Question

Which of the following error is most likely to occur in the plane table surveying?

• A. Error in orientation
• B. Error in sighting
• C. Error in levelling
• D. Error in measurement
  

Answer 1

The correct option is A Error in orientation

• Error in orientation is most likely to occur in the plane table survey.
• Orientation done with compass is unreliable, as there is every possibility of a local attraction. Errorless orientation contributes to the distortion of the survey. This orientation should be checked at as many stations as possible by sighting distance prominent objects already plotted.

Note: Error is sighting: The accuracy of a plane table mapping depends barely upon the precision with which points are sighted. The plain alidade with open sight is much inferior to the telescopic alidade with open sight is much inferior to the telescopic alidade in the definite on of the line of sight.

Error in leveling: The effect of non-horizontally of the board is more severe when the difference in elevation between the points sighted is more but this error can be removed easily with the help of a spirit level.