The SITE module solves the site response problem. The control point and wave composition of the control motion has to be defined. The information needed to compute the free field displacement vector used is computed and saved on disk in File 1. The program also stores information required for the transmitting boundary calculations in File 2. The actual time history of the control motion is not required in this program module, but later in the MOTION module. The soil motion incoherency is introduced elsewhere, in the HOUSE module.