The invention relates to an apparatus and method for imparting a precise amount of impulse energy to be delivered to the ground. The apparatus includes an anvil for operative deployment against the earth a hammer operatively connected to the anvil for striking the anvil; and a control system operatively connected to the hammer for controlling the impulse energy of the hammer striking the anvil. The control system includes a linear feedback system for measuring the linear position of the hammer with respect to the anvil during a force stroke and a processor for receiving linear position data from the linear feedback system for controlling the relative speed of the hammer with respect to the anvil during a force stroke through an actuation system.