Radartutorial .eu SRE-LL
Figure 1: Former SRE-LL site near Bremen
(© 1998 DFS Deutsche Flugsicherung, H.-J. Koch)
Figure 1: Former SRE-LL site near Bremen
(© 1998 DFS Deutsche Flugsicherung, H.-J. Koch)
The SRE-LL radar (Surveillance Radar Equipment, twin-L-Band) was developed by AEG Telefunken since 1969, the prototype was installed near Bremen (see Figure). Until 1974 five more series were delivered for a gapless radar coverage in the former western Germany. SRE-LL radars remained operational until the mid-90'ies.
The use of two antennas in back-toback configuration (the so called “Janus-Design”) gave a better information renewal time for a given revolution rate. The reflector dimensions were 14.5 • 9 m. Both antenna halves generate a Cosecant squared antenna pattern. The lower edge of the pattern was increased by a Pencil-Beam blanked in the inner range around the radar. The total weight of the rotating parts of the antenna was 60 tons.
| Specifications | |
|---|---|
| frequency: | 1250 - 1350 megahertzes |
| pulse repetition time (PRT): | 2.5 milliseconds |
| pulse repetition frequency (PRF): | 400 hertzes (staggered) |
| pulsewidth (PW): | 2.5 microseconds |
| receive time: | |
| dead time: | |
| peak power: | 5 megawatts |
| average power: | 9 kilowatts |
| displayed range: | 200 nautical miles (370 km) |
| range resolution: | < 400 m |
| beamwidth: | 1° |
| hits per scan: | |
| antenna rotation: | 2 - 7.5 rpm |