Northrop Grumman to Provide Relative Navigation Software and Ethernet Access to Navigation System for Air Force Refueling Program

Northrop Grumman Corporation's relative navigation solution has been selected by the U.S. Air Force for the Automated Aerial Refueling (AAR) program follow-on contract.

Relative navigation, the ability to measure the relative motions of two vehicles accurately and reliably, is critical to aerial refueling of unmanned vehicles. Northrop Grumman's solution provides a LN-251 inertial navigation system (INS) with Ethernet connectivity that runs relative navigation software.

"Northrop Grumman is proud to continue its support of the Air Force Research Laboratory as it matures relative navigation technology," said Charles Volk, vice president and chief technology officer of Northrop Grumman's Navigation Systems Division.

"The selection of Northrop Grumman by the Air Force demonstrates the quality of the LN-251 system, Northrop Grumman's achievements in relative navigation technology, and the company's ability to work collaboratively to deliver mission-enabling solutions."

"Northrop Grumman has been involved with AAR since it began and has supported all the test flights so far," said Alex Fax, director of positioning, navigation, and timing solutions for Northrop Grumman's Navigation Systems Division. "We played a critical role in the overall system integration of AAR, supported system architecture development and provided analysis for the program. The navigation system we develop will be supplied to the AAR Integrator Team."

"Relative navigation is a key enabler for capabilities that involve vehicles that must operate in close proximity," said Fax. "A relative navigation capability extends the operational effectiveness of unmanned vehicles by enabling aerial refueling and future carrier landings."

The AAR program demonstrates the capability of refueling unmanned aerial vehicles with the existing Air Force tanker fleet. The Air Force Research Laboratory successfully demonstrated the ability of the AAR system to autonomously execute aerial refueling maneuvers in close proximity to a tanker during flight tests in November 2007.

Initial flight tests scheduled for the next program phase will focus on integrating and characterizing multiple LN-251 units, with final flight tests planned prior to system delivery for use by the AAR Integrator Team.

During the earlier tests, Northrop Grumman's relative navigation software and fiber-optic INS provided the accuracy and the relative positioning information that enabled a Learjet modified to act as a surrogate UAV to maneuver autonomously near the tanker.

The LN-251 INS units contain a high performance navigation-grade fiber-optic gyro based inertial measurement unit that provides a compact and low noise precision navigation solution for the relative navigation applications. The LN-251 is easy to incorporate into new aircraft and avionics systems of existing aircraft. Its modular open architecture supports new applications and evolving requirements.