What is Tacheometric Surveying?
Tacheometric surveying is an angular surveying method that uses a tachometer to measure the horizontal and vertical distances between two points. It is a faster and more convenient alternative to chain or tape surveying, especially in difficult terrain such as broken ground, deep ravines, swamps, and water bodies. The accuracy of tacheometric surveying lies between 1/1000 and 1/10000.
Advantages of Tacheometric Surveying
Tacheometric surveying is a preferred method of surveying due to its speed and convenience. It is especially useful in terrain that makes chain or tape surveying difficult, such as broken ground, deep ravines, swamps, and water bodies. Additionally, the accuracy of this surveying technique ranges from 1/1000 to 1/10000.
Principle of Tacheometric Surveying
What is Tacheometric Surveying?
Tacheometric surveying is an angular surveying technique that uses a tachometer to measure the horizontal and vertical distances between two points. It is faster and more convenient than traditional chain or tape surveying, particularly in difficult terrain. The accuracy of tacheometric surveying ranges from 1/1000 to 1/10000.
Advantages of Tacheometric Surveying
Tacheometric surveying is a preferred surveying method due to its speed and convenience. It is especially useful when surveying difficult terrain such as broken ground, deep ravines, swamps, and water bodies. Additionally, the accuracy of this method is quite high, ranging from 1/1000 to 1/10000.
The Principle of Tacheometric Surveying
The principle of tacheometric surveying is based on the properties of an isosceles triangle. Specifically, the ratio of the distance of the base from the apex and the length of the base is always constant. The formula for the horizontal distance is determined using this principle.
H= K*s* cos ² θ
Note: The additive constant is 0.00, and the multiplying constant is 100.00.
The formula for the vertical distance for the same tacheometer is:
V= (K*s*sin2θ)/2 = Htanθ
Where,
s= staff intercept = Top Reading – Bottom Reading
K= Multiplying Constant (generally taken as 100)
θ = Vertical angle on the theodolite
What is Tacheometric Surveying?
Tacheometric surveying is an angular surveying method that uses a tachometer to measure the horizontal and vertical distances between two points. It is a faster and more convenient alternative to chain or tape surveying, particularly in difficult terrain. The accuracy of tacheometric surveying ranges from 1/1000 to 1/10000.
Advantages of Tacheometric Surveying
Tacheometric surveying is a preferred method of surveying due to its speed and convenience. It is especially useful in terrain that makes chain or tape surveying difficult, such as broken ground, deep ravines, swamps, and water bodies. Additionally, the accuracy of this technique lies between 1/1000 and 1/10000.
The Principle of Tacheometric Surveying
The principle of tacheometric surveying is based on the property of an isosceles triangle, wherein the ratio of the distance of the base from the apex and the length of the base is always constant. This ratio is applied to calculate the horizontal distance between two points. The formula for the horizontal distance is determined using the central wire reading (R) and the vertical distance value.
R.L of Point = R.L of Instrument Station + H.I ± V-R
Procedure for Tacheometric Surveying
What is Tacheometric Surveying?
Tacheometric surveying is an angular surveying method that uses a tachometer to measure the horizontal and vertical distances between two points. It is a faster and more convenient alternative to chain or tape surveying, especially in difficult terrain. The accuracy of tacheometric surveying ranges from 1/1000 to 1/10000.
Advantages of Tacheometric Surveying
Tacheometric surveying is a preferred method of surveying due to its speed and convenience. It is especially useful in terrain that makes chain or tape surveying difficult, such as broken ground, deep ravines, swamps, and water bodies. Additionally, the accuracy of this surveying technique ranges from 1/1000 to 1/10000.
Orienting the Instrument for Tacheometric Surveying
The tacheometric surveying technique is based on the property of an isosceles triangle – the ratio of the distance of the base from the apex and the length of the base is always constant. In order to orient the instrument, a reference point or another station of the traverse with reference to the first station must be known. The magnetic meridian or the real meridian can be used as the reference meridian
What is Tacheometric Surveying?
Tacheometric surveying is an angular surveying method that uses a tachometer to measure the horizontal and vertical distances between two points. It is a faster and more convenient alternative to chain or tape surveying, especially in difficult terrain. The accuracy of tacheometric surveying ranges from 1/1000 to 1/10000.
Advantages of Tacheometric Surveying
Tacheometric surveying is a preferred method of surveying due to its speed and convenience. It is especially useful in terrain that makes chain or tape surveying difficult, such as broken ground, deep ravines, swamps, and water bodies. Additionally, the accuracy of this surveying technique lies between 1/1000 and 1/10000.
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. The formula for the horizontal distance is determined using the vertical angle, the height of the instrument, and the staff readings.
Orienting the Instrument for Tacheometric Surveying
Orienting the Instrument for Tacheometric Surveying
Orienting the instrument
Methods of Tacheometric Surveying
Change the Station of the Instrument:
This step involves setting up the instrument, centering and leveling it, and measuring its height. A back sight is then taken to the first station, and the bearings, vertical angle, and staff readings are noted.
Check Precision of Measurement:
Determine Horizontal Distance:
The horizontal distance between an instrument Station “A” and a staff Station “B” is determined by the angle subtended at point “A” by a known distance at point “B” and the vertical angle from point “B” to point “A”.
Classification of Tacheometric Surveying:
Tacheometric surveying is further classified into two methods.
1. Stadia Method of Tacheometry
Change the Station of the Instrument:
This step involves setting up the instrument, centering and leveling it, and measuring its height. A back sight is then taken to the first station, and the bearings, vertical angle, and staff readings are noted.
Check Precision of Measurement:
In order to ensure the operation is accurate, the two values for the station’s distances and altitudes must be within the legal limits. If not, the operation must be redone.
Determine Horizontal Distance:
The horizontal distance between an instrument Station “A” and a staff Station “B” is determined by the angle subtended at point “A” by a known distance at point “B” and the vertical angle from point “B” to point “A”.
Classification of Tacheometric Surveying:
Tacheometric surveying is further classified into two methods: the stadia technique and the trigonometric technique. Both of these methods are used to calculate the horizontal distance and the vertical elevation between the staff station and the instrument station with only one observation from the instrument station.
A. Fixed Hair Method
Change the Station of the Instrument:
This step involves setting up the instrument, centering and leveling it, and measuring its height. A back sight is then taken to the first station, and the bearings, vertical angle, and staff readings are noted.
Check Precision of Measurement:
In order to ensure the operation is accurate, the two values for the station’s distances and altitudes must be within the legal limits. If not, the operation must be redone.
Determine Horizontal Distance:
The horizontal distance between an instrument Station “A” and a staff Station “B” is determined by the angle subtended at point “A” by a known distance at point “B” and the vertical angle from point “B” to point “A”.
Classification of Tacheometric Surveying:
Tacheometric surveying is further classified into two methods: the Stadia Technique and the Trigonometric Technique. The stadia technique is the most popular method adopted for calculating horizontal distance and vertical elevation with only one observation from the instrument station. This involves using a telescope with two extra cross-hairs, one above and one below the center hair, which are equally spaced from the center hair. When observed via
B. Movable Hair Method
Change the Station of the Instrument:
This step involves setting up the instrument, centering and leveling it, and measuring its height. A back sight is then taken to the first station, and the bearings, vertical angle, and staff readings are noted.
Check Precision of Measurement:
In order to ensure the operation is accurate, the two values for the station’s distances and altitudes must be within the legal limits. If not, the operation must be redone.
Determine Horizontal Distance:
The horizontal distance between an instrument Station “A” and a staff Station “B” is determined by the angle subtended at point “A” by a known distance at point “B” and the vertical angle from point “B” to point “A”.
Classification of Tacheometric Surveying:
Tacheometric surveying is further classified into two methods: the Stadia Technique and the Movable Hair Technique.
Stadia Technique:
2. Tangential Method of Tacheometric Surveying
Change the Station of the Instrument:
This step involves setting up the instrument, centering and leveling it, and measuring its height. A back sight is then taken to the first station, and the bearings, vertical angle, and staff readings are noted.
Check Precision of Measurement:
In order to ensure the operation is accurate, the two values for the station’s distances and altitudes must be within the legal limits. If not, the operation must be redone.
Determine Horizontal Distance:
The horizontal distance between an instrument Station “A” and a staff Station “B” is determined by the angle subtended at point “A” by a known distance at point “B” and the vertical angle from point “B” to point “A”.
Classification of Tacheometric Surveying:
Tacheometric surveying is further classified into two methods: the Stadia Technique and the Movable Hair Technique.
Stadia Technique:
The stadia technique of tacheometry is a popular method adopted for calculating horizontal distance and vertical elevation. The horizontal distance between the staff station and the instrument station and the elevation of the staff station along the instrument’s line of sight is computed using this approach with only
Errors and Precautions in Tacheometric Surveying
The commonly occurring errors in the tacheometric survey are due to the following reasons.
1. Instrumental Errors
Change the Station of the Instrument:
This step involves setting up the instrument, centering and leveling it, and measuring its height. A back sight is then taken to the first station, and the bearings, vertical angle, and staff readings are noted.
Check Precision of Measurement:
In order to ensure the operation is accurate, the two values for the station’s distances and altitudes must be within the legal limits. If not, the operation must be redone.
Determine Horizontal Distance:
The horizontal distance between an instrument Station “A” and a staff Station “B” is determined by the angle subtended at point “A” by a known distance at point “B” and the vertical angle from point “B” to point “A”.
Classification of Tacheometric Surveying:
Tacheometric surveying is further classified into two methods: the Stadia Technique and the Movable Hair Technique.
Stadia Technique:
This technique of tacheometric surveying involves using a telescope with two extra cross-hairs, one above and one below the center hair. The stadia hairs are then observed and the staff is seen to intercept a specific length of the staff. This is the
2. Manipulation and Sighting Error
Inefficiencies and Errors:
Errors in surveying can be caused by the surveyor’s lack of efficiency or expertise. These inaccuracies can be due to improper instrument centering and leveling, as well as incorrect stadia readings.
Impact of Poor Accuracy:
The consequences of these errors can have a detrimental effect on the accuracy of the survey results. If a surveyor is not skilled in the use of surveying instruments, their results may be inaccurate. This can lead to inaccuracies in the results of the survey and, ultimately, in the data that is used for decision-making.
Preventing Poor Accuracy:
In order to prevent these inaccuracies, surveyors must be trained in the use of surveying instruments and must be proficient in the techniques used to measure distances, angles, and elevations. Additionally, surveyors should always use the most current technology and instruments available to ensure the accuracy of their survey results. By following these steps, surveyors can help reduce the chances of inaccuracies caused by manipulation and sight.
# Wind as a Natural Source of Inaccuracies
Wind can lead to inaccuracies in measurements as it can cause instruments to move, resulting in readings being taken from the wrong location or at the wrong time. Additionally, wind can disrupt visibility by creating dust or other impurities in the air.
# Asymmetrical Expansion of Instrument Components
Advantages of Tacheometric Surveying
The following are some of the advantages of tacheometric surveying:
- The speed with which such a survey is conducted is quick.
- The procedure does away with the usage of tapes and chains. As a result, it is less time-consuming.
- It is a low-cost way of surveying.
- The precision of this approach is also good enough for the compilation of topographic maps, hydrological surveys, and cross-checking measurements from other methods, among other things.
FAQs
What is a tacheometric survey?
What is Tacheometric Surveying?
Tacheometric surveying is a technique of angular surveying that utilizes a tachometer to measure horizontal and vertical distances between two points, instead of the laborious chain surveying method.
Benefits of Tacheometric Surveying
Tacheometric surveying offers several advantages, including faster calculation of distances, increased accuracy, and the ability to survey inaccessible or difficult terrain. It also reduces the need for manpower and equipment, offering cost-savings and improved efficiency.
Applications of Tacheometric Surveying
Tacheometric surveying is widely used in many areas, including civil engineering, construction, mapping, and land surveying. It is also used for calculating elevations and for setting out boundaries and other objects.
What is the principle of tacheometric surveying?
Understanding the Principle of Tacheometric Surveying
Tacheometric surveying is based on the property of an isosceles triangle, which states that the ratio of the distance of the base from the apex and the length of the base is always constant. This allows the surveyor to determine the distance and elevation between two points with a tachometer.
Advantages of Tacheometric Surveying
Tacheometric surveying offers a number of advantages over traditional methods of surveying, such as faster calculation of distances, increased accuracy, and the ability to survey inaccessible or difficult terrain. Additionally, it reduces the need for manpower and equipment, providing cost-savings and improved efficiency.
Applications of Tacheometric Surveying
Tacheometric surveying is used in a variety of fields, including civil engineering, construction, mapping, and land surveying. It can be used for calculating elevations, setting out boundaries, and other surveying tasks.
What are the common errors in tacheometric surveys?
Common Errors in Tacheometric Surveying
Tacheometric surveying can be subject to a variety of errors, which can be attributed to instrumental, manipulation and sighting, and natural causes. Understanding the sources of these errors is essential for accurate tacheometric surveying.
Benefits of Tacheometric Surveying
Tacheometric surveying offers several advantages over traditional methods of surveying, such as faster calculation of distances, increased accuracy, and the ability to survey inaccessible or difficult terrain. Additionally, it reduces the need for manpower and equipment, providing cost-savings and improved efficiency.
Applications of Tacheometric Surveying
Tacheometric surveying is widely used in many areas, including civil engineering, construction, mapping, and land surveying. It is also used for calculating elevations and for setting out boundaries and other objects.
What are the advantages of tacheometric surveying?
Advantages of Tacheometric Surveying
Tacheometric surveying offers several advantages over traditional methods of surveying, such as faster calculation of distances, increased accuracy, and the ability to survey inaccessible or difficult terrain. Additionally, it reduces the need for manpower and equipment, providing cost-savings and improved efficiency.
Benefits of Using Tacheometric Surveying
Tacheometric surveying offers numerous benefits, such as its speed, reduced reliance on tapes and chains, low cost, and high precision. This method can be used for the compilation of topographic maps, hydrological surveys, and cross-checking measurements from other methods, among other tasks.
Applications of Tacheometric Surveying
Tacheometric surveying is widely used in many areas, including civil engineering, construction, mapping, and land surveying. It is also used for calculating elevations and for setting out boundaries and other objects.