8 Plane Table Surveying CE 103

Plane Table Survey Basics

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For quick and approximate surveying, when great precision and accuracy is not needed, plane table surveying techniques is very suitable.

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It is particularly convenient for filling the details between the stations already fixed and surveyed by more precise method of triangulation or theodolitetraversing.

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For small area surveys, plane table is recommended.

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The great advantage of this technique is that field work and map plotting is achieved simultaneously by use of graphical surveying.

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The principle used in plane table surveying is that an unknown point of interest can be established by measuring its directions from known points

Advantages of Plate Table Survey

•(a) Plane table survey is most suitable for preparing small‐scale maps. It is most rapid.

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(b) The field book is not necessary as plotting is done in field concurrently with the field work, and hence the mistakes in booking the field notes are avoided.

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(c) The surveyor can compare the plotted work with the actual features of the area surveyed and, thus, cannot overlook any essential features.

(d) There is no possibility of omitting the necessary measurements as the map is plotted in the field.

(e) Errors of measurements and plotting may be readily detected by check lines.

(f) It is less costly than a theodolitesurvey.

(g) No great skill is required to prepare a satisfactory map.

Disadvantages of Plate Table Survey

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(a) The plane table is essentially a tropical instrument. It is not suitable for work in a wet climate.

(b) It is heavy, cumbersome, and awkward to carry.

(c) There are several accessories to be carried and, therefore, they are likely to be lost.

(d) It is not intended for accurate work.

(e) If the survey is to be re‐plotted to a different scale or quantities are to be computed, it is of great inconvenience in absence of the field notes.