TECHNOLOGY AREA(S): WEAPONS
OBJECTIVE: Develop a 3D imaging approach that meets the spatial and temporal requirements needed for tracking and aim-point maintenance in the presence of target-pose changes for directed-energy (DE) missions.
DESCRIPTION:Target-pose changes tend to be the “Achilles’ heel” to modern tracking and aim-point maintenance solutions for realistic DE missions.Provided well-characterized targets, there are approaches that perform well (e.g., centroid and correlation tracking ); however, for realistic DE missions, tracking and aim-point maintenance techniques must function with uncharacterized targets that inevitably change pose.Such engineering constraints necessitate the development of a 3D imaging approach that can characterize targets (through target-depth information ) and perform tracking and aim-point maintenance functions in the presence of target-pose changes.A recent dissertation effort, for instance, developed a 3D imaging approach  using spatial heterodyne .This STTR topic looks to develop a 3D imaging approach which meets the spatial and temporal requirements needed for integration into DE systems.For realistic DE missions, the associated laser-target interaction does not provide a mirror-like reflection and in the presence of distributed-volume aberrations, results in speckle and scintillation, in addition to anisoplanatism, at the receiver.The identified approach must also be robust against low signal-to-noise ratios; size, weight, and power constraints; and latency in the tracking loop.The end goal of this STTR topic is to develop (Phase I and II) and demonstrate (Phase III) a 3D imaging approach that can characterize targets and perform tracking and aim-point maintenance functions in the presence of target-pose changes for realistic DE missions.As such, a Phase I effort shall develop a 3D imaging approach via detailed theoretical and numerical studies that verify wave-optics calculations for a variety of ranges and resolutions.A Phase II effort shall then develop experiments that verify the wave-optics calculations.For this purpose, facilities at AFRL could provide the scaled-laboratory environment needed to explore a variety of ranges and resolutions.A Phase III effort could then demonstrate 3D imaging at distances greater than 1 km in a field environment with moving targets.Such testing shall ensure commercialization of the developed approach.
PHASE I: To achieve the identified Phase II objectives, a Phase I effort shall focus on the following deliverables.• Performing wave-optics calculations for a variety of ranges and resolutions.These calculations shall identify scalability and include the relationship between the aperture, the distributed-volume aberrations, and the 3D targets of interest.This step shall ensure that the developed approach is ready for a Phase II effort.
PHASE II: To achieve the identified Phase III objectives, a Phase II effort shall focus on the following deliverables.• Performing scaled-laboratory experiments (potentially at AFRL) in order to verify the wave-optics calculations performed in a Phase I effort.This step shall ensure that the developed approach is ready for a Phase III effort.
PHASE III: Military application: Demonstrating the developed approach in a field environment at distances greater than 1 km with moving targets.This step shall ensure that the developed approach is ready for realistic DE missions.Commercial Application: The successfully demonstrated 3D imaging approach shall translate into a high-fidelity solution that is available to the DoD.
1.P. Merritt and M. Spencer, Beam Control for Laser Systems 2nd Edition, Directed Energy Professional Society, Albuquerque, NM (2012).;
2.R. Ng, M. Levoy, M. Bredif, G. Duval, M. Horowitz, and P. Hanrahan, “Light Field Photography with a Hand-held Plenoptic Camera,” Stanford Tech Report CTSR 2005-02, 1-11 (2005).;
3.J. W. Stafford, B. D. Duncan, and D. J. Rabb, “Phase gradient algorithm method for three-dimensional holographic ladar imaging,” App. Opt. 55(17), 4611-4620 (2016).;
4.M. F. Spencer, “Spatial Heterodyne,” Encyclopedia of Modern Optics II Volume 4, 369-400 (2018).
KEYWORDS:3D imaging, tracking, aim-point maintenance, beam control, adaptive optics
CONTACT(S):Dr. JonathanStohs AFRL/RDLT 5058463769 email@example.com