What is Traverse Surveying? Methods of Traverse Surveying
What is Traverse Surveying? Methods of Traverse Surveying
What is Traverse Surveying?
Traversing is a sort of survey in which a network of connected survey lines forms the framework and the survey lines’ directions and lengths are measured using an angle measuring instrument and tape or chain, respectively.
Traverse surveying is a means of accurately surveying a field or other area by establishing a network of fixed points and measuring the distances between them.
This type of surveying is often used in conjunction with other surveying techniques, such as leveling and triangulation, to produce a more detailed map or survey of an area.
Traverse is a surveying approach for establishing control networks. Geodesy makes use of it as well.
Traverse networks are constructed by installing survey stations along a line or course of travel and then using the previously surveyed sites as a base for surveying the following point.
There are numerous advantages to traverse networks, including:
Only a few observations are required at each station, but other survey networks require a large number of angular and linear measurements to be made and assessed.
The strength of figure considerations that occur in triangular systems are not present in traverse networks.
There is less need for scouting and organizing.
In contrast to other methods that may require the survey to be completed along a hard polygon shape, the traverse can alter to any shape and thus accommodate a wide range of terrains.
Scale inaccuracy does not accumulate as the traverse is carried out. Increase the distance between stations to avoid azimuth swing errors.
Traverse surveying is classified into two types. They are as follows:
- Open traverse: When a traverse begins at one location and ends at another, it is considered to be an open traverse, as shown in the picture. Unclosed traverse is another name for open traverse. It is appropriate for surveying highways, coastal lines, and so on.
- Closed Traverse: When a traverse forms a closed circuit, as shown in the figure, it is considered to be a closed traverse.
In this situation, the traverse’s starting and ending positions are both the same. It is appropriate for surveying the boundaries of ponds, sports fields, and woodlands, among other things.
Methods of Traversing
The traversal is done using four alternative ways, which are categorized based on the survey instrument utilized. The methods are as follows.
Chain Traversing
Only linear measurements are used to traverse a chain. As a result, chain or tape are sufficient for chain traversal. The chain angles concept is used to compute the angle between neighboring traverse lines.
Chain traversing is used in places where triangulation would be difficult to do, such as ponds.
Only linear measurements are used to traverse a chain. As a result, chains or tape are sufficient for chain traversal.
The chain angles concept is used to compute the angle between neighboring traverse lines. Chain traversing is used in places where triangulation would be difficult to do, such as ponds.
Compass Traversing
Compass traversing involves taking both linear and angular measurements of traverse lines with a chain or prismatic compass. Fore and back bearings are measured, and necessary modifications for nearby attractions are made.
If a closing mistake is obtained while charting a traverse, the Bowditch rule is used to correct the problem. There are several varieties of compass used in navigation, including:
- Compass with a lens
- Compass used by surveyors
- Compass Prismatic
- Compass Trough
Compass traversing (by free needle)
The magnetic bearings of the survey lines are traversed using a compass and a compass, and the length of the lines is measured using tape or a chain and a compass.
Each traverse station determines the direction of a magnetic meridian independently. The procedure is also known as the free or lost needle method.
A theodolite with a compass can also be used to measure the magnetic bearings of the traverse line.
However, the method is not as accurate as transit tape traversing. The methods of collecting details are nearly identical to those used in chain surveying.
However, the method is not as accurate as transit tape traversing. The methods of collecting details are nearly identical to those used in chain surveying.
Traversing is a type of survey in which numerous connected survey lines constitute the directions, and the framework and lengths of the survey line are measured using an angle (or direction) measurement equipment and a tape (or chain) accordingly.
It is known as a closed traverse. When the lines connect to form a circuit that returns to the beginning place. If the circuit terminates somewhere else, it is said to be an open traverse.
The various techniques of traversing have been thoroughly discussed in Angle Measurement units. An angle is a difference in the directions of two intersecting lines.
Theodolite Traversing
In this approach, linear measurements are taken using the chain method, and angular measurements are taken using a theodolite.
The magnetic bearing of the first traverse line is measured with a theodolite, and the magnetic bearing of the remaining sides is determined from that. When compared to other ways, this method is quite accurate.
Theodolite traversing (by fast needle)
The travelling by rapid needle method refers to the process of measuring the magnetic bearings of traverse lines with a theodolite equipped with a compass.
Directions are measured in theodolite traversing in the form of bearings, deflection angles, angles to the right, interior angles, or azimuths using a theodolite and distance with a tape, electric distance measuring (EDM) equipment, or a tachometer.
Bearings are measured with a theodolite and a compass using either the loose needle method or the fast needle method.
If the angles are measured by the deflection angles technique, angle to the right, traverse, they are referred to as deflection angle traverse.
It is especially useful in urban surveys where triangulation is not possible.
The theodolite is a complicated instrument used primarily for accurate measurement of horizontal and vertical angles up to 10′′ or 20′′, depending on the instrument’s least count. The theodolite is sometimes referred to as a universal instrument because of its many applications.
Theodolites can be used for a variety of purposes, including:
- Horizontal Angle Measuring
- Measuring vertical angles
- Deflection angles are measured.
- Magnetic bearings are measured.
- Measuring the horizontal distance between two points
Theodolites Traversing. There are two kinds of surveying:
- Non-transit theodolite
- The transit theodolite
The telescope of the transit theodolite can be rotated through a complete rotation about its horizontal axis in a vertical plane. The telescope of the non-transit theodolite cannot be turned through a complete revolution in the vertical plane.
However, it can be rotated to a certain extent in the vertical plane to measure the angle of elevation or depression.
- Vernier theodolites are theodolites that have been fitted with a vernier scale.
- Vernier theodolites—when fitted with a vernier scale
The diameter of the central horizontal graduated circle defines the size of the theodolite. In a “10 cm theodolite,” for example, the breadth of the center graded ring is 10 cm. In an engineering survey, 8 cm to 12 cm theodolites are commonly utilized.
Plane Table Traversing
In the case of plane table traveling, the traverse is measured and plotted on paper at the same time.
The plane table equipment is installed one by one at each traverse station in either a clockwise or anti-clockwise direction.
On paper, the sides of each traverse station are drawn to size. If there is a closure error, graphical approaches are employed to correct it.
It is beneficial in the following situations:
- It is best suited for small-scale surveys.
- It is often utilized in industrial locations where compass surveys fail.
- It is used to fill in information between stations determined by triangulation or theodolite traversing.
Plan table traversing (by fast needle)
One of the earliest surveying instruments is the plane table. The fact that field observations and charting take place concurrently distinguishes plane table surveying.
It is highly suited for surveying detail near theodolite stations and is widely used to record topographic features in engineering surveys.
Photogrammetry is now the primary approach for mapping vast areas on a tiny scale. Plane table surveying, often known as ‘plane tabling,’ is employed as a supplement method since it is simple and economical.
Traversing methods advantages and disadvantages
Chain Traversing
Advantages
- Easy for use and cheap
- Accurate
- Can be done as a one-man job
- Accuracy is not affected by the skill of the surveyor or by an error in the transit
Disadvantages
- It is only applicable to a restricted number of surveys
- Difficult to set up at a high angle and to traverse long distances.
- The method is often used in industrial areas and is often taken by inexperienced surveyors.
Compass Traversing
Advantages
- Can be applied to any survey
- Simple and easy to use
- Accurate
- Not affected by the skill of the surveyor or by the error in the transit
- Accuracy is affected by the medium and sensitivity of the compass
Disadvantages
- One of the most difficult methods.
- Requires a high degree of accuracy and skill.
Theodolite Traversing
Advantages
- It is easy to use, cheap, and accurate.
Disadvantages
- Highly technical equipment is required.
- The accuracy of traversing by theodolite depends on the skill of the surveyor and the quality of the equipment. It is very difficult to traverse at high angles and over long distances.
Plane Table Traversing
Advantages
- Easy for use and cheap.
Disadvantages
- Difficult to set up at a high angle and to traverse long distances.
- Surveyors tend to take bad bearings because it is easy to take a bearing.
- Difficult to use if the angle is over 55 degrees.
The theodolite and plane table are not commonly used nowadays, but there are still places where they are used.
Traverse Surveying FAQs
What is the traversing method in surveying?
A traverse is a surveying approach for establishing control networks. Geodesy makes use of it as well.
Traverse networks are constructed by installing survey stations along a line or course of travel and then using the previously surveyed sites as a base for surveying the following point.
What is a simultaneous traverse?
A simultaneous traverse is one in which two or more different instruments are used to establish points.
It is often used when there isn’t enough time to take a set of bearings. Another advantage of the method is that it can be done by either a long-distance or short-distance surveyor.
How many methods of traversing are there?
There are four major methods of traversing, depending on the instrument used to determine the relative directions of the traverse lines: traversal of the chain Traversing the compass Theodolite traversing and Plane table traversing
What are the methods of traversing by theodolite?
Traversal Methods
- Method of magnetic bearing.
- Method of the loose needle
- The method of direct angle.
- Angle technique is included.
- Method of Deflection Angle
What are the types of traversing?
Traverse surveying is classified into two types. They are as follows:
Closed traverse: A closed traverse occurs when the lines create a circuit that terminates at the starting location.
Open traverse: An open traversal occurs when the lines forming a circuit terminate somewhere other than the starting location.
What is traverse in data structures?
Traversing a data structure entails “visiting” or “touching” the structure’s elements and doing anything with the data. (Traversing is also known as iterating over the data structure.)
What is theodolite traverse by fast needle?
Fast Needle Method of Theodolite Traversal. The travelling by rapid needle method refers to the process of measuring the magnetic bearings of traverse lines with a theodolite equipped with a compass.
What is compass traversing?
A compass traverse is a means of filling in detail on topographic, geologic, or other maps. It is a method of surveying a route such as a stream, path, or the edge of an outcrop using a series of traverse legs, the bearing of each of which is recorded by compass and the length measured directly in the field.
What is Chain traversing?
Chain traverse is a method of surveying. Only linear measurements are taken when traversing a chain. The angle between consecutive traverse lines is calculated using the chain angles concept. Chain traversing is done in places like ponds.
What is plane table traversing?
Plane Table Traversing is also known as plane tabling. It is a surveying method where sheets of paper are placed on adjustable frames which are attached to a transit instrument. The lines are made on the paper by means of line drawing instruments, such as pencils, pens or paint brushes.
Plane table Surveying advantages?
The Benefits of Plane Table Surveying Because the observations and graphing are done concurrently, there is no possibility of missing important facts. Check lines can be used to check for plotting faults and mistakes. As long as the lay of the land is visible, irregular objects can be precisely mapped.
What is the purpose of traverse?
The objective of the traverse is to locate the unknown points relative to each other and to locate all points within the traverse relative to a common grid.
Three types of initial data are required. They are the coordinates and height of a starting point, as well as an azimuth to a visible azimuth mark.
What is traverse operation?
A traverse operation consists of moving from one point to the next, in a linear or circular fashion. The traverse can thus be described as a series of operations of this type. Accurate traverses are usually conducted with some form of traversing instrument.
All three types of traversing operations are uniformly sampling operations.
How is traverse calculated in survey?
Divide the sum of the double areas by two to get the area of the traverse. The latitude AB’ is a (+) latitude for the side AB, and (B’B+C’C) xAB’ is twice the area of the triangle AB’B.
