What is orientation of plane table? State the procedure of any one method of orientation.

1 Answer

Answer :

Orientation of plane table: It means placing table in parallel positions at all stations (or at successive station)

1. Orientation using trough compass: Here north direction is marked at first station. When orientation is to be carried out at any station, then trough compass is placed along the north direction marked at first station and table is rotated till the needle exactly shows north direction (read zero). The table is clamped in this position. 

2. Orientation by back sighting: In this method, when orientation is to be carried out at any station, then alidade is kept along the ray already drawn on sheet from previous station to this station. That table is rotated till ranging rod at previous station is exactly bisected. The table is then clamped. 

Related questions

Description : Describe back sighting method of orientation of plane table surveying.

Last Answer : Backsight method of orientation 1. Assume we have to orient the table at next station B' represented on paper by point b'. 2.the line ba' is drawn on previous station A'. 3.the alidade is kept ... A'. 4. When the plotted line ab' coincides with line AB' and table will be oriented.

Description : Explain Orientation of plane table by Back-sighting Method.

Last Answer : Ans:- The method of setting up the plane table at each of the successive stations parallel to the position it occupied at the starting station is known as an Orientation. Orientation must be done when ... and bisection of the ranging rod at a are perfect then orientation is said to perfect.  

Description : Explain with neat sketch the procedure of radiation method of plane tabling.

Last Answer : 1. The table is set at suitable station e.g. P from where all stations can be sighted and measured. 2. After centering and leveling, mark station P as P' on sheet. 3. Suppose stations A, B, C, and D are ... marked as pa. 5. Similarly station B, C and D are bisected and marked as b, c and d.

Description : Define orientation and principle of plane tabling. 

Last Answer : Orientation: The orientation of plane table means keeping the plane table at all stations parallel to the position it occupied at first station. Principles of plane table survey: 1. The rays drawn from ... same as that of previous station i.e. orientation should be done at each changed station.  

Description : Define orientation. State two methods of orientation. Which method is most accurate and why? 

Last Answer : Orientation is the process of keeping plane table in same position as that is occupied in previous station. Methods of orientation: i) Magnetic meridian method using trough compass ii) Back ... and not by using trough compass. Therefore there is no error occurring due to local attraction.

Description : Draw sketch and explain method of traversing of plane table surveying. 

Last Answer : Procedure: 1.Set plane table over station A use plumbing fork for transferring station point from ground on sheet. Draw the direction of magnetic meridian with the help of compass. 2. With the ... scale Similarly, the table can be set at other successive station and traverse is completed.

Description : Explain the radiation method of plane table survey with neat sketch. 

Last Answer : This method is used when all the points to be plotted are visible from single instrument station. Steps are: 1. Select a suitable point P on the ground such that all the details are visible from it. 2. Center and ... , pc, pd, pe respectively. Join a, b, c, d, and e to give the outline.

Description : Explain ‘Intersection Method’ of plane table surveying with neat sketch. Also give situation when intersection method is used.

Last Answer : 1. Lay out a base line AB and measure it and Plot a distance ab' on sheet using any scale. 2.Set up instrument at A' with a' over A' 3.Orient the table by placing alidade ... the case of the survey of mountainous country. 5. The only linear measurement required is that of a base line.

Description : Describe in brief resection method of plane table surveying.

Last Answer : This method is used for establishing the instrument stations only. After fixing the stations, details are located either by radiation or intersection. The characteristic feature of resection is that the point ... of resection are (1)The Two Point Problem, and (2)Three Point Problem.

Description : What is meant by orientation? Explain orientation by back sighting method

Last Answer : Orientation: The method of setting up the plane table at each of the successive stations parallel to the position it occupied at the starting station is known as orientation. Orientation by back sighting: ... ranging rod at A are perfect, then the orientation is said to be perfect.  

Description : State the situation where plane table is suitable. 

Last Answer : 1) It is most suitable for preparing small scale maps 2) It is suitable in magnetic are where compass survey is not reliable 3) It is most suitable for filling in details between stations fixed by triangulation 4) It is suitable where accuracy is not required.

Description : State advantages of plane table survey one each with respect to booking and suitability

Last Answer : Booking of observations: i) Field work and plotting work done simultaneously ii) ) Notes of measurement are seldom required and possibility of mistakes in booking is eliminated. Suitability of PT ... and work where great accuracy is not required. ii) Mostly suitable for survey in plain terrain

Description : State merits and demerits of plane table survey. 

Last Answer : Merits: 1) It is the most rapid method of surveying.  2)There is no need for field book as plotting is done along with the field work, so the problem of mistakes in booking field notes does not arise. ... to carry. 5) The map cannot be replotted to defferent scale as there is no field book. 

Description : State the use of alidade in plane table surveying

Last Answer : 1) It is used for sighting the objects to be located.  2) It is used for drawing the rays. 

Description : State the principle of plane table survey. 

Last Answer : Principle of plane table survey 1. The rays drawn from different points should pass through a single point i.e. position of station point.  2. The position of table should be same as that of previous station i.e. orientation should be done at each changed station.

Description : State four advantages and four disadvantages of plane table survey

Last Answer : Advantages: 1. A field book is not required. 2. Errors of booking in field book avoided. 3. Errors of plotting can be readily checked. 4. Suitable in magnetic area. 5. Survey work with ... cannot be done in rainy season. 5. Difficult to re-plot as field notes are not available.

Description : State the limitations of plane table surveying.

Last Answer : 1) It is not suitable for work in wet climate 2) Several accessories are required to be carried hence possibility lost. 3) Replotting of survey work to different scale is difficult in absence of ... ) It is not intended for accurate work. 6) The plane table is essentially a tropical instrument.

Description : State the suitability of plane table survey

Last Answer : The plane tabling is generally suitable for surveys in which high precision is not required. It is mainly employed for small-scale or medium size mapping.

Description : Explain temporary adjustment of plane table survey.

Last Answer : 1. Setting over the station: The plane table is fixed on tripod and adjust the table in such a way that table is approximately level. 2. Leveling the table: The tubular or spirit level is placed in two ... . The table can be oriented in two ways. i. Using trough compass. ii. By back sighting.

Description : List any four accessories required for plane table survey.

Last Answer : 1. Plane table. 2. Plumbing U-fork. 3. Alidade. 4. Spirit level. 5. Trough compass. 6. Plumb bob.

Description : Describe in brief errors in plane table survey.

Last Answer : 1) The board not being horizontal. 2) The table not being accurately centered. 3) The table not being Correctly oriented. 4) The objects not being sited accurately. 5) The alidade not being ... through the station point. 7) Inaccuracy in plotting. 8) The expansion and contraction of the paper.

Description : Enlist different accessories of plane table survey with their use. 

Last Answer : i) The plane table: It is used for fixing a drawing sheet over it.  To locate the position of the objects on the sheet by drawing rays and plotting to suitable scale. ii) The Alidade (plain Alidade ... v) U-Fork or Plumbing fork with plumb bob: It is used for centering the table over the station. 

Description : Write any four advantages of intersection method of plane tabling over radiation method of plane tabling.

Last Answer : Advantages of intersection method: 1. Interection method requires less ground distance measurement than radiation method. 2. By this method we can locate inaccessible points which cannot be ... to radiation method, intersection method eliminates undulation error, bisection error and plotting errors.

Description : Compare collimation plane method and rise and fall method of reduction of levels.

Last Answer : The comparison between collimation plane method and Rise and fall method is given below. Collimation plane method Rise and Fall method 1 1. It is rapid method as it involves few calculations. ... Arithmetic check in this method is ΣBS - ΣFS = ΣRise - ΣFall = Last RL - First RL

Description : Explain intersection method of plane survey.

Last Answer : Intersection method of plane tabling 1. Lay out a base line AB and measure it and Plot a distance ab' on sheet using any scale. 2.Set up instrument at A' with a' over A' 3.Orient the table by ... sighted rays bd, bg, bf, bc are drawn to determine points intersection, d, g, f, c.

Description : Differentiate between plane of collimation and rise and fall method.

Last Answer : S.N Rise and fall method Plane of collimation 1 It is slow and more tedious. It is more rapid and less tedious  2 It is laborious as it involves more calculations. It is simple ... .S.-ΣF.S=ΣRise-Σfall =Last RL-First RL Arithmetical check ΣB.S.- ΣF.S=Last RL-First RL

Description : State the procedure to find the foot of the perpendicular on the chain line to take the offset. 

Last Answer : Ans: By cross staff 1. The cross staff is held vertically on the chain line where the offset is likely to occur. It is turned until one pair of opposite slits is directed to the ranging rod ( say ... the ranging rod at B. 3. The point P1 vertically under the instruments is required point. 

Description : Draw sketch and write the procedure for setting offset to the left or right side of suvey line with open cross-staff.

Last Answer : Procedure for setting offset with open cross staff : 1. Keep the ranging rods at point P(fixed on survey line) and at point A1 approximately. 2. The cross staff with stadia rod is fixed ... can be fixed and perpendicular offset AB is said to be set to given survey line PQ in left side.

Description : Describe the procedure of indirect ranging.

Last Answer : Procedure of indirect ranging. 1. If two stations i.e. A and B are not visible, then two intermediate points M1 and N1 are selected such that both stations will be intervisible from it. 2. ... continued till final points M and N are in line with AB, thus, ranging is said to be completed.

Description : Explain the procedure for profile leveling with neat sketch. 

Last Answer : 1) Let PQR be the given line of section.   2) Mark point at 10 m intervals on this line. 3) Level is set up on a firm ground at a suitable point I1. 4) Temporary adjustment of level is done and B. ... and set up on firm ground at I2 as before. 10) B.S is taken on CP1 and new HI is calculated  

Description : Explain Procedure for chain and compass traversing.

Last Answer : Chain and compass traversing : 1) Reconnaissance of the area to be surveyed is done. 2) Traverse stations are fixed. 3) The F.B and B.B of the traverse are measured by prismatic compass and ... occur when the traverse is plotted. 6) This error is adjusted graphically by using Bowditch Rule'. 

Description : Explain the procedure of profile leveling for construction of road.

Last Answer : The operation of taking levels along the center line of any alignment at regular interval is called longitudinal or profile leveling. Along the alignment, spots are marked at regular interval along ... points are plotted against their chainage to obtain ground profile along the alignment.

Description : With neat sketch, write the procedure of measurement of fore bearing with compass.

Last Answer : For measuring fore bearing of line AB, i) Place the compass over station A, center and level it.  ii) Looking through eye slit towards object vane, bisect the ranging rod at station ... which coincides with horse hair at observer end. The observed reading is the fore bearing of line AB

Description : Explain with neat sketch the procedure of reciprocal ranging.

Last Answer : Reciprocal ranging / Indirect ranging Procedure: Let A and B be two survey stations. They are not mutually visible due to high ground between them. Let two assistant stands at M1 and N1 as ... and N1 which are nearer to line AB. Repeat same process until points M and N are established. 

Description : State any two uses of Plane Surveying. 

Last Answer : 1) Plane surveying is used for measuring small distance. 2) When area is less than 260 km2, plane survey is normally done. 3) When desired accuracy is less, plane survey is done.

Description : To orient a plane table at a point roughly south of the mid-point of two inaccessible conical hill stations and in the plains, a point is selected in line with AB and table is oriented at by bringing ab ... , is (A) Unique and correct (B) Incorrect (C) Manifold and correct (D) Not reliable

Last Answer : (C) Manifold and correct

Description : Describe any one method of orientation of plane table surveying

Last Answer : Orientation by back sighting method: This method is accurate and is always preferred. Procedure: 1.Suppose A and B are two stations.The plane table is set up over A. The table is leveled by spirit level ... are perfect and needle is exactly at 0-0 , the orientation is said to be perfect.

Description : Explain errors occurred due to manipulation and sighting in plane tabling.

Last Answer : i) The board not being horizontal- This error affects chiefly the measurement of vertical angles. ii) The table not being accurately centered. The plotted position of the occupied station not ... and correct any displacement. v) The defective sighting- The object not being correctly sighted.

Description : Enlist the methods of plane tabling. 

Last Answer : Method of Surveying with the plane table are : 1) Radiation 2) Intersection 3) Traversing 4) Resection

Description : Differentiate between plane and geodetic survey on any four points. 

Last Answer : Difference between Plane Surveying and Geodetic Surveying Points Plane Surveying Geodetic Surveying Definition Plane surveying is that type of surveying in which mean surface of ... Traditional survey equipment is used Precise and modern survey equipment are required

Description : What are the sources of errors in plane tabling?

Last Answer : The following are the sources of errors in plane tabling 1) The board not being horizontal 2) The table not being accurately centered 3) The table not being Correctly oriented 4) The objects ... through the station point 7) Inaccuracy in plotting 8) The expansion and contraction of the paper 

Description : Describe stepping method of chaining on sloping ground.

Last Answer : 1. If A and B are the two points on sloping ground, for which horizontal distance is to be measured. 2. Unfold the chain. By touching handle to station A, stretch it up to maximum possible ... 6. Thus total horizontal distance on sloping ground is calculated as d(AB) = L1+L2+L3 in meters.

Description : Describe method of measuring distances on ground using chain and arrows.

Last Answer : Method of measuring distances on ground. 1. Mark the position of survey stations whose distance is to be measured using wooden peg. (say A and B) 2. now, ranging is done if distance ... station B. Thus total horizontal distance will be equal to addition of distances measured of each parts.

Description : Explain Direct method of chaining on sloping ground with neat skeetch. 

Last Answer : While chaining on sloping ground, the horizontal distances can be computed by direct method i.e. By stepping. By stepping: It consist in measuring the distance in small horizontal lengths (e.g.L1). Let ... is continued in the correct line with point B. Then length of line AB=L1 +L2 +L3+L4

Description : Compare Rise & Fall method and H.I. method. 

Last Answer : Sr.No.  Rise and Fall Method  H.I. Method  1 It is slow and more tedious.  It is more rapid and less tedious  2 It is laborious as it involves more calculations.  It is simple ... .S.- ΣF.S=ΣRise-Σfall =Last RL-First RL Arithmetical check ΣB.S.- ΣF.S=Last RL-First RL 

Description : With neat sketch, explain the included angle method of plotting compass traverse. 

Last Answer : 1. Calculate all included angles of the traverse from observed bearings of the lines. e.g. <A, <B, <C, <D, <E  2. Check sum of included angles as equal to ( ... coincide with starting station (in case of closed traverse). If there is closing error, it needs to be corrected. 

Description : Explain with neat sketch method of stepping of chaining on sloping ground.

Last Answer : Procedure : To measure the horizontal distance between points A & B on sloping ground following steps should be followed ( Refer above figure.) 1. Starting from point A, the chain is unfolded and ... . Finally calculate total chained distance as d(AB) = d(AP1) + d(P2P3) + d(P4P5)

Description : Differentiate between 'H.I. method' and 'Rise and Fall method' with respect to time, checks, application and simplicity. 

Last Answer : Sr. No. Point of difference H.I. method Rise and fall method 1 Time Less time required for calculations of RLs. More time is required for calculations ... simple, rapid involving less calculation.  Involves several calculations hence more laborious and time consuming.

Description : What is meant by closing error? Explain graphical method of adjustment of closing error.

Last Answer : Closing error: The distance by which the traverse fails to close is called closing error. Step 1 ) Draw a horizontal line AA1 Equal to the length of perimeter of the traverse to a suitable scale 1) Mark ... 6) Join the the new points which gives the closed traversed. A, B, C,D and A.

Description : Explain the process of chaining on sloping ground by stepping method with neat sketch.

Last Answer : The procedure to measure horizontal distance between the points A and B on sloping ground is as follows. 1. Two persons-leader and follower are required for chaining. 2. The follower holds the end of chain at A. The leader goes ... between A and b L = AM, + MN' + NO' + OP' + PQ' + QB'