Calibration for extensive air showers observed during the JEM-EUSO mission

The Extreme Universe Space Observatory is a mission to investigate the highest energy cosmic rays by recording the extensive air showers they create in the Earth’s atmosphere. This will be done by observing these showers from low Earth orbit. These observations will be used to measure the flux, energies and arrival directions of these cosmic rays. This paper describes how the accuracy of these measurements will be tested and improved during the mission using the Global Light System (consisting of calibrated xenon flash lamps and lasers) located deep in the Earth’s atmosphere.