Are AWOS and ASOS identical? No. Although similar, there are several versions of AWOS with different arrays of sensors. The report format is similar and is controlled by international standards. Reports differ by the type of sensors on the system (system configuration). A01 indicates an automated station without a precipitation identification sensor. A02 indicates an automated station with a precipitation identification sensor. An AWOS I processes and outputs temperature, dewpoint, barometric pressure, density altitude, wind speed, wind direction, and gusts. An AWOS II adds visibility to the AWOS I parameters. An AWOS III provides cloud height/condition in addition to the above parameters. An AWOSIII-P adds a precipitation type identification sensor. An ASOS includes the parameters of an AWOS III plus a freezing rain sensor and thunderstorm reporting. AWOS I: Wind Speed, Wind Gust, Wind Direction, Variable Wind Direction, Temperature, Dew Point, Altimeter Setting, Density Altitude AWOS II: Same as AWOS I + Visibility, and Variable Visibility AWOS III: Same as AWOS II + Sky Condition, Cloud Height and Type AWOS III-P: Same as AWOS III + Present Weather, Precipitation Identification AWOS III-T: Same as AWOS III + Thunderstorm and Lightning Detection AWOS III-P-T: Same as AWOS III + Present Weather and Lightning Detection ASOS Automated Weather Observing System The Automated Weather Observing System (AWOS) is a suite of sensors, which measure, collect and disseminate weather data to help meteorologists, pilots and flight dispatchers prepare and monitor weather forecasts, plan flight routes, and provide necessary information for correct takeoffs and landings. AWOSs provide a minute-to-minute update that is usually provided to pilots by a VHF radio on a frequency between 118 and 136 MHz. AWOSs are categorized as either Federal or NonFederal. Federal AWOSs were purchased and are currently maintained by the FAA. NonFederal AWOSs are purchased and maintainted by state, local, and private organizations. The sensors measure weather parameters such as wind speed and direction, temperature and dew point, visibility, cloud heights and types, precipitation, and barometric pressure. The AWOS does not predict weather, but many send current information to weather offices where forecasts are produced using this information along with computer model outputs, satellite photos and radar images, to name a few. Every hour on the hour, the AWOS data is made available to off-site users by those AWOSs on Service A (long line telephone communication) or satellite uplink. The aviation community, which is one of the largest users of environmental data, is the major user of the AWOS information. Information broadcast by an AWOS III Airport identifier Zulu time Sky Conditions Visibility Wind speed Wind Direction Temperature Dew Point Altimeter Setting Remarks Density Altitude Wind Gusts Automated Surface Observing System The Automated Surface Observing System (ASOS) is an automated observing system being sponsored by the Federal Aviation Administration, National Weather Service (NWS) and the Department of Defense (DOD). ASOS provides weather observations which include: temperature, dew point, wind, altimeter setting, visibility, sky condition, and precipitation. 569 FAA-sponsored and 313 NWS-sponsored ASOSs are installed at airports throughout the country. Automated observing systems are designed to provide the pilot, and other users, airport weather observations "When they need it and where they need it." The observing systems work nonstop, updating observations every minute, 24 hours a day, every day of the year. By providing information on the atmosphere, at increasing locations, these systems are designed to improve the safety and efficiency of aviation operations as well as being the key to improving forecasts and warnings. A basic strength of automated observing systems is that critical aviation weather parameters are measured where they are needed most; i.e., the runway touchdown zone on the airport. The automated observing system routinely and automatically provides computer-generated voice directly to aircraft in the vicinity of airports, using FAA VHF ground-to-air radio or apended to the ATIS broadcast. In addition, the same information is available through a dial-in telephone and most of the data is also provided on the national weather data network.