Understanding Leveling Procedures for Benchmark and Temporary Benchmark Points

[chetzread]

Homework Statement

is it a must that that the levelling work must commence and ends at benchmark or temporary benchmark of known point ?

Homework Equations

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

 

[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 .

 

[chetzread]

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 .

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

 

[Nidum]

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

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 .

 

[chetzread]

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 .

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 ...

 

[chetzread]

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 .

Can you explain further ?

 

[Nidum]

Have a look through these :

Modern surveying methods

Automatic[/PLAIN] laser levelling

Site setting out with laser levels

 

[chetzread]

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 doesn't explain about it .