Fundamentals of Surveying

Fundamentals of Surveying

Contents

Define the term Surveying 2

Recall the Primary Division of Surveying 2

Classify Surveying on the basis of the following: i. Nature of Field Survey, ii. Object of Survey, iii. Instrument Used 3

Recall the Principle of Surveying 5

Locating new points by measurement of minimum two reference points 6

Define the following terms: i. Plan, ii. Map iii. Scale 8

List various Scales used in the Surveying 8

Describe Errors due to the wrong Scales 10

Recall The fieldwork of the Surveyor 11

Recall Office work of the Surveyor 12

Describe care and adjustment of the Instrument 13

Define the following Terms: i. Precision, ii. Accuracy, iii. Errors 14

Differentiate between Precision and Accuracy 15

List various types of Error 16

Recall different Sources of Errors 17

Define Probability Curve 18

Recall the following terms: i. Principle of Least Square, ii. Most Probable Value, iii. Most Probable Error 18

Describe Errors in the computed Results 19

Define the term Surveying

Surveying is a branch of engineering that deals with the determination of the relative position of points and physical and cultural features on or near the surface of the earth and the representation of that information on maps, plans, and sections. Surveying involves the use of mathematical, geometrical, and technological tools to collect, analyse, and present data about physical and cultural features. The goal of surveying is to provide accurate and precise information about the location, shape, and dimensions of these features, which can then be used for a wide range of purposes, including construction, mapping, land use planning, and environmental protection. Surveying is an essential discipline in many fields, including civil engineering, construction, geography, and land surveying, and it plays a critical role in ensuring that projects are completed safely, efficiently, and effectively.

Recall the Primary Division of Surveying

The primary division of surveying can be categorised into two main areas: Geodetic Surveying and Engineering Surveying.

  1. Geodetic Surveying: This type of surveying deals with the measurement of large distances and angles over the surface of the earth. It involves the use of complex mathematical models and sophisticated instrumentation to determine the exact location of points on the earth’s surface. Geodetic surveying is often used for mapping and boundary determination, as well as for the establishment of control points for other types of surveys.
  2. Engineering Surveying: This type of surveying deals with the measurement of smaller distances and angles for the purpose of construction and land development. It includes a wide range of activities, such as land and topographic surveying, construction layout, and as-built surveys. Engineering surveying is focused on providing the necessary information for the design, construction, and maintenance of infrastructure, buildings, and other structures.

These two types of surveying complement each other and are used in conjunction with each other to provide comprehensive information for various purposes. Geodetic surveying provides the framework for engineering surveying, while engineering surveying provides the detailed information necessary for construction and development.

Classify Surveying on the basis of the following: i. Nature of Field Survey, ii. Object of Survey, iii. Instrument Used

  1. Classifying Surveying based on the Nature of Field Survey:

i. Ground Surveying: This type of surveying involves taking measurements and observations on the ground, usually with hand-held instruments. Ground surveying is used for a variety of purposes, including boundary surveys, topographic surveys, and construction layout surveys.

ii. Aerial Surveying: This type of surveying involves the use of aerial platforms, such as aeroplanes, helicopters, or drones, to collect information about the earth’s surface. Aerial surveying is often used for large-scale mapping projects, for monitoring changes in land use, and for natural resource management.

  1. Classifying Surveying based on the Object of Survey:

i. Cadastral Surveying: This type of surveying is focused on the measurement and mapping of boundaries for the purpose of land ownership and property rights. Cadastral surveys are used for the creation of property deeds, the establishment of boundary markers, and the resolution of boundary disputes.

ii. Geodetic Surveying: This type of surveying deals with the measurement of large distances and angles over the surface of the earth. Geodetic surveying is used for mapping and boundary determination, as well as for the establishment of control points for other types of surveys.

iii. Topographic Surveying: This type of surveying focuses on the measurement and mapping of natural and cultural features on the earth’s surface, such as hills, valleys, rivers, and buildings. Topographic surveying is used for land use planning, natural resource management, and infrastructure development.

  1. Classifying Surveying based on the Instrument Used:

i. Traditional Surveying: This type of surveying involves the use of traditional survey instruments, such as chains, tapes, and levels, to collect data. Traditional surveying is still widely used, especially for smaller projects, and is often seen as a less expensive alternative to modern surveying methods.

ii. Modern Surveying: This type of surveying involves the use of advanced instrumentation, such as total stations, GPS receivers, and laser scanners, to collect data. Modern surveying is used for a wide range of purposes and is often seen as more efficient and accurate than traditional surveying methods.

Recall the Principle of Surveying

Surveying is a process of measuring and mapping the earth’s surface to determine its features, size, and position. The Principle of Surveying refers to a set of fundamental principles that guide the surveying process. Recall of these principles is essential for surveyors to ensure accuracy, precision, and reliability of their measurements.

The main principles of surveying are,

  • To work from whole to the part
  • Locating new points by measurement of minimum two reference points

Working from the whole to the part:

The main principle of this method is establishing the survey work from the whole to the part.

For example, if you are going to take surveys for vast land first, you have to fix systematic control points with high precision around the area—a boundary line formed by connecting the points which are the main skeleton drawing of the survey.

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The survey points are established by triangulation or traverse around the area. Then the triangles are broken into small areas and can be measured by less workmanship.

The primary purpose of work from the whole to the part survey is to avoid the error. In case the survey works are established by part to whole, then we have to face many mistakes in the surveying.

Locating new points by measurement of minimum two reference points

Two different independent processes have to be done to fix a new point. The two different methods can cross-check together.

From the above picture, C is new, which has to be fixed & point A, B are the given points.

  • Now the point C can be fixed by measuring the distance of AC & BC; it is one method of process.
  • A perpendicular line may be drawn from point C to baseline AB. Now we have got two different possibilities to locate point C by the line CD.