surveying iii (topographic and geodetic surveys) - Modern Prepper

LESSON 4LEVELINGOVERVIEWLESSON DESCRIPTION:In this lesson, you will learn to identify the different techniques of leveling.TERMINAL LEARNING OBJECTIVE:ACTION:CONDITION:STANDARD:You will identify the different techniques of leveling.You will be given the material contained in this lesson, a number 2 pencil, and acalculator.You will correctly answer all practice questions following this exercise.REFERENCES: The material contained in this lesson was derived from FM 3-34.331.INTRODUCTIONIn previous lessons we learned to triangulate from a known point to an unknown point in order to find itsposition and tape between two known points to establish a baseline for a triangulation net, but this is notall that is necessary to know about surveying or establishing known points on the earth's surface. Inorder to completely define the location of any point on the earth, we must also determine its exactelevation. This can be done through geodetic leveling.Geodetic leveling is the operation of measuring precise vertical distances above or below a reference ordatum. The datum universally used is MSL and is considered to be zero meters. MSL is the averageheight of the sea for all stages of the tide. The vertical distance above or below this datum then becomesthe elevation of that point. It is the surveyors job to run the levels in lines to determine the differences inelevation between points whose elevations are known and those whose elevations are required.For higher order surveys, various leveling methods and instruments can be used to accomplish this task.The spirit level and graduated rods are used for precise4-1 EN0593