How do you do a Tacheometric survey?
Determination of Tacheometric Constants on Field
- Measure a line (about 100m long) on the fairly level ground and drive pegs at some interval, say 50 meters.
- Keep the staff on the previously determined station and observe the corresponding staff intercepts (upper and lower stadia reading) with horizontal sight.
What are the instruments used in Tacheometric surveying?
The instruments employed in tachometry are the engineer’s transit and the leveling rod or stadia rod, the theodolite and the subtense bar, the self-reducing theodolite and the leveling rod, the distance wedge and the horizontal distance rod, and the reduction tacheometer and the horizontal distance rod.
Where is Tacheometric survey most used?
Definition of Tacheometry: Thus it is best suited when obstacles such as steep and broken ground, deep ravines, stretches of water or swamps are met with Tacheometry is mainly used while preparing contour plans and traversing and is also suitable for hydrographic surveys, location surveys of roads, railways, etc.
What is the principle of Tacheometric surveying?
What is the principle of tacheometric surveying? The principle of tacheometric surveying is based on the property of an isosceles triangle i.e the ratio of the distance of the base from the apex and the length of the base is always constant.
How do you find the Tacheometric constant?
By using tacheometric equation. D= f/i S + ( f + d ), since vertical angle is zero. Solving the above two equations to get the values for K and C. Similarly find out the values for K and C, by other set of readings.
In what circumstances Tacheometric surveying is advantageous?
The advantages of tacheometric surveying over the direct method of measuring horizontal distances and difference in elevations are: Speed of surveying is very high. Accuracy of surveying is quite satisfactory in normal conditions and even superior in difficult terrain. Cost of surveying is less.
What is the advantages of Tacheometric surveying?
It is one of the fastest methods of surveying. The accuracy of tacheometric surveying in uneven or difficult terrain is quite satisfactory. Does not require any tedious jobs with tapes and chains.
What are Tacheometric constants and how are they determined explain?
PROCEDURE: The stadia interval factor (k) and the stadia constant (c) are known as tacheometric constants. Before using a tacheometer for surveying work, it is required to determine these constants. These can be computed from field observation by adopting following procedure.
What are the errors in Tacheometric surveying?
The errors may be instrumental errors, due to manipulation and sighting or due to natural causes. The instrumental errors may be due to imperfect permanent adjustments in the instrument and due to incorrect graduations on the stadia rod.
Which operations are completely eliminated in Tacheometric surveying?
Explanation: Using tacheometric methods, elevations can also be determined. It is in fact a branch of angular surveying in which both the horizontal and vertical positions of points are determined from the instrumental observations, the chain surveys being entirely eliminated.
What are the various methods employed in Tacheometric survey?
Different systems of Tacheometric Measurement: The various systems of tacheometric survey may be classified as follows: The stadia System (a) Fixed Hair method of Stadia method (b) Movable hair method, or Subtense method The tangential system Measurements by means of special instruments The principle common to …
Which type of measurements are avoided in Tacheometric survey?
Therefore, to avoid this error, taking readings in the mid-day should be avoided as far as possible. Also, the lines of sight should not be within a meter from the ground. The average permissible error in the distance is 1 in 500 to 1 in 900 and in elevations 0.08 to 0.10 m.
How Tacheometric constants are determined in the field?
The stadia interval factor (k) and the stadia constant (c) are known as tacheometric constants. Before using a tacheometer for surveying work, it is required to determine these constants. These can be computed from field observation by adopting following procedure.
What do you mean by Tacheometric surveying and also write its advantages over other methods?
Tacheometric Surveying is defined as the branch of angular surveying in which the horizontal and vertical distances of points are determined through optical means. This type of surveying is faster as well convenient than chain or tape surveying. The accuracy of this surveying ranges from 1/1000 to 1/10000.
What are the advantages of Tacheometric survey?
It is one of the fastest methods of surveying. The accuracy of tacheometric surveying in uneven or difficult terrain is quite satisfactory. Does not require any tedious jobs with tapes and chains. Cost efficient with relative to time.
How is tacheometric surveying done?
Tacheometric Surveying is done with the help of Tacheometer and Stadia Rod. To read details of the tacheometric surveying instruments click the following link: The various methods of the tacheometric survey may be classified as follows: A brief description of these methods is given below.
Where is tacheometry desirable?
Tacheometry is desirable where taping and chaining are difficult (i.e. in broken grounds, deep ravines, swampy areas, stretches of water bodies etc.) 1. Introduction
What are the objectives of tacheometry?
The primary object of tacheometry is the preparation of countered plans. It is considered to be rapid and accurate in rough country and has thus been widely used by engineers in location surveys for railways, canals, reservoirs, etc. Tacheometry provides more accuracy on distances measured with a tape or a chain. Advantage of tacheometry surveying
What is the accuracy of tacheometry distances?
The accuracy of tacheometry distances is such that under favorable conditions, the error seldom exceeds 1 in 1000. The primary object of tacheometry is the preparation of countered plans. It is considered to be rapid and accurate in rough country and has thus been widely used by engineers in location surveys for railways, canals, reservoirs, etc.