The goal of this work was to determine experimentally the properties of surfactant monolayer at a gas-liquid interface. Newly developed software allowed for determination of dilatational viscosity and elasticity of DPPC monolayer adsorbed at a periodically compressed and expanded interface of water or CTAB solution. The results indicated that reorganization of the interfacial film leads to different values of surface rheological parameters, which depend both on the temporal surface pressure and the direction of surface deformation.