ERS-2 was launched in April 1995 with its primary instruments being an Active Microwave Instrument (AMI), a Radar Altimeter (RA), an Along-Track Scanning Radiometer and a Microwave Sounder (ATSR-2), and a Global Ozone Monitoring Experiment (GOME) sensor . The AMI instrument was comprised of two separate radars - a Synthetic Aperture Radar (SAR) and a Wind Scatterometer. These systems enabled three modes of operation - Image Mode, Wave Mode (both performed by the SAR) and Wind Mode (performed by the Wind Scatterometer).
Full details of the ERS-2 acquisition plan and the various modes of operation are provided here. The standard operational mode provided a 35 day repeat orbit. Special modes include the tandem mode (joint interferometric modes with ERS-2 SAR and ENVISAT ASAR and a 3 day repeat cycle at the end of the Mission). Tandem operation with ENVISAT occurred for:
The high-level operational plan describes in more detail the various operational phases of ERS-2. The ERS-2 SAR Image Mode acquisitions can be downloaded from the ESA Online Dissemination service here).