Methods of Observations, Computations and Plotting

Introduction

Methods of observations, computations, and plotting are essential components of surveying. These methods involve the collection, analysis, and representation of survey data to determine accurate measurements and create detailed plots. In this topic, we will explore the importance of methods of observations, computations, and plotting in surveying, as well as the fundamental concepts and procedures associated with each.

Methods of Observations

Observations in surveying refer to the measurements taken to determine the position, distance, and elevation of points on the Earth's surface. There are three main types of observations: linear measurements, angular measurements, and leveling measurements.

Linear measurements involve measuring distances between points using instruments such as tape measures. Angular measurements, on the other hand, determine the horizontal and vertical angles between points using instruments like theodolites. Leveling measurements are used to determine the difference in elevation between points using leveling instruments.

To take accurate observations, surveyors use various instruments. These include tape measures for linear measurements, theodolites for angular measurements, and levels for leveling measurements. Each instrument has specific procedures for setting up, leveling, and taking measurements.

Once the observations are taken, they need to be reduced and corrected to account for errors and ensure accuracy. This involves applying mathematical formulas and corrections to the raw data.

Computations

Computations in surveying involve the mathematical calculations performed to analyze and process survey data. There are three main types of computations: linear computations, angular computations, and leveling computations.

Linear computations involve calculating distances, bearings, and offsets between points. Angular computations determine the horizontal and vertical angles between points. Leveling computations involve determining the difference in elevation between points.

To perform these computations, surveyors use mathematical formulas and equations. Trigonometric functions, interpolation, and least squares adjustment are commonly used in surveying computations. Trigonometric functions are used to calculate distances and angles, interpolation is used to estimate values between known data points, and least squares adjustment is used to adjust survey data to minimize errors.

A step-by-step walkthrough of typical computation problems helps surveyors understand and apply the necessary calculations. This includes calculating distance and bearing between two points, determining the elevation of a point, and adjusting survey data using least squares.

Plotting

Plotting in surveying involves the graphical representation of survey data on maps, plans, and profiles. There are three main types of plots: planimetric plots, topographic plots, and profile plots.

Planimetric plots represent the horizontal positions of survey features, such as boundaries, roads, and buildings. Topographic plots show both the horizontal and vertical positions of features, including contour lines to represent elevation. Profile plots display the vertical cross-section of the terrain along a specific line.

To create plots, surveyors use various instruments and tools. These include graph paper for manual plotting and drawing instruments like rulers, compasses, and protractors. Computer-aided design (CAD) software is also commonly used for digital plotting.

The procedures for plotting survey data involve scaling and transferring measurements onto graph paper or CAD software, drawing lines and curves to represent survey features, and labeling and annotating the plot with relevant information.

Real-World Applications and Examples

Methods of observations, computations, and plotting are applied in various fields of surveying. Land surveying involves determining property boundaries, creating topographic maps, and providing data for construction projects. Construction surveying is used to stake out building locations, establish reference points, and ensure accurate construction. Geodetic surveying focuses on measuring large-scale distances and positions on the Earth's surface for mapping and navigation purposes.

Advantages and Disadvantages

Methods of observations, computations, and plotting offer several advantages in surveying. They provide accurate and precise results, allowing for reliable measurements and data analysis. These methods also facilitate efficient data processing, enabling surveyors to analyze large amounts of data quickly. Additionally, plotting survey data provides a clear visualization of the surveyed area and its features.

However, there are also some disadvantages to consider. The process of observations, computations, and plotting can be time-consuming, especially for large-scale surveys. There is also the potential for human error in taking measurements, performing calculations, and creating plots. Furthermore, the equipment and software required for these methods can be costly.

Conclusion

In conclusion, methods of observations, computations, and plotting are fundamental to the field of surveying. They enable surveyors to collect accurate data, perform necessary calculations, and create detailed plots. Understanding and applying these methods are essential for ensuring the accuracy and reliability of surveying results.

Summary

Methods of observations, computations, and plotting are essential components of surveying. Observations involve measuring distances, angles, and elevations using instruments such as tape measures, theodolites, and levels. Computations involve mathematical calculations to analyze survey data, including linear computations, angular computations, and leveling computations. Plotting involves representing survey data on maps, plans, and profiles using graph paper, drawing instruments, or CAD software. These methods have applications in land surveying, construction surveying, and geodetic surveying. They offer advantages such as accurate results, efficient data processing, and clear visualization, but also have disadvantages such as time-consuming processes, potential for human error, and costly equipment and software.

Analogy

Imagine you are an explorer mapping a new territory. You need to carefully observe and measure the distances, angles, and elevations of various landmarks. Once you have collected all the necessary data, you perform calculations to determine the precise positions and heights of these landmarks. Finally, you create a detailed map, plotting all the information you have gathered. This map will serve as a valuable resource for future explorers and travelers.