Image showing the PLGRM technology in action. The system includes a laser tracker (left), portable network analyzer, mobile base and lift kit, and collaborative robot with probe (center). Less anechoic foam (black) is required based on system design. (Image: NASA)

Testing aircraft antennas is challenging since optimal tests are made after antenna installation. Aircraft are often taken to anechoic antenna test facilities which create long lead times, transportation hassle, and very high costs. Portable alternatives exist but often have compromised testing fidelity. Innovators at the NASA Glenn Research Center have developed the PLGRM system, which allows an installed antenna to be characterized in an aircraft hangar. All PLGRM components can be packed onto pallets, shipped, and easily operated.

The PLGRM system is designed for in-situ antenna measurements at a remote site. Components include a collaborative robot arm mounted on a vertical lift and a laser tracker, each on a mobile base. These components enable scanning of a surface larger than the reach of the robot. To accomplish this, the robot first collects all points within its reach, then the system is moved and the laser tracker is used to relocate the robot before additional points are captured.

Safety, collision avoidance, and planning aspects are combined to effectively characterize such antennas. Software-defined triggering is also a feature for flexible integration of network analyzers and antenna controllers. Laser tracking is used over photogrammetry to provide position feedback with higher speed and lower latency that facilitates online control of the robotic arm.

While collecting the antenna radiation data, the system uses pulsed measurements and time gating to remove unwanted reflections. This lowers the requirement for fully surrounding the test area in anechoic foam. The system also accommodates the possibility of “dirty power” that may be found at any given host facility.

The flexibility and portability of this system while maintaining precision and accuracy are what make PLGRM unique. It can be deployed by only two people and can be powered by standard 110-volt wall outlets making it simple to implement. While developed for aerospace, PLGRM can be used to characterize antenna systems across a range of applications. Extending applications beyond just antenna analysis may also be possible.

NASA is actively seeking licensees to commercialize this technology. Please contact NASA’s Licensing Concierge at This email address is being protected from spambots. You need JavaScript enabled to view it. or call at 202-358-7432 to initiate licensing discussions. For more information, visit here .