Satellite measurements sample very large numbers of oil and gas sites at high frequencies, potentially allowing for rapid and comprehensive detection of events with emission rates >100 kg/h (Cardoso-Saldaña 2023). A key issue in the use of satellites in the identification of large methane emission events is determining detection limits. Detection limits for satellite systems have been assessed in a small number of controlled release tests with emission rates in excess of 1000 kg/h . Estimates of emissions based on satellite data, however, depend strongly on the methods used to convert the satellite observations of column loadings into spatially resolved emission rates. To assess the accuracy of quantification, provided primary data from a methane detection satellite observing a large-scale controlled release, in a desert region with no other nearby sources, to five different research groups for emission rate quantification. Despite having the same primary data, the range of estimates provided by the five groups ranged from -80% to +300% of the true controlled release emission rate. Identification of emission events from large emission events in regions with relatively large routine emissions will be even more challenging than for isolated controlled releases. Routine emissions will lead to column concentrations with complex spatial and temporal variability, and the signal of methane enhancements from emission events must then be detected within an already complex signal. Knowledge of expected background column concentrations due to routine emissions and the changes in those enhancements expected due to emission events of various magnitudes could help refine the ability of satellites to detect and quantify large methane emission events.