the aircraft.

The tests underlined how Israel's high-tech defense industry is developing a wide range of unmanned robot systems for air, land and sea. These include Nahshson, a remote-controlled land vehicle that can tote 2 tons of cargo.

This is an advanced variant of the Guardium robot vehicle developed by G-NIUS Unmanned Ground Systems, a joint venture by Elbit and state-owned Israel Aerospace Industries. The Guardium has been in operated by the Israeli military since 2008.

Elbit said the Hermes tests were conducted from the company's new universal ground control station using a single operator for both UAVs.

"Joint flight control and management of two different unmanned aircraft systems provides users with enhanced operational flexibility, adapting each UAS to a specific mission and enabling management of highly complex missions in diverse arenas," Elbit said.

The Hermes 450 is a tactical long-endurance UAV that is the backbone of the Israeli air force's drone fleet, with more than 200,000 operational flight hours.

It's capable of flying at altitudes up to 20,000 feet. The latest variant is quieter than its predecessors and carries a heavier payload.

The Hermes 900 has longer endurance, a silenced engine, a maximum altitude of 30,000 feet and a larger payload capacity of 770 pounds.

Israel's defense industry has become a major producer of UAVs, along with the United States.

According to Jacques Chemia, chief engineer of IAI's UAV division, "Israel is the world's leading exporter of drones, with more than 1,000 sold in 42 countries."

Under a ground-breaking April 2009 contract with Moscow, worth $53 million, IAI, flagship of Israel's defense industry, sold Russia 12 short-range Bird-Eye 400, I-View MK150 and long-range Searcher II UAVs.

It was Russia's first purchase of a foreign weapons system and emphasized its technology shortfall following the sharp reduction of spending on research and development in the 1990s when the Cold War ended.

That contract led to a $400 million deal between IAI and Russia's Oboronprom OPK Group in October under which the Russians will eventually manufacture the Heron 1, one of Israel's most advanced UAVs capable of strategic missions.

IAI has developed the more advanced Heron TP, dubbed the Eitan which is Hebrew for "Strong."

This long-range UAV weight 4.5 tons, has a wingspan of 86 feet -- about that same as a Boeing 737 airliner -- and can stay aloft for 20 hours at high altitude.

This unique UAV, a major technological breakthrough for the Israelis, has a 1,200 horsepower turbojet, a maximum altitude of 40,000 feet and can carry hundreds of pounds of equipment, such as high-resolution cameras, electronic surveillance systems and presumably weapons.

The Heron TP is capable of reaching Iran, although it's not known whether it has done so on surveillance missions, or whether it can be refueled in air.

The Hermes 900 is also reported to be able to reach Iran.

The ground-based robot systems are now widely deployed with the Israeli military. The Guardium has notched up thousands of operational hours since 2008.

The Nahshon, the latest UGV being developed by UGS, is able to operate on its own in combat zones. The Nahshon team believes it is close to producing a completely autonomous guidance system for the cargo vehicle.

Guardium and other UGVs are used to reinforce the remote-controlled gun and sensor towers or patrol areas along Israel's borders with troubled Lebanon and the Gaza Strip.

Amid the upheaval in Egypt that toppled President Hosni Mubarak, Israeli Prime Minister Binyamin Netanyahu ordered the construction of a security barrier along a 90-mile stretch of the border with Egypt to be speeded up.

This, originally intended to keep out illegal African immigrants, could have remote-control guard towers as well and be patrolled by UGVs.

Over recent years, the Israeli military has automated much of its security along the Lebanese and Gaza borders.

This includes the Sentry-Tech armored watchtowers, 15 feet high and 6 feet in diameter, that are topped with remote-control machine gun turrets and night-vision video cameras. The latest addition is radar that can penetrate fog.