At the present time the European Space Agency is making preparations for a European remote-sensing-satellite programme. Within this programme, the first satellite to be launched will be an ocean-monitoring satellite ERS-1, whose payload will principally comprise active microwave instruments, namely a synthetic aperture radar (SAR), a scatterometer and an altimeter. To set up a proper basis for the discussion of the ground segment, the satellite and its payload are briefly introduced and the foreseen mission objectives of the programme are outlined. The paper then concentrates on that portion of the programme concerned with the ground facilities necessary for the control of the satellite on the one hand and payload data acquisition, processing, archiving and distribution on the other.