Types of Survey
Understanding Plane Survey and Geodetic Survey in Civil Engineering and Surveying Applications.
Introduction
Surveying is the science and art of determining the relative positions of points on, above, or below the surface of the earth. It is one of the fundamental branches of civil engineering and plays an essential role in planning, design, and construction projects.
Based on the curvature of the earth and the area covered, surveying is broadly classified into two major types:
- Plane Survey
- Geodetic Survey
In plane surveying, the curvature of the earth is neglected, whereas geodetic surveying considers the spherical shape of the earth. :contentReference[oaicite:0]{index=0}
Plane Survey
Plane surveying is the type of surveying in which the surface of the earth is considered as a flat plane and the curvature of the earth is neglected. It is suitable for small areas where the errors due to earth curvature are negligible. :contentReference[oaicite:1]{index=1}
Main Assumption
Surface of Earth Considered Plane
Characteristics of Plane Surveying
- Curvature of earth is ignored
- Suitable for small areas
- Uses plane geometry and trigonometry
- Survey lines are considered straight
- Triangles formed are plane triangles
- Less complex calculations
Applications
- Building construction
- Road and highway projects
- Small irrigation works
- Land subdivision surveys
- Topographical surveys for local projects
Advantages
- Simple and economical
- Quick field calculations
- Suitable for ordinary engineering works
Geodetic Survey
Geodetic surveying is the type of surveying in which the spherical shape and curvature of the earth are taken into account. It is used for large areas and highly precise engineering works. :contentReference[oaicite:2]{index=2}
Main Assumption
Spherical Shape of Earth Taken Into Account
Characteristics of Geodetic Surveying
- Earth curvature is considered
- Suitable for large areas
- Uses spherical trigonometry
- Provides very high accuracy
- Survey lines are curved
- Triangles formed are spherical triangles
Applications
- National mapping projects
- GPS and satellite positioning
- Long-span bridges and tunnels
- Railway and highway alignment
- Large irrigation and river valley projects
Advantages
- Very high precision
- Suitable for large-scale projects
- Provides accurate control networks
Difference Between Plane Survey and Geodetic Survey
| Basis | Plane Survey | Geodetic Survey |
|---|---|---|
| Earth Surface | Considered flat | Considered curved |
| Area Covered | Small area | Large area |
| Accuracy | Moderate | Very high |
| Geometry Used | Plane geometry | Spherical trigonometry |
| Applications | Local engineering projects | National and regional projects |
Importance of Surveying
- Preparation of maps and plans
- Construction layout and alignment
- Boundary determination
- Infrastructure development
- Topographical and geological studies
- Planning of irrigation and transportation systems
Conclusion
Surveying is an essential part of civil engineering and infrastructure development. Plane surveying is suitable for small-scale projects where earth curvature can be neglected, while geodetic surveying is required for large-scale and high-precision projects where the curvature of the earth must be considered.
Understanding the differences between these two types of surveying helps engineers choose the appropriate method for accurate measurements and successful project execution.
Author
Mohan Dangi (Gold Medalist)
Civil Engineer | Geotechnical Engineer
References
- B.C. Punmia – Surveying Volume I
- S.K. Duggal – Surveying
- R. Agor – Surveying and Levelling
- Standard Civil Engineering Surveying Manuals
- National and International Surveying Standards
Disclaimer
This article is intended for educational and informational purposes only. Surveying methods, assumptions, and standards may vary depending on project requirements, geographical conditions, and applicable engineering codes. Readers are advised to consult professional guidelines and standard surveying references before applying these concepts in practical projects.
0 Comments