Abstract <p>The article presents a device for detecting and localizing humans over long distances in the thermal infrared region, featuring an ultra-large coverage area. The device consists of eight conical horn elements and corresponding thermal sensors. The horns are positioned in such a way that the angle of view of adjacent elements partially overlaps. Theoretical considerations enabled the identification of a suitable solution for the angles between adjacent horns, resulting in an almost uniformly distributed angular detection profile with a total angle of view of 110°. This enabled the optimal design of the horn element arrangement in the device to effectively detect and localize humans, with a detection range of 30 m and a horizontal coverage area of 863.9 m². The summed level of thermal signals from two adjacent sensors allows estimation of the distance to a human, and their ratio determines the observation angle.</p>