What kind of measurement does the existing railway survey generally include?

The existing railway survey work can be divided into plane and control survey, topographic survey, mileage survey, midline survey (also known as plane survey), middle pile elevation survey, cross-section survey, hydrological survey and so on. In addition to control survey, other work can be carried out by RTK survey technology. —— Quoted from Practical Manual of GPS RTK Surveying Technology by People's Communications Publishing House.