CARSR

 Long range radar Set - A set of long range radar components built by Raytheon to upgrade FAA legacy radar sets to a common set of transmitters and receivers. Only the antenna components were retained, the rotary joint, diplexer/Polarizer and the physical antenna and drive mechanism.

CARSR Radar
The Common Air Route Surveillance Radar (CARSR) is a new long-range L-band radar with a range of 200 nm. CARSR is the result of a Service Life Extension Program (SLEP) that replaced the vintage ARSR-1, ARSR-2, ARSR-3, FPS-20A, FPS-66A, FPS-67A/B and FPS-93A components with modern components. The klystron transmitters were replaced with a common solid-state transmitter. Even though the receiver and signal processors were upgraded by Northrop Grumman in the early 1990s, they were replaced with more modern software-driven components.

The new transmitter components transmit a fan beam as the antenna rotates at five rpm. The SLEP design uses advanced MTD (Moving Target Detector) techniques with enhanced sensitivity and detectability of weak targets in the presence of clutter to replace legacy moving target processing. The CARSR Radar is interfaced with either a Mode S or an ATCBI-6 secondary surveillance radar (Beacon) and also reports the weather in NWS six-level format. The CARSR SLEP upgrade also replaces the legacy Common Digitizer-2 (CD-2) processors and associated radar data interfaces.

Under a $260 million 2006 contract for the Long Range Radar Service Life Extension Program, Raytheon was selected by the FAA to replace 40-year-old legacy systems at 82 sites in the United States and Puerto Rico. The first production system was deployed to the Coopersville FAA Radar Site in Michigan and two systems were operational at the FAA Academy in Oklahoma City for training and engineering support.

The CARSR program is now complete and there are 80 operational CARSRs installed across the U.S. and Puerto Rico. In addition, three non-operational CARSRs are located at the FAA’s Aeronautical Support Center in Oklahoma City. The expected life of the upgraded radars is between 15-20 years.

See Also:
 * FAA En-Route Radar Site Maintenance Training
 * US Radar Sets

Sources:
 * Wang, Brookner, Cornell Gerecke and Farr, Modernization of Enroute Air Surveillance Radar, IEEE Transactions on Aerospace and Electronic Systems, Vol. 48, No. 1, January 2012, pages 103-115.
 * Raytheon Receives FAA In-Service Milestone Decision To Upgrade Long Range Radars, Raytheon Company Press Release, 28 Sep 2011, Marlborough, Massachusetts. Link

Links:
 * Radomes - Radar Equipment
 * Wikipedia - Air Route Surveillance Radar