Measuring optical turbulence using a laser DIMM in support of characterization of imaging system performance

The MITA (Motion Imagery Task Analyzer) project was conceived by CBP OA (Customs and Border Protection - Office of Acquisition) and executed by JHU/APL (Johns Hopkins University Applied Physics Laboratory) and C5ISR Center NVESD (Command, Control, Computers, Communications, Cyber, Intelligence, Surveillance, and Reconnaissance Center Night Vision and Electronic Sensors Directorate). The intent is to develop an efficient methodology to characterize imaging system performance objectively, in a field setting, using a target resolution board and simultaneously measuring the turbulence along the camera line of sight. The initial design, development, and testing of MITA was previously reported (Hixson et al) and an additional set of field measurements and subsequent modeling results are reported here. The initial MITA design uses a transmitter at the imaging system location and a DIMM receiver in the field with the resolution target to measure the path turbulence, so a strong understanding of the path-averaged turbulence reciprocity is needed for proper implementation of the MITA system. To this end, a test series was conducted to explore the reciprocity of path averaged optical turbulence measurements using two scintillometers and the laser DIMM receiver in both bi-static and mono-static configurations. Finally, the path averaged measurements are compared with modeled turbulence along the path based off of the available meteorological data.