RECCO is a rescue technology used by organised rescue teams as an additional tool to more quickly locate people buried by an avalanche or lost in the outdoors. The system is based on a harmonic radar system and composed of a detector and a passive reflector integrated into outdoor clothing and gears. History The RECCO rescue technology was developed by Magnus Granhed, in response to his personal experience with a fatal avalanche accident in Åre, Sweden, in 1973. Starting in the winter of 1978–1979, Granhed collaborated with Bengt Enander's team at the Department of Electromagnetic Theory, Royal Institute of Technology in Stockholm to develop an avalanche rescue system, using the principle of harmonic radar. Granhed formed RECCO AB in 1983 and created the first functional prototype. In 1987, a woman was localised with the RECCO rescue technology from a helicopter in Lenzerheide, Switzerland, in the first live rescue found using the technology. In 2015, RECCO introduced the RECCO SAR Helicopter detector that expands the technology to finding a missing person in other outdoor environments. The system Based on the harmonic radar system, the RECCO rescue technology consists of two parts: a passive and lightweight reflector and a portable detector. The reflector is worn by the person and directly integrated in the clothing or gears. The detector is used by professional rescue teams on avalanche site, by foot or from a helicopter. The reflector The reflector is a passive transponder, which does not require batteries or activation, consisting of a diode and an antenna. Its dimensions are 13 mm × 51 mm × 1.5 mm and it weighs 4g. The company suggests that two reflectors in different locations are ideal. More than 150 brands integrate RECCO reflectors into their outdoor gear, including ski boots, helmets, hiking shoes, jackets, pants and backpacks. The handheld detector The detector sends out a highly directional radar signal. If the signal hits a reflector it is echoed back to the detector. The returned signal is translated into an audio tone if the detector is pointed in the direction of a reflector. Judging from the audio tone a trained professional rescuer can determine the location of a buried victim. Due to the diode, the returned signal is doubled in frequency - harmonic radar. The R9 detector, released in 2009, weighs 900 grams. During a search and rescue, its signal can locate RECCO reflectors within a range up