While the Navy’s aircraft carrier battle groups complete their missions at sea in support of the nation’s security, the carrier and its enclave are protected by E-2 Hawkeye aircraft that patrol the sky and ocean’s surface to identify potential enemy threats.

A primary tool of the Hawkeye’s defensive posture is the rotodome radar system, maintained by Fleet Readiness Center Southwest (FRCSW).

The 24-foot round component “piggybacks” on the E-2 airframe and serves as an airborne early warning system (AEWS) to the battle group.

Weighing approximately 2,500 pounds and with more than 33,000 parts, the rotodome houses two primary components: UHF radar antenna array and the Identification Friend or Foe (IFF) antenna system.

The radar has the capability to scan from the horizon to the stratosphere, while its IFF signal scans and interrogates other aircraft. When the aircraft receives the signal, it answers back via a transponder which returns identifying information.

In addition to the Navy, FRCSW also provides rotodome maintenance to the U.S. Department of Homeland Security (DHS) and its Customs and Border Protection Agency, and foreign militaries.

In DHS use, the rotodome is fixed to the P-3 Orion, a patrol and anti-submarine warfare aircraft, and used in reconnaissance and law enforcement missions.

Overhaul of a rotodome averages between six to nine months and is completed in three phases: renovation to the radar systems gear box and mounting shaft, and the dome and its internal components are tested for proper operation and repaired as required. The component is also painted before delivery to the fleet.

To increase efficiency and safety in testing rotodome radar antenna, FRCSW built the Navy’s first Indoor Spherical Near-Field Antenna Measurement System (SNAMS) about seven years ago.

Previous testing took about one week and required an area of more than one acre due to the hazards of testing high-power radar. The SNAMS testing area is approximately 40-feet by 40-feet, harmless to the operator, and testing is complete in only four hours.

SNAMS is used with an anechoic chamber that is equipped with a fire detection system. The chamber is lined with broadband pyramidal microwave absorbers and provides a controlled environment to accurately measure antenna patterns and verify radar performance.

SNAMS is not limited to rotodome use. It is capable of testing any radar antenna up to 24-feet in diameter and weighing up to 12,000 pounds, over a frequency range of 400 megahertz to 18.0 gigahertz.

FRCSW overhauls and repairs about 10 rotodomes per year.