Multifunction Phased Array Radar

Multifunction Phased Array Radar

MPAR being installed in 2003.
Country of origin	USA
Introduced	2003
No. built	1
Type	Weather radar
Frequency	2,700 MHz (S band)
PRF	918 Hz
Beamwidth	0.7°
Pulsewidth	Adjustable to 2.5 μs
RPM	Manually steered
Altitude	360 m (1,180 ft)
Diameter	3.7 m (12 ft)
Azimuth	Manually steered
Elevation	up to 60º
Power	750 kW

Multifunction Phased Array Radar is an experimental radar system that is derived in Phased Array technology. Conceptually, MPAR can scan at angles as high as 60 degrees in elevation, and simultaneously track meteorological phenomena, biological flyers, non-cooperative aircraft, and air traffic. Throughout the next decade, NOAA plans to gradually decommission their TDWR and NEXRAD systems in favor of several hundred dual-pol MPARs. As of 2017, there is one MPAR in operation within the mainland United States - a decommissioned AN/SPY-1 radar donated to NOAA in 2003 by the U.S. Navy.

May 31, 2013 Oklahoma Phased Array Radar Reflectivity

History

The radar, a U.S. Navy AN/SPY-1, first saw service beginning in 1973, and was installed on the USS Norton Sound 10 years later. During its engagement, it was noticed that the false-alarm rate was high due to the radar detecting swarms of insects and nearby mountainous terrain. Although problematic for mitigation of threats nearby, this proved vital for Phased Array as a candidate in the meteorological spectrum. As time progressed and different variations of the AN/SPY family arose through the 90s, in 2003 the U.S. Navy donated one AN/SPY-1A antenna to NOAA for meteorological research. Once donated, NOAA built a small tower and pedestal outside of their Radar Operations Center in Norman, Oklahoma to house the antenna and its components.

Deployment and uses

From 2003 to 2016, the MPAR located in Norman helped lead to much faster volume scans, and more complete insights to supercellular structure. Due to the time resolution ranging from 30 to 60 seconds and the one-sector scanning solution MPAR practices, lead time also increased as much as 8 minutes from the already existing 13 minutes. One problem is the polarization - that is, the polar orientation of the beam within the Phased Array. In recent years, dual-polarization in the horizontal and vertical poles have been put to use in the NEXRAD system, which operates with axial-fed parabolic antennas. However, since the MPAR antenna is not in this configuration, dual-polarization is still an experimental concept and has yet to be tested on a large scale. MIT is heading the project of dual-pol MPAR, and a prototype is likely to be installed in Norman within the next 3 years on a non-operational basis. Besides meteorological observation, the FAA also is likely to phase out their current system of ASR/TDWRs in favor of MPAR. While mainly for meteorological uses for local NWS WFOs, MPAR is conceptually built an air-monitoring radar. This being so, it can constantly scan in specific sectors for aircraft, biological clutter, and wind shear at most elevations.