Contrarotative antennas studied for the European Meteosat satellite

The Meteosat system inserts itself in the overall Atmospheric Research Problem and constitutes the European contribution to this program. By means of geostationary satellites stabilized by rotation, the radiometric images of the earth are taken in the infrared and visible spectrum. These images transmitted to the ground make it possible to elaborate meteorological information on the circulation of winds, and cloud temperatures. One of the tasks of this satellite is the retransmission of documents treated by the WEFAX images, drawn from the high resolution image taken by the satellite. Two channels of 10 W are transmitted in the 1690 to 1695 MHz band by an antenna illuminating the whole earth and of which the contrarotative is controlled electronically. The principal problems related to this type of antenna are presented.