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Description of the radar set, tactical-technical characteristics

Figure 1: Long Range Discrimination Radar Equipment Shelter (LES)
(64°18'07.4" N   149°09'43.6" W)

Figure 1: Long Range Discrimination Radar Equipment Shelter (LES)
(64°18'07.4" N   149°09'43.6" W)

frequency: S band
pulse repetition time (PRT):
pulse repetition frequency (PRF):
pulsewidth (τ):
receiving time:
dead time:
peak power:
average power:
instrumented range: 7 000 … 12 000 km
range resolution:
hits per scan:
antenna rotation:


Long Range Discrimination Radar (LRDR) at Clear Space Force Station, Alaska, is operating in the S band multi-mission, multi-face radar designed to provide search, track, and discrimination capability to support the Homeland Defense Capability against missile threats to the homeland and in the Pacific theater. The LRDR is integrated into the missile defense system through the Command and Control, Battle Management and Communications (C²BMC) element. In addition to missile defense, the LRDR supports space domain awareness by monitoring satellites orbiting the earth, detecting, tracking, and identifying active or inactive satellites, spent rocket bodies, and fragmentation debris.

Each of the surfaces housing the active phased array antennas is 60 feet high and 60 feet wide (15.24 × 15.24 meters). Located behind the surface is the scaffolding with ten stacked antenna modules, each approximately 40 feet high and 16 feet wide (12 × 5 meters). Each of these contain almost 288 slots for T(R modules (so-called “subarray suites”, SAS). How many of these SAS are fitted depends on the position of the module in the antenna array. The single antennas provide dual polarization. The T/R modules are manufactured using gallium nitride technology.

Construction of the LRDR in Alaska commenced in September 2017, and it achieved operational readiness by 2022.

The Homeland Defense Radar – Hawaii (HDR-H) is a scaled-down single-face version of the LRDR.

Picture gallery of LRDR

Figure 2: Illustrative model of LRDR created during the planning phase

Figure 3: Single-face version HDR-H