reciprocal leveling

noun

, Surveying.

1. leveling between two widely separated points in which observations are made in both directions to eliminate the effects of atmospheric refraction and the curvature of the earth.

More About Reciprocal Leveling

What is reciprocal leveling?

Reciprocal leveling is a surveying technique in which readings are taken from both directions between two points in order to reduce errors.

In surveying, to level is to find the relative elevation of different points in the land. Reciprocal leveling is useful when you are leveling between two points that are very far from each other. At far distances, the earth’s curvature and atmospheric refraction can cause significant leveling calculation errors, more than at short distances.

For example, you have point A on one side of a canyon and point B on the other side. You position your surveying device close to point A and measure its distance from the ground. From the same position, you measure point B’s distance from the ground. Next, you take your equipment across the canyon close to point B. Now, you take the same two measurements you did before but from the opposite direction. By calculating the difference between these two pairs of measurements, you can determine what the leveling error is to arrive at what a truly level line would be.

Why is reciprocal leveling important?

The term reciprocal leveling dates back to at least the late 1800s. This technique is used to survey across large distances, such as across rivers or other natural formations. Reciprocal leveling depends on reciprocal (matching) pairs of measurements to get a more accurate reading.

Because the reciprocal leveling uses the same two points for its calculations, the error should be identical when measuring from either side. So, we simply need to calculate the height difference between the two pairs of points.

Did you know ... ?

To lessen the variability of refraction, the best time to perform reciprocal leveling is between 10 a.m. and 3 p.m.

What are real-life examples of reciprocal leveling?

Reciprocal leveling is often used when surveying over long distances, especially across rivers or over a pit.

Reciprocal leveling is most familiar to people who perform surveying, such as engineers or geographers.

2. Reciprocal Leveling
-employed to determine the difference in elev. between two prints when its difficult or impossible to keep backsight and foresight short & equal such condition usually exist when measuring a line across side rivers, lakes or in rugged terrains

— tokio (@rstnejne) December 4, 2019

What other words are related to reciprocal leveling?

• level
• surveying
• elevation
• measurement
• curvature
• refraction

Quiz yourself!

True or False?

Reciprocal leveling is performed in order to eliminate calculation errors caused by the earth’s curvature and atmospheric refraction.