Status and characterisation of COMPASS RICH-1

COMPASS RICH-1, a gas-radiator RICH detector with large transversal dimensions, which makes use of MWPC with CsI photocathodes as photon detectors, is in operation at COMPASS since 2001. The behaviour of the detector components is optimised and fully understood. The characterisation of the detector is now complete. We report about the detector status and its response in the COMPASS environment.