The CANOPUS Meridian Photometer Array (MPA) was a ground-based photometer array for remote sensing the high latitude ionosphere during the ISTP/GGS program. The array comprises four meridian scanning photometers. The eastern line of three instruments were located close to the 337' magnetic longitude meridian; one instrument to the west was located near to the 313' magnetic longitude meridian. The CANOPUS program has been superseded by the CARISMA (Canadian Array for Realtime Investigations of Magnetic Activity).