The Envisat-1 Advanced Synthetic Aperture Radar instrument

The Advanced Synthetic Aperture Radar (ASAR) selected for the ENVISAT-1 mission of the European Space Agency, is a sensor of paramount importance for the remote sensing community due to its enhanced flexibility with respect to the ERS AMI. The combination of different spatial resolutions, incidence angles, swath width sizes and polarisation diversity will reflect in an increased number of operational modes tailored for a large set of scientific and operational applications. The use of an active antenna concept, a digital generation waveform technique and a block adaptive quantization compression scheme are among the innovative design features of this radar. In this paper, the status of the ASAR instrument development is described, the accomplished project milestones will he highlighted together with preliminary instrument performance.