Concept: Plane-table survey: A plane table surveying is a
graphical method of surveying. In this method of surveying,
field observation and plotting are done simultaneously helping the surveyor to compare the plotted details with actual features of the ground.
Advantages of Plane Table Survey: ● It is suitable for the
location of details as well as contouring for large-scale maps directly in the field.
● As
surveying and plotting are done simultaneously in the field, chances of getting omission of any detail get less.
●The plotting details can immediately get compared with the actual objects present in the field. Thus errors, as well as the accuracy of the plot, can be ascertained as the work progresses in the field.
● The plane table survey is generally
more rapid and less costly than most other types of survey.
Disadvantages of Plane Table Survey ● The plane table survey is
not possible in unfavorable climates such as rain, fog, etc. ● This method of survey is
not very accurate and thus unsuitable for large-scale or precise work. ● As no field book is maintained, plotting at different scale require full exercise.
● The quality of the final map depends largely on the drafting capability of the surveyor.
For the plane table set-up:
From a similar triangle theorem:
Where S = Scale
Calculation: Scale
∴