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RRP-117 “Seek Igloo”

RRP - 117
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Figure 1: RRP-117 antenna
© Lockheed Martin

The air-defense radar RRP-117 (Remote Radar Post) is a completely D-Band radar system in solid state technology. It consists of a primary radar, a secondary radar and a subsystem for simulation. The RRP-117 provides 3D- targetinformations in real time over the whole range of detection correlated wit the informations of the secondary radar. It uses a phased array antenna turning within 6 rpm and an electronically steared beam in elevation.

In condition of the using of solid state transmitter modules the radar works with the pulse compression to reach a better range resolution nevertheless the relatively long pulsewidth.

Antennae pattern of a 3D-radar
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Figure 2: Antennae pattern of a 3D-radar

But that is only half the truth: during the transmitting time the antenna is busy and the receiver cannot work! If the pulse width of the transmitter is e.g. 800 microseconds then the receiver can work from 800 µs ·150 m= 120 km. The possible pulse width is limited therefore and the most radar sets use alternating a shorter pulse as the so called “short range mode”. The peak power is the same as by the long range mode. The shorter pulse make the energy balance weaker and so the radar set reaches a lower maximum range as by the long range mode.

AN/TPS-117
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Figure 3: Animation AN/TPS-59

Lockheed Martin's family of ground based radar systems includes the AN/TPS-117, a mobile variant of the 117-radar and the AN/TPS-59 of the iHAWK missile system.

Sources: magazine “Luftwaffe” (ISSN 0015-3699) 39/12 (December 1998) page 2
Leaflet of the Lockheed Martin Company: LM_(3).pdf (1002 kByte)

Figure 4: Maintenance-shelter with the control processing group

Sichtgeräte- Shelter Sekundärradar Schaltschrank Sichtgerät für Wartungszwecke Sichtgerät zur Bedienung der Radarsoftware GPS-Empfänger als Zeitbasis Fernmeldekonsole
Figure 4: Maintenance-shelter with the control processing group

Description of the radar set, tactical-technical characteristics
Описание; Основные тактико-технические характеристики (Базы данных)

Specifications
frequency: 1215 - 1400 MHz
pulse repetition time (PRT): 0,9 - 4 ms
pulse repetition frequency (PRF): 250 / 1100 Hz
pulsewidth (τ): 100 / 800 µs
receive time: 0,6 / 3 ms
dead time: ca 200 µs
peak power: 20 kW
average power:  
displayed range: bis 463 km
range resolution:  
beamwidth: β:3,4°, ε:2,7°
hits per scan: 1 ... 3
antenna rotation: 10 s