What is datum line in survey?

A datum line is a point of reference or standard for comparison. The term is primarily used in reference to surveying and engineering, where it is used in the measurement of depths and heights. read more

A geodetic datum is an abstract coordinate system with a reference surface (such as sea level) that serves to provide known locations to begin surveys and create maps. In this way, datums act similar to starting points when you give someone directions. read more

In general, a datum line is a tool used by engineers to ensure the accuracy of measurements. Engineers use the datum line as a horizontal base line to exactly measure various heights. Datum lines are valuable in the development of railway plans, as well as other complex engineering drawings. read more

MSL is the datum level or datum line in this case. The term datum line was originally used in surveying, navigation and geodesy. Later on, this was introduced as a loan word in other fields that involves one or the other kind of measurement or survey or objective assessment and comparison, namely economics, economy, market survey, population survey, setting up index, and so on. read more