Elastic scattering, total cross section and luminosity measurements at ATLAS

The ATLAS strategy to monitor and measure the absolute LHC luminosity will be reviewed. The absolute luminosity will be extracted from the measurement of the t-distribution of the elastic pp scattering in the CNI region, as performed during dedicated runs with specific beam optics. A luminosity monitor to be precisely calibrated during the elastic scattering parametrization will also be working in high-luminosity running conditions, where it will provide online luminosity values for both beam monitoring and data analysis. The detector designs, installation plans and expected performances will also be reported.