Medium Intensity Airport Weather System (MIAWS)

Operational experience with Integrated Terminal Weather Systems (ITWS) and ASR-9 Weather System Processor (WSP) demonstration systems and, recent accidents have demonstrated the need to provide timely accurate information on the location and movement of storms to ATC controllers, pilots, and airline dispatch.

At medium-intensity airports, generally airports with too few flight operations to justify the presence of Doppler radar systems like the Terminal Doppler Weather Radar (TDWR) or the Weather System Processor (WSP), terminal air traffic surveillance is currently provided with the Airport Surveillance Radar-7 (ASR) and ASR-8 radar systems. The ASR-7 and ASR-8 are aging radar systems that are obsolete, not logistically supported, do not provide digital inputs to new terminal automation systems, and do not provide a calibrated precipitation intensity product nor any storm motion information.

The FAA and the Department of Defense (DOD) have embarked on a joint venture to acquire 165 ASR-11 digital surveillance systems to replace the aging ASR-7 and ASR-8 systems. An ASR-11, with a calibrated weather channel, provides precipitation intensity estimates in the NWS 6-level format. However, until the ASR-11 is deployed, airports using ASR-7 and ASR-8 systems need an alternative source of information on storm location and movement.

The Medium-Intensity Airport Weather System (MIAWS) program is intended to address the terminal weather information deficiencies that have been identified in the analysis of a recent jet aircraft crash. MIAWS-generated products would displayed to tower and Terminal Radar Approach Control (TRACON) supervisors and, delivered to aircraft cockpits and airline dispatchers in order to assist pilots during landings,

Initially, the MIAWS will provide a real time display of storm positions and motion based on Next Generation Weather Radar (NEXRAD) product data using a product generation and display system derived from the WSP. A demonstration system will be installed and demonstrated at experimental sites in Memphis, TN and Jackson, MS in the year 2000 and a third site (not yet determined) in the year 2001. This demonstration system will be used to assess technical and operational issues such as compensation for the relatively slow updates of the NEXRAD products and AP ground clutter. Airline dispatch access for Jackson and the third site would be provided initially via the Lincoln Web site in 2000 and 2001. When agreement is reached on an airline access mechanism for the Integrated Terminal Weather System (ITWS) and WSP, this would be retrofitted to the MIAWS. A Terminal Weather Information for Pilots (TWIP) cockpit data link capability would be implemented and demonstrated in the year 2002.

When the ASR-11 becomes available at MIAWS locations, the MIAWS processor would ingest and display precipitation and storm movement products derived from the ASR-11 (i.e., NEXRAD would be an interim source of precipitation information).