  The Alpha Magnetic Spectrometer (AMS), to be installed on the International
Space Station (ISS) in 2008, will be equipped with a proximity focusing Ring
Imaging CHerenkov detector (RICH). This detector will be equipped with a dual
radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of
680 photomultipliers and light-guides, enabling measurements of particle
electric charge and velocity. A likelihood method for the Cherenkov angle
reconstruction was applied leading to a velocity determination for protons with
a resolution around 0.1%. The electric charge reconstruction is based on the
counting of the number of photoelectrons and on an overall efficiency
estimation on an event-by-event basis. Results from the application of both
methods are presented.
