The Observatory

The Fermi spacecraft supports two gamma-ray instruments; the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). The LAT is a wide-field gamma-ray telescope (20 MeV - 300 GeV) and is capable of surveying the entire sky at these energies in two orbits while operating in sky-survey mode, while the GBM surveys the entire sky in a single orbit. Understanding how the observatory takes data, as well as other systemic effects (e.g. various periodicities) is crucial to performing Fermi data analysis.