Ground-based (Bruker 125 HR) and satellite (OCO-2) datasets of simultaneous CO ₂ measurements in the vicinity of St. Petersburg were compared. Correction of the ground-based XCO ₂ values by 2.5% and the choice of the optimal setup during spectral analysis allowed good agreement to be reached between the satellite and groundbased measurements. The bias between the two datasets was –0.01–0.16 ppm (–0.00–0.04%), standard deviations of the means, 1.42–1.49 ppm (0.35–0.37%), with a spatial mismatch of the XCO ₂ data pairs of 100–300 km. Such small disagreement between the two types of measurements permits both methods to be used to solve the inverse problem of atmospheric transfer, i.e., estimation of anthropogenic emissions of CO ₂.