Juneau Airport Uses WAM System for Air Traffic Control

The Juneau International Airport has deployed the Wide Area Multilateration (WAM) system of the Sensis Corporation and in this process has obtained the Federal Aviation Adminstration (FDA)’s Inertial Operating Capability (IOC).

The airport uses the system for providing high availability, very accurate helicopter and aircraft surveillance controllers for the Anchorage Air Route Traffic Control Center (ARTCC), thereby empowering ATC-based traffic advisory and radar services for pilots who operate in the Juneau airspace. The system offers surveillance data to the Traffic Information Services-Broadcast (TIS-B). The FAA Surveillance and Broadcast Services (SBS) ADS-B Program is launching this TIS-B in Southeast Alaska.

Current long range radar system is not effective under Mean Sea Level (MSL) of 10,000 feet due to the limited infrastructure and the mountainous terrain, while it is financially not possible to install more gap filler radar systems. For improving the flight safety at this airport a WAN system has been requested by the FAA for covering the airspace about 20 miles north, 10 miles south and 40 miles west of the airport. As per the FAA’s direction, Sensis has installed a WAM system in the mountainous region around the airport for provision of controllers with enhanced situational awareness for all the flights in the region ranging from 20,000 feet MSL to 200 feet above ground level (AGL) around the airspace. A range of communication systems enable communications between the remote sensors and the target processor. These systems include Juneau Police microwave links, microwave links of the FAA and digital data system circuits that are leased.

Multiple non-rotating, low-maintenance sensors are used by the WAM for triangulation of aircraft positions based on signals from the transponder for providing accurate position and identification information on an aircraft to the air traffic controllers, irrespective of weather conditions.  With greater positional accuracy and higher update rate than customary radar, the WAM offers effective surveillance ensuring enhanced efficiency, capacity and safety of airports and airspace. This system provides lower lifecycle cost and a less complex solution by utilizing the least quantity of sensors. Every additional sensor installed by Sensis is capable of supporting the Automatic Dependent Surveillance – Broadcast (ADS-B).

Sensis Air Traffic Systems’ General Manager and Vice President, John Jarrell, informed that the WAM system had to overcome weather and terrain challenges in the Juneau airport and comply with the strict performance requirements stipulated by the FAA for separation services.

Sensis is also offering solutions for various WAM surveillance applications worldwide, such as en route surveillance (North Sea, U.K. and Tasmania, Australia) precision runway monitoring (Sydney Airport, Australia) and terminal area surveillance (King Abdulaziz International Airport, Saudi Arabia).