Problem
As the flight profiles for hypersonic weapons expands to ever-higher velocities and ever-lower altitudes, critical technologies are needed to ensure the successful performance of our intercepting airframe, seeker, and seeker window. Aero-optical effects can be extremely severe from blinding the seeker to even causing catastrophic failure of the window.
Solution
Polaris is developing a novel suite of instruments to characterize these effects at heretofore impossible ranges and accuracies for a variety of applications ranging from Ground Test Facilities (GTF) to advanced tactical in situ applications.
Hypersonic aero-optics is the study of the effect of induced compressible turbulence on the performance of an optical seeker.
Ground Test Facilities
Current GTFs are instrumented with advanced sensors to support this investigation, but a set of aero-optical instruments require sizable physical space, are unique to each facility, and require highly trained engineers to operate. Testing at more than one GTF is not uncommon, and some facilities do not have the physical space to accommodate traditional aero-optical instrumentation. To address these needs and more, Polaris is developing an Aero-Optics Kit (AOK).
Aero-Optics Kit
The AOK instrument suite will maximize the aero-optical data captured from a single test run, reduce costs, minimize the number of runs necessary to complete the characterization, and provide ubiquitous capability. The AOK will offer new insights into time-resolved flow fields and is suitable for high-Mach numbers and enthalpies. It will measure 3 different aero-optical effects: basic image performance, window effects, and flow effects.
The AOK is being designed to provide real-time, onboard measurements mounted inside the test article of a cooled or uncooled seeker window. Initially the system will fit into a common Advanced Interceptor Technology (AIT) forebody test fixture for use in hypersonic test facilities. The instrument suite minimizes, if not eliminates, the need for specialized test setups and tunnel modifications. The AOK promotes the ubiquity of aero-optic test capabilities from one GTF to the next.
We are now incorporating modeling and simulation tools to predict the heat induced deformation of the window to the transmitted wavefront. We are also being supported in an effort to validate models for aero-thermal modeling. As part of this, we are providing subject matter expert advice for the impact on testing of aero-optic seeker performance.
