What was found
(CAN) UPON LANDING, AT APPROXIMATELY 300 FT, THE GPWS ANNUNCIATED A "TOO LOW - TERRAIN" WARNING. IT WAS APPARENT THAT THIS WAS A FALSE WARNING AS WE WERE ESTABLISHED ON THE GLIDESLOPE AND HAD 2 REDS AND 2 WHITES ON THE PAPI. AN UNEVENTFUL LANDING WAS COMPLETED. THE RADIO ALTIMETER HAD BEEN PROVIDING ERRONEOUS READINGS AND GIVING FALSE AURAL CALL-OUTS FOR THE PAST FEW DAYS AND HAD AN ADD RAISED AGAINST IT. NR 1 RADIO ALTIMETER REPLACED.