OSM-IR – A tool for the simulation of maritime scenarios in the infrared

Computer simulation of sea surfaces in the IR

OSM-IR (Ocean Surface Modeling – IR) is a computer program with a graphical user interface for the radiometric calculation (IR band SWIR, MWIR and LWIR) and visualization of maritime scenarios consisting of a dynamic sea surface and a static, cloudless sky layer. Possible applications are the determination of hazard areas and the risk assessment of laser light reflection at the dynamic sea surface. The most important input parameters for OSM-IR are the meteorological parameters wind speed, wind direction, or fetch, and the sensor parameters sensor height, sensor declination angle, and field of view (FOV). External radiation sources, such as the sun, or a laser source can also be integrated into OSM-IR to calculate the radiance of the sun (sunglint) and total reflected laser power, respectively. The bidirectional reflectance distribution function (BRDF) of the sea surface is considered for both light sources.

Functionalities of OSM-IR

• Fast calculation of a maritime scenario (sea surface and sky) in the infrared spectral band
• Detailed simulation of the reflected power (radiance) of a laser beam (from sunlight) considering the BRDF of the sea surface
• Simulation of whitecaps, choppy waves, and polarization effects of the sea surface
• Visualization of the simulation results

Scopes

• Determining the amount and direction of reflected laser energy in a maritime scenario
• Model validation with field trial data: validation of the BRDF by measurements of the laser power reflected at the water surface for different meteorological and geometric configuration of the laser source and the receiver
• Development of laser safety concepts for risk assessment when considering laser light reflection in a maritime scenario