Infrared Polarimetric Sensing of Oil on Water

AbstractInfrared polarimetry for surface spill detection is an emerging sensing modality shown to significantly enhance contrast in situations where conventional thermal imaging cannot detect a spill. Imaging of the polarization signatures of oil and water in a scene can lead to enhanced understanding, particularly when the materials in a scene are at thermal equilibrium. Testing at Ohmsett has shown good performance with multiple types of crude oil, diesel fuel, and kerosene in several different viewing geometries. Over the course of two separate tests at Ohmsett, recoverable oil was detected during day and night, in calm water and in waves, when puddled on sand and rocks, with and without dispersant, on the surface after subsurface releases, and for fresh, aged, and emulsified oil. In-situ testing has confirmed these capabilities. This new remote sensing capability offers the promise of automated detection of oil spills and leaks for routine monitoring and accident response with the added benefit of continued monitoring at night. The camera has a small form factor that is compatible with all types of platforms including small drones. Polaris Sensor Technologies has tested this technology extensively at the Ohmsett Test Facility with several opportunistic tests in the Gulf of Mexico and near Santa Barbara, CA, with an emphasis on finding the limits of performance. In this paper, we describe the instrumentation and the test results in both controlled and uncontrolled conditions.