Slant Path Optical Turbulence and Atmospheric Characterization

The US Army requires a multi-technique slant path optical turbulence and atmospheric characterization field data collection system that can be part of an Unmanned Aircraft System (UAS) payload. This system would support measurement of optical turbulence and atmospheric characterization through imaging and meteorological sensor suite allowing (i) single-ended, (ii) simultaneous and multiple line-of-sights for horizontal and slant path measurements in addition to (iii) flexible positioning of the measurement site (via control of UAS). This is a significant improvement over existing large ground- or tower-based scintillation and transmission measurement systems that are not designed for slant path measurements, measure single line of sight, and require extended hardware calibration. Department of Defense (DOD) is spending billions of dollars developing optical laser weapon and targeting systems for the warfighter as well as infrared sensor/imaging systems that can provide enhanced imaging in Degraded Visual Environments (DVE) on both land and air platforms. US Air Force (USAF) and US Army programs to be fielded within the next 5-15 years will require slant path optical atmospheric transmission and atmospheric turbulence truth data. The ability to test and characterize atmospheric turbulence and atmospheric transmission properties will be critical, affecting the performance of advanced laser systems and aircraft imaging systems. To address need in the SBIR A19-024 Phase II program, Alphacore will build the slant path atmospheric characterization and optical turbulence measurement system concept investigated in Phase I period into a fieldable prototype system called OCULAR (OptiCal tUrbuLence meAsuRement) system. OCULAR is a UAV mountable field data collection system for both horizontal and slant path measurements consisting of high-frame rate visible (VIS) and Long-Wave Infrared (LWIR) imaging cameras, laser range finder, and on-board mini wind and weather sensors. The system also has a Ground Control Station consisting of a complete meteorological station. The UAS payload together with ground station will provide integrated path and nodal measurements and compose a complete atmospheric characterization solution. In Phase II Alphacore will compare reference scintillometer measurements against Alphacore’s OCULAR system. These field tests will be performed for (i) both day and night, (ii) horizontal path, (iii) slant-path (using a tower) for at least 2 different environmental conditions. In addition, product usefulness will also be verified by comparisons to truth data and simulation results from multiple reliable sources based on measured atmospheric sounding profiles. OCULAR will be integrated into an easy to use Graphical User Interface (GUI) that can be adapted for use at government test range facilities. This software improves upon the software developed by Alphacore during Phase I.