2.11.2 Pre-flight Characterisation Measurements

In order to provide the required image quality, the two-way antenna beam pattern should be known to a high degree of accuracy (0.1dB). The transmit and receive antenna patterns have been accurately measured on ground 2.11.7. for all eight beams (IS1-IS7 and SS1) and both horizontal and vertical polarisations. The radiating performances of the antenna were measured in the Large Planar Near Field Range at Astrium Ltd (Portsmouth). Full characterisation was performed: 8 beams, two modes (transmit and receive), two polarisations (V and H), in copolar and crosspolar components.