Automated Surface Observing System. ASOS User's Guide

The ASOS Users Guide provides a fundamental description and explanation of ASOS and its impact upon users of the Aviation Routine Weather Report METAR and other ASOS data. This guide is therefore designed to speak to a variety of interests inside and outside the federal meteorological community. The guide is written for those with more than a rudimentary understanding of the manual surface observation program. Using the manual observation as context, the ASOS Users Guide describes the basic ASOS functions of data ingest, data processing and data distribution. Descriptions are provided, element by element, of the sensors and algorithms that ASOS employs. The guide also discusses the unique strengths and limitations of each ASOS data element. Among the basic strengths of the ASOS observation is its capability to measure critical aviation weather parameters, such as sky condition and visibility, at specific locations where they are needed most-the touchdown zones. ASOS data are updated once each minute and transmitted directly to forecasters, air traffic controllers and pilots. ASOS is capable of performing all the basic observing functions and operating in either attended or unattended mode, enabling observing personnel to focus on other demanding duties. ASOS data is accessible through a variety of media never before available from a surface observing site. Local, on-site video screen displays are available on the Operator Interface Device OlD and the Video Display Unit VDU. Additional video monitor hook-ups can be made available to airlines and other external users at the airport. Authorized remote users can acquire a wide variety of ASOS data through the a remote user dial-in port. Computer-generated voice message are provided by ASOS for local FAA radio broadcast to pilots and are made available for general aviation use through a dial-in telephone number for each location.