Concealment, Detection, Recognition, and Identification of Target Signature on Water Background under Natural Illumination

Natural illumination is a common attribute and uncontrollable intimidation for concealment, detection, recognition, and identification (CDRI) of defence surveillance. Every research outcome of camouflage engineering needs to conduct field experimentation under natural illumination. CDRI versus natural illumination necessitates to consider for every combat location such as woodland, marine, desertland, stoneland, snowland, sky and iceland. The intensity of natural illumination and surveillance technique determine CDRI due to irrepressible illumination angle and intensity among sunlight, object-background (OB) environment and detector in ultraviolet, visible, and infrared spectrum.  Camouflage field assessment of real OB environments, different weather conditions, season and its variation in natural illumination is also cost involvement and achievement headache for continuous improvement of research. Natural illumination versus CDRI has been investigated in visible range (400-700 nm) using different universal conditions of OB environment in winter season such as foggy morning light (FML), morning sun light (MSL), noon sun light (NSL), evening sun light (ESL), dusk evening light (DEL). A simulation of CDRI of marine target signature was experimented by using “animal object (Anas Platyrhynchos)” as target signature. “Water background in water reservoir” was selected for controlled features of background environment as alternative of marine zone. Natural illumination of CDRI has been methodically explained in terms of Lab (L*, a*, b*) color intensity, key factors of water background and its surrounding in OB environment. The partial protection factors of target signature against marine surveillance were signified based on key rudiments of water background environment such as illumination of sun-position/sunlight-angle, weather condition in winter season, wind speed, target detection angle, shadow, wave of water surface, the chromatic intensity of OB and its surrounding background. The illumination of FML-MSL-NSL-ESL-DEL was indicated as CDRI factors in OB environment. MSL-NSL was remarked as predominant effect of target concealment.  The experimental concept and procedure can be implemented for design and assessment of marine camouflage objects in different areas of camouflage engineering in terms of natural illumination against water background. The investigation proposed a model named CDRI for target OB in natural illumination.