# Homework Help: Principle of leveling

1. Oct 22, 2016

1. The problem statement, all variables and given/known data
is it a must that that the levelling work must commence and ends at benchmark or temporary benchmark of known point ?

2. Relevant equations

3. The attempt at a solution
I think not , because we can commence the levelling work at a point of known elevation ( benchmark / temporary benchmark) and ends at point of unknown elevation

2. Oct 22, 2016

### Nidum

Levelling around a survey route from one fixed bench mark and back to the same bench mark provides a very reliable means of error checking . If the cumulative changes in elevation around the survey route amount to zero when you get back to the known bench mark then the probablity of having made measurement mistakes somewhere along the way is very small .

3. Oct 22, 2016

How about leveling start from known point to unknown point and back to known point? known point here means the point where the height is known

4. Oct 22, 2016

### Nidum

That is effectively the same thing . You can designate any fixed level as your benchmark level .

When levelling over relatively short distances - on for example a construction site - the simpler method of starting from a bench mark and just proceeding in one direction is sometimes used .

Modern laser surveying methods and coming of GPS have made most of the traditional surveying methods obsolete .

5. Oct 22, 2016

sorry , i mean how about levelling work start from a point where the height is known (benchmark) , and ends at a different point where the height is unknown ....

6. Oct 23, 2016

Can you explain further ?

7. Oct 23, 2016

### Nidum

Last edited by a moderator: May 8, 2017
8. Oct 24, 2016

is it possible that levelling work start from a point where the height is known (benchmark) , and ends at a different point where the height is unknown .... ?
I have read thru the link that upu provided , but seems they doesnt explain about it .