Abstract: In the construction of huge engineering projects,like Superconducting Super Collid-er (SSC),several problems of precise engineering surveys need special attention. Selection of projection techniques and rigorous reduction of geodetic observations are one of the important issues. This paper focuses on the SSC project. In the project the stereographic double conformal projection method is employed. The rigorous procedures for the reduction of GPS observa-tions, gyroazimuths, horizontal angles, and EDM distances from the ellipsoid to the selected mapping plane are discussed.