The test article analyzed in the Benefield Anechoic Facility is comprised of the main fuselage of the next generation Global Hawk unmanned aerial vehicle.

In the nose section of the fuselage, it includes the avionics suite containing a high power satellite communication transmitter and a payload of extremely sensitive signals intelligence receiver processor systems known as the Advanced Signals Intelligence Payload.

Because these systems are positioned very close to each other in the front of the vehicle, the potential to cause electromagnetic interference between the two systems is high.

Only the Benefield Anechoic Facility is ideally suited for this type of testing because it provides an extremely quiet and no-reflective radio frequency environment so that sensitive measurements of interfering signals can be made.

The facility is the largest of its kind in the world, capable of testing the largest aerial weapon systems in the U.S. inventory.

The Benefield Anechoic Facility test team, led by 2nd Lt. Michael Stackhouse, 772nd Test Squadron electronics warfare test engineer, designed and implemented an antenna isolation measurement system that controls the Global Hawk satellite communication transmit antenna while simultaneously collecting RF data from the Advanced Signals Intelligence Payload receiver to verify the effectiveness of electromagnetic interference mitigation treatments installed on the vehicle.

The measurement system, created by Dave Mulvey and Justin Cobbs, is capable of a multitude of RF measurements in a short amount of time, allowing Northrop-Grumman test engineers to have graphic plots available to them to immediately analyze the data and make real-time decisions on the effectiveness of the electromagnetic interference treatments.

"Without this antenna isolation measurement system and people like Mulvey and Cobbs, we'd really have a difficult time supporting customers coming to our facility for electromagnetic interference troubles," Stackhouse said.

"We have an outstanding electromagnetic interference team here at the Benefield Anechoic Facility � they're highly competent at what they do and they're continuously working towards improving the unique capability of the facility to help defend this nation," he noted.

Northrop Grumman senior electromagnetic interference engineer, Dick Hohol, is supporting the test with engineers Monty Hall and Chuck Wilkerson from the Unmanned Systems Operation in Rancho Bernardo, Calif.

The team also received technical support from Rocky Furton of the Northrop Grumman Antelope Valley Manufacturing Facility.

"The Benefield Anechoic Facility enables us to perform highly accurate and repeatable measurements of antenna to antenna RF coupling in an environment representative of flight," Hohol said.

"Without a facility like the Benefield Anechoic Facility, it would be necessary to conduct extensive flight testing on the Global Hawk to identify electromagnetic interference issues and even further testing to verify the performance of any mitigation treatments," he explained.

This test of the Global Hawk unmanned aerial vehicle is one of a series of evaluations of this major intelligence gathering weapon system at the facility.

Tests, such as this one on the Global Hawk, enhance overall warfighter capability by minimizing the electromagnetic interference effects on the vehicle and help maximize the reliability and accuracy of data provided to combatant commanders in the field by the Advanced Signals Intelligence Payload SIGINT system so they're able to make better decisions in real time.

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