From September 1997 to September 1998 a VHF-radar was operating at Kühlungsborn (54.1°N; 11.8°E) for the investigation of the dynamics and structure of the tropo-, strato-, and mesosphere. The transmitting and receiving technique was transported to Andenes/Norway (69.01°N; 16.03°E) where it was operated continuously and unattended as the Alomar Wind Radar, ALWIN (Latteck et al, 1999) from October 1998 until September 2008.
During summer 1999 a new VHF-radar (OSWIN) was installed at Kühlungsborn using the existing antenna field and new transmitting and receiving units.OSWIN is a monostatic radar using a phased array antenna consisting of 144 four-element-Yagi antennas grouped in quadratic subsystems of four antennas each and arranged in a 6x6 matrix. The antenna beam can be tilted to three off-zenith angles (7°, 13°, 20°) in the four directions North, South, East, and West by a phase delayed feeding of the six antenna rows or columns at transmission and by a software supported post-beam steering (PBS) at reception. Furthermore the antenna field can be subdivided into 6 individual subgroups (4x6 antennas) which can be connected with the 6 channels receiving system for interferometric applications. Height profiles of the 3-D wind vector and of the radar reflectivity can continuously and unattended be derived by the Spaced-Antenna (SA) and the Doppler-Beam-Swinging (DBS) method.
|Peak power||90 kW|
|Mean power||4,5 kW (@ 5% Duty Cycle)|
|Pulse length||1 ... 32 µs|
|Pulse repetition frequency||< 50 kHz|
|Height Ranges||(0,4) 1 ... 18 km (65 ... 95 km)|
|Height resolution||150 m, 300 m, 600 m, 1000 m|
|Time resolution||~ 1 min|
|Transmission signal||Single pulse, Complementary codes|
|Pulse form||Rectangle modified Gauss (for maximum power)|
In Spring 2014 the OSWIN antenna array was refurbished completely. The new antenna array based on the hexagonal structure of the MAARSY antenna array consists of 133 tree-element Yagi antennas arranged in 19 subgroups of 7 antennas each. Three adjacend subgroups are combined to 6 subgroups respectively at the moment and connected to the existing 6-channel transmit-receiving-system allowing spaced antenna operation for wind measurements.
Using the MAARSY structure of the antenna array is aligned on a future modernisation of the OSWIN radar. The aim is to bring the OSWIN radar technology to the same level as MAARSY. In a first phase, the existing 6-channel transceiver system will be replaced by a 19-channel transceiver system. The final stage will provide 133 transceiver-modules, each connected to one of the 133 Yagi antennas. As with MAARSY the radar beam can be pointed from pulse to pulse in any direction, allowing three dimensional measurement in the atmosphere. In addition, the new OSWIN radar will be equiped with improved receiver technology and an extended modularity and functionality, which will make it possible to operate the radar at different frequencies and with remote receiving units. By using the same technological base design at MAARSY and OSWIN synergy with the technical support and the operation of the systems will be achieved in addition to the resulting scientific opportunities as well.