Measurement Tips

Thoughts on Orientation Distance Error △d of Total Station

Release date:2022-05-27     Author:Wyatt     Visitors:6915

 

 

When we're doing a directional operation with the total station, if the station coordinates or the back sight coordinates are entered incorrectly, for total station, there will no prompts for it. However, there are some tips to verify.

 

To set station orientation, there are many ways, including coordinate orientation, azimuth orientation, rear intersection and so on. If you choose to use coordinate orientation, the orientation distance error △d will be displayed on instruments when you measure point B through orientation survey by setting station at point A. △d namely means the difference between the theoretical distance AB and measured distance AB. If the error is found to be too large, it is obvious that there is something wrong, and it is greatly possible that the known coordinates are input incorrectly.

 

 




Here you shall know about the following several situations:

1.The error of coordinates for point A input by you is just only 1cm.   However, control point itself also has its error, and there will also have error when you set station and orientation point. Therefore, △d at least includes the above three kind of errors during orientation distance measurement, it is unable to be judged whether the errors are caused by incorrect input or by others.




2. If the azimuth of coordinates from station A to orientation point B is north and south, and the error of input value for y is 1cm, it also won't be reflected during orientation distance measurement.


In addition, it shall be paid attention to that distance measurement is needn’t for some instruments whose orientation can be finished by pressing key “OK” to pass the verification directly.

In conclusion, during measurement, it is recommended to import to instruments the coordinate data of control points and stakeout points as far as possible, rather than input on site, to avoid the possibility of on-site errors.