ERS-2 was launched in April 1995 with its primary instruments being an active microwave instrument (AMI), a radar altimeter, an along-track scanning radiometer, an ozone monitoring sensor and microwave sounder. The AMI comprised two seperate radars - a Synthetic Aperture Radar (SAR) and Wind Scatterometer. These enable 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 and ENVISAT 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 acquisitions information is stored in the EOLI catalogue (the Client for browsing the catalogue can be downloaded here).