Raytheon has reached an important milestone in its production of its persistent surveillance towers. The Rapid Aerostat Initial Deployment system provides surveillance support for use in both war and peacetime. Now the US army has three hundred of them.

The Waltham, Massachusetts-based defense contractor said the towers support intelligence, surveillance and reconnaissance missions. They are used by the US military in Afghanistan and Iraq and are also used for domestic border surveillance - both in the United States and U.S. ally nations.

The towers use infrared sensors on an elevated stationary platform. Raytheon officials say the towers perform a crucial function in protecting American soldiers.

"Everyone working on the RAID program knows that what they do in providing unparalleled support to our customer plays a key role in making sure the system has the highest operational readiness for our warfighters" said Mike Staid, RAID senior program manager, in a statement.

The persistent surveillance towers are the product of a joint venture between academia, large and small business. The RAID system is produced in Andover, Mass., and Billerica, Mass. and in Huntsville, Ala.

Raytheon employes 72,000 employees worldwide.