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Methods of Plane Tabling.

 

Methods of Plane Tabling

Plane tabling is a method of surveying in which fieldwork and plotting are done simultaneously12. This method is generally adapted for surveys where high precision is not required and is mainly employed for small-scale or medium-sized mapping12.

Plane Table Survey Instruments

The equipment needed in plane table surveying is straightforward and almost available everywhere1. Here are the main instruments used:

1.  Drawing Board: Made of well-seasoned wood, it varies in size. The board may be mounted on a tripod with a leveling head or a ball-and-socket arrangement1.

2.  Alidade: A ruler with a sight line attached, used on the plane table for bisecting the object, drawing rays, direction lines, etc1.

3.  Spirit Level: Used to level the table by placing the spirit level in two positions at right angles to each other1.

4.  Trough Compass: Used for indicating the direction of the magnetic meridian on the paper1.

5.  U-Frame or Plumbing Fork: Used for centering the table at a particular station1.

Principles of Plane Table Survey

The principles of plane table survey include leveling, orientation, and centering1.

Methods of Plane Tabling

There are four main methods of plane tabling3:

6.  Radiation Method: This method is employed for locating details.

7.  Intersection or Triangulation Method: Another method used for locating details.

8.  Traversing Method: Used for locating the position of the plane table station on the drawing sheet.

9.  Resection Method: Another method used for locating the position of the plane table station on the drawing sheet.

Each of these methods has its own unique procedures and applications.

Advantages and Disadvantages

Like any surveying method, plane tabling has its advantages and disadvantages. It's simple and easy, with the map of the land prepared while doing the fieldwork2. However, it may not be suitable for areas where high precision is required1.


Source(s)

1. Plane Table Surveying | Its Methods, Advantages ... - CivilSeek

2. Plane Table Surveying – Methods, Examples & Uses - Civil Planets

3. Methods of Plane Tabling | Civil Engineering X

4. Plane Table Surveying : Objectives, Instruments And Adjustments
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