A Study on the Characteristics of Sunglint in LongWave InfraRed Band

Kim, Kyung Ha

doi:2018.21.3.306

J. KIMS Technol > Volume 21(3); 2018 > Article

Research Paper

Journal of the Korea Institute of Military Science and Technology 2018;21(3):306-314.
DOI: https://doi.org/10.9766/KIMST.2018.21.3.306

A Study on the Characteristics of Sunglint in LongWave InfraRed Band

Kyung Ha Kim

The 1st Research and Development Institute, Agency for Defense Development

원적외선 대역의 태양 직사광 해수면 반사신호 특성 연구

김경하

국방과학연구소 제1기술연구본부

Abstract

In maritime environment, it is necessary to understand the characteristics of sunglint since it may degrade the target detection performance of the infrared sensor mounted weapons. In this paper, sunglint in LWIR band is modeled using the slope distribution of the sea surface, and is verified by comparing the radiance of a simulated result with that of the real world. According to the simulation, sunglint is critical when the solar zenith angle is over $60^{circ}$. The peak radiance of sunglint grows as the solar zenith angle increases until it reaches $83^{circ}$ and has a large difference depending on the solar zenith angle when the wind speed is small. Finally, seasonal and temporal characteristics of sunglint effects are analyzed. In summer, sunglint is dominant in the horizon near the solar azimuth right after sunrise and before sunset. However, in winter, the influence of sunglint lasts even during the daytime since the elevation of the sun is much lower than in summer.

Key Words: Sunglint, Maritime, LWIR