Enhanced Sensor for Characterizing Radome Health

Traditionally, radome diagnostics have been done with indoor or outdoor measurement ranges, which are expensive assets to not only build but also maintain. More recently, the US Air Force invested in a new paradigm for radome diagnostics that utilizes cobots to scan microwave probes and create a digital twin of a radome under test. This newer state-of-the-art method utilizes compact, rugged microwave sensors that illuminate a small area of the radome surface with relatively wide bandwidth radiation. This bandwidth has proven effective in determining electrical thickness of 1, 3, and 5-layer radomes for aircraft nosecones that typically employ X-band radars. With the speed and low cost of this microwave scanning method, it can be used more broadly than for just final quality assurance. With its moderate footprint, scanning radome diagnostics can occur in the repair facility itself and employed more often to measure radomes at the beginning and at intervals during the radome refurbishment. This allows radomes to be diagnosed before repair so that if repairs are not viable, valuable time and resources are not wasted on a radome that will end up being condemned anyway. Earlier diagnostic scanning also has the potential for not only verifying layer thickness, but also to identify defects that need repair. However, the additional requirement of identifying defects in radomes is more difficult than determining layer thickness. This drives a need for expanding the sensitivity of the microwave method to fulfill this additional requirement. Improved sensitivity will facilitate detection of more subtle defects. Furthermore, advanced radomes that include band-pass or polarizer layers within the multiple core and shell layers require additional data to diagnose these even more complex structures on advanced aircraft. To this end, the proposed sensor will expand the bandwidth and utility over the current state-of-the-art microwave probes. The planned effort includes design and construction of a two different sensor designs. The effort will manufacture multiple copies of each probe design so that it is manufacturing-ready by the end of the program.