Abstract: A method for providing information related to the compaction state of a soil when performing a compaction operation with a soil compactor comprises the operations: a) detecting a vertical acceleration and a horizontal acceleration of a vibratory roller when moving a soil compactor over a soil to be compacted, b) determining a measurement relationship between a ground contact force (Fb) and a deflection (sw) of the vibratory roller for one vibration cycle using the vertical acceleration and horizontal acceleration detected in operation a), c) determining a simulation relationship (ZS) between the ground contact force (Fb) and the deflection (sw) for one vibration cycle using a ground model taking into account at least one simulation parameter, d) comparing the simulation relationship (ZS) to the measurement relationship, e) determining that a default value of the at least one simulation parameter taken into account in the ground model substantially represents a corresponding soil parameter of the soil to be