Weather Observations
The ASOS system was developed in the late 1980s to relieve the expense of maintaining human observers at hundreds of sites, improve consistency of observations, and bring high-quality observations to rural and remote airports. Much like NEXRAD it was a joint product of the FAA, NWS, and DoD, and was fielded at 1000 US airports between 1991 and 2004. Its main components are temperature, dewpoint, and wind sensors, along with new technology like sky condition, present weather, and visibility sensors.