The project will combine for the first time a multi-role lighter-than-air (LTA) unmanned aerial vehicle (UAV) with an ultra-high resolution multi-sensor surveillance payload supporting border surveillance as well as search & rescue applications, and specifically rough terrain detection. The sensor payload will include synthetic aperture radar (SAR), shortwave/longwave infrared (SWIR/LWIR), acoustic cameras for direct target detection, as well as optical and hyperspectral cameras for indirect detection (via vegetation disturbance). The technology concepts will be validated in the field by 4 border police units (Greece, Bulgaria, Romania, Moldova) covering 3 major illegal migration routes into Europe (Eastern Mediterranean, Western Balkan, and Eastern Borders Routes), which represent 58% of all illegal border crossings detected and are also the most used for smuggling of drugs, weapons, and stolen vehicles.