What is asos in aviation

All of this is carried out through the use of numerous sensors, computers, and digitalized voice communications. ASOS is broadcasted over discrete VHF frequencies and the voice portion of a local navaid as they are designed to be able to reach out as far as 25 nautical miles horizontally in all directions, and up to 10, feet Above Ground Level AGL.

The ASOS system installation began in , and is the primary surface weather observation system that is used in the United States today. Up to 1, systems are to be installed at airports across the United States. Charter Quote.

Now Hiring! PBJ Logo. These sources derive their information from FAA publications, perhaps most importantly, the Chart Supplement publication as discussed previously. So, which should be used for flight planning? But the communications and weather section are not the only helpful piece of information associated with the Chart Supplement pages. KMCI, being a class B airport, is expected to provide airline crews with extremely accurate weather conditions on the field during low visibility conditions.

So, it is possible to know that RVR reporting can be specified for each portion of the runway, which plays a role in Part and Part operating requirements. Knowing where to look on the official publication is helpful but given the reliance of many pilots on Foreflight or its equivalents, identifying the type of weather source can be more difficult. So, when looking at Foreflight or its equivalents, be mindful of the reported time stamp for the data.

The weather source is also broken out in Foreflight based on source. Accessing the METAR data is often sufficient for much of the preflight planning process, but if it is necessary to access up the minute weather for a departure or arrival airport via a mobile application, the appropriate automated weather station is required. But ATIS data is often generated initially by an automated system then translated by the human operator.

Calling the associated phone number provides up to the minute weather recordings, which can be supremely useful in rapidly changing frontal weather conditions.

If the automated station had a frequency, it would be provided in this location as well. Remember that though Foreflight was the example application in this case, different apps will provide different means of identifying the type of weather report provided, it is good practice to get to know where to look to identify the source of weather as part of normal preflight planning actions for the specific app or data source in use.

The preflight process may also include a simple scan of navigation charts. Fortunately, the type of weather source is identified on both sectional charts and enroute IFR charts.

The availability of weather stations along a route of flight during VFR operations may seem trivial during early student solos where the weather is consistently good, but on long cross-country flights to unfamiliar areas in changing or marginal conditions, quick identification of routes between weather stations can pose significantly better situational awareness.

Similarly, knowing what type of station is available offers clues, in light of the service table above, as to what weather phenomena can be monitored.

Particularly during IFR operations, the ability to identify the type of weather available at an airport can be crucial during diversion scenarios. Diversion to an airport with weather data usually guarantees lower weather minima and where applicable, the availability of monitored weather data is even more helpful. Differentiating between these sources has important implications for approach planning and for commercial operations. Those concepts are beyond the scope of this discussion, but awareness of the resource is helpful.

Weather data and weather stations are largely automated at most small airports, while larger airports will tend to use monitored systems that rely on human intervention.

Depending on the installed sensors, various weather phenomena will be detectable. But winds, temperature, dewpoint, visibility, the altimeter setting, and cloud conditions will universally be available at airports with weather stations and many stations will offer addition information. At non-airport automated stations, the available data may be greatly reduced, but that data is largely outside the scope of aviation planning resources.

To make the best use of what these systems offer to pilots, become familiar with the tools available as mobile applications or as paper charts, and know where to find the pertinent weather source types and frequencies. Allen is a certified flight instructor and lifelong aviation enthusiast.

Climate and meteorological researchers use them every day. There are even a few ASOS stations not located at airports. METAR reports often contain very detailed remarks that are of little use to pilots. For example, ASOS stations often report temperature and dew point to the tenth of a degree and six, twelve, and twenty-four hour precipitation totals. Each sensor that makes up these systems has limitations.

For example, the ceilometer used on ASOS stations cannot detect clouds above 12, feet. There are also many types of precipitation and particulate that they cannot differentiate. Visibility is also sometimes a problem for the sensors. Patchy fog is a problem in that if the obscuration is not directly on top of the sensor, the unit cannot see it.

As a result, runways could be completely fogged in, but the automated observer might report good visibility. News: To better serve our users and the aviation safety community, SKYbrary is transitioning to a new, more flexible platform mid-November , providing users with a better service and easier access to the wealth of safety knowledge it offers. If you wish to access the latest content from the SKYbrary team, please visit and bookmark www.

Automated Weather Observing System AWOS is a fully configurable airport weather system that provides continuous, real time information and reports on airport weather conditions.