A long range optical sensor and system for detecting the flame of forest fires or other fires while rejecting false alarms due to solar radiation is described. The sensor utilizes a collector optic that collects energy from a wide field of view and concentrates the energy onto a detector. The collector may be a non-imaging collector and may match to a non-planar sensor. In one embodiment the sensor may be arrayed to achieve larger area coverage. In another, the sensor system may be scanned to increase the encompassed viewing area. Larger areas may be covered by RF radio links or networks interconnecting multiple arrayed sensor modules. UVC reflective coatings may include enhanced aluminum with silicon dioxide, silicon monoxide, or magnesium fluoride, or high phosphorous nickel phosphorous. In one embodiment a UVC sensitive Geiger Mueller tube may be coupled to a non-imaging spherical reflective collector. A catadioptric UVC/infra-red flame sensor is disclosed. Refractive or reflective designs are considered.