1. A method for generating an artifact-free magnetic resonance image data set comprising: acquiring magnetic resonance measurement data from an examination subject located in a measurement volume of a magnetic resonance data acquisition unit by operating the data acquisition unit according to a magnetic resonance data acquisition pulse sequence in which magnetic field gradients, which spatially encode said measurement data, are ramped continuously over time to a predetermined gradient strength for acquiring said measurement data, with no abrupt changes in said gradient strength; measuring actual magnetic field gradients that are present in said measurement volume of said data acquisition unit with a field mapping device located in said measurement volume; in a processor supplied with the measured actual magnetic field gradients, automatically calculating, based on the measured actual magnetic field gradients, trajectories along which said measurement data are entered into k-space during acquisition of said measurement data; in said processor, reconstructing an artifact-free magnetic resonance image data set from the acquired measurement data, dependent on the calculated trajectories; and making the artifact-free magnetic resonance image data set available at an output of said processor in electronic form as at least one data file.