What is the radiation method in plane table survey?

What is the radiation method in plane table survey?

In the radiation method of plane table surveying, the direction of the objects or points to be located are obtained by drawing radial lines along fiducial edge of alidade after getting the objects or points bisected along the line of sight of the alidade.

What is intersection method of plane table surveying?

2.INTERSECTION METHOD In this method the plane table is shifted to a known distance in a particular direction marked on the ground and the line of sights are drawn to make intersection of the radial lines already drawn from the first set up of the instrument.

What are the different methods of plane table survey?

Methods of Plane Table Surveying

• Radiation.
• Intersection.
• Traversing.
• Resection.

What is intersection in surveying?

Intersections are the group of planar surveying calculations where we use two control points (three in the case of resection) with known coordinates and certain angle/distance measurements to compute the coordinates of an unknown point.

What are the limitations of radiation method in plane table survey?

Disadvantages of the Radiation method The radiation method does not provide very accurate results. The radiation method is not suitable for surveying work in a wet climate. This method is not suitable where the stations are not visible.

Why intersection method is used in plane table surveying?

This method is useful where it is not possible to measure the distances on ground as in case of a mountainous country. Hence, this method is employed for locating inaccessible points, the broken boundaries, rivers, fixing survey stations, etc.

What is point of intersection in surveying?

What is the use of radiation in surveying?

Surveys provide a direct measure of area radiation levels and detect the presence of radioactive material inadvertently spilled on a person, surface or piece of equipment.

Which is not method of plane table surveying?

Which among the following is not a method of plane table surveying? Explanation: The methods which are adopted in case of plane table surveying involve radiation, Intersection, resection and traversing, which are used based on the type of output required. 2. The method of radiation is used when distances are small.

What is the intersection method of locating an unknown point?

Intersection is the location of an unknown point by successively occupying at least two (preferably three) known positions on the ground and then map sighting on the unknown location. It is used to locate distant or inaccessible points or objects such as enemy targets and danger areas.

What are the likely errors in intersection method?

The table on which the lines need to be drawn should be placed accurately. If the table is not accurately placed then it needs to be shifted to a balanced surface. The instruments should be fixed and do not move freely. The new lines should correspond with the previous lines.

How is the intersection of rays used in plane table surveying?

The intersection of rays from stations O1 and O2 will give points a, b etc. on paper, as shown in the figure. This is more or less like the compass survey. It is used for running survey lines between stations, which have been previously fixed by other methods of survey, to locate the topographic details.

Which is the radiation method of plane tabling?

(1) Radiation method of plane tabling: In this method of plain table survey, the plane table is set up at only one station, and various points are located by radiating (drawing) a ray from the instrument station to each of the points, and plotting to scale along the ray the distance measured from the station to the point is sighted.

How is the intersection method used in surveying?

Intersection method 3. Traversing method The plane table is set up over only one station from which the whole traverse can be commanded. It is suitable for survey of small areas. 1) Select a point “O ” so that all points to be located are visible from it. 2) Set up the table at “O”, level it, and do centering.

How are radiation, intersection and traversing methods used?

NOTE: By using radiation method, intersection and traversing methods we can locate the points on the paper, which were already on the ground. By using algebraic formulae, we can calculate the area of the given land. A, b are the parallel sides. h is the distance between parallel sides.