GEOGCS["GCS_Unknown_datum_based_upon_the_Average_Terrestrial_System_1977_ellipsoid",DATUM["D_Not_specified_based_on_Average_Terrestrial_System_1977_ellipsoid",SPHEROID["ATS_1977",6378135.0,298.257]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]]